Key Words for Key Drugs
The following list is a compilation of the drugs that are most likely to appear on examinations. The brief descriptions should serve as a rapid review. The list can be used in 2 ways. First, cover the column of properties and test your ability to recall descriptive information about drugs picked at random from the left column; second, cover the left column and try to name a drug that fits the properties described. The numbers in parentheses at the end of each drug description denote relevant chapter.
Common abbreviations and acronyms: ACE, angiotensin converting enzyme; ADHD, attention deficit hyperactivity disorder; ANS, autonomic nervous system; AV, atrioventricular; BP, blood pressure; CNS, central nervous system; COMT, catechol-O-methyl transferase; DMARD, disease-modifying antirheumatic drug; ENS, enteric nervous system; EPS, extrapyramidal system; GABA, 
-aminobutyric acid; GI, gastrointestinal; HF, heart failure; HR, heart rate; HTN, hypertension; LMW, low molecular weight; MAO, monoamine oxidase; MI, myocardial infarct; NSAID, nonsteroidal anti-inflammatory drug; RA, rheumatoid arthritis; SANS, sympathetic autonomic nervous system; TCA, tricyclic antidepressant; TNF, tumor necrosis factor; Tox, toxicity; WBCs, white blood cells.
Drug Properties Abciximab Monoclonal antibody that inhibits the binding of platelet glycoprotein IIb/IIIa (GPIIb/IIIa) to fibrinogen. Used to prevent clotting after coronary angioplasty and in acute coronary syndrome. Eptifibatide and tirofiban are also GPIIb/IIIa inhibitors. (34) Acetaminophen Antipyretic analgesic: very weak cyclooxygenase inhibitor; not anti-inflammatory. Less GI distress than aspirin but dangerous in overdose. Tox: hepatic necrosis. Antidote: acetylcysteine. (36) Acetazolamide Carbonic anhydrase-inhibiting diuretic acting in the proximal convoluted tubule: produces a NaHCO3 diuresis, results in bicarbonate depletion and metabolic acidosis. Has self-limited diuretic but persistent bicarbonate-depleting action. Used in glaucoma and mountain sickness. Tox: paresthesias, hepatic encephalopathy. Dorzolamide and brinzolamide are topical analogs for glaucoma. (15) Acetylcholine Cholinomimetic prototype: transmitter in CNS, ENS, all ANS ganglia, parasympathetic postganglionic synapses, sympathetic postganglionic fibers to sweat glands, and skeletal muscle endplate synapses. (6, 7) Acyclovir Antiviral: inhibits DNA synthesis in herpes simplex virus (HSV) and varicella-zoster virus (VZV). Requires activation by viral thymidine kinase (TK- strains are resistant). Tox: behavioral effects and nephrotoxicity (crystalluria) but minimal myelosuppression. Famciclovir, penciclovir, and valacyclovir are similar but with longer half-lives. (49)
Adenosine Antiarrhythmic: miscellaneous group; parenteral only. Hyperpolarizes AV nodal tissue, blocks conduction for 10-15 s. Used for nodal reentry arrhythmias. Tox: hypotension, flushing, chest pain. (14) AlbuterolPrototypic rapid-acting 
2 agonist; important use in acute asthma. Tox: tachycardia, arrhythmias, tremor. Other drugs with similar action: metaproterenol, terbutaline. Slow-acting analogs: formoterol, salmeterol; used for prophylaxis. (9, 20)
Alendronate Bisphosphonate: chronic treatment with low doses increases bone mineral density and reduces fractures. Higher doses lower serum calcium. Used in osteoporosis and for the hypercalcemia in Paget's disease and malignancies. Tox: esophageal irritation at low oral doses. Renal dysfunction and osteonecrosis of the jaw in high doses. Other bisphosphonates include etidronate, pamidronate, risedronate, etc. (42) Allopurinol Irreversible inhibitor of xanthine oxidase; reduces production of uric acid. Used in gout and adjunctively in cancer chemotherapy. Inhibits metabolism of purine analogs (eg, mercaptopurine, azathioprine). Febuxostat is similar. (36) Alteplase (t-PA) Thrombolytic: human recombinant tissue plasminogen activator. Used to recanalize occluded blood vessels in acute MI, severe pulmonary embolism, stroke. Reteplase and tenecteplase are similar. Streptokinase is a bacterial protein with thrombolytic properties. Tox: bleeding. (34) Amiloride K+-sparing diuretic: blocks epithelial Na+ channels in cortical collecting tubules. Tox: hyperkalemia. (15)
Amiodarone Group 3 (and other groups) antiarrhythmic: broad spectrum; blocks sodium, potassium, calcium channels, receptors. High efficacy and very long half-life (weeks to months). Tox: deposits in tissues; skin coloration; hypo- or hyperthyroidism; pulmonary fibrosis; optic neuritis. (14) Amphetamine Indirect-acting sympathomimetic: displaces stored catecholamines in nerve endings. Marked CNS stimulant actions; high abuse liability. Used in ADHD, for short-term weight loss, and for narcolepsy. Tox: psychosis, HTN, MI, seizures. Other indirect-acting sympathomimetics that displace catecholamines: ephedrine, pseudoephedrine, methylphenidate, tyramine. (9, 32) Amphotericin B Antifungal: polyene commonly a drug of choice for some systemic mycoses; binds to ergosterol to disrupt fungal cell membrane permeability. Tox: chills and fever, hypotension, nephrotoxicity (dose limiting; less with liposomal forms). (48) Ampicillin Penicillin: wider spectrum than penicillin G, susceptible to penicillinases unless used with sulbactam. Activity similar to that of penicillin G, plus E coli, H influenzae, P mirabilis, Shigella.Synergy with aminoglycosides versus Enterococcus and Listeria. Tox: penicillin allergy; more adverse effects on GI tract than other penicillins; maculopapular skin rash. Amoxicillin has greater oral bioavailability and less GI effects; also used with clavulanate, a penicillinase inhibitor. (43) Anastrozole Aromatase inhibitor: prototype inhibitor of the enzyme that converts testosterone to estradiol. Used in estrogen-dependent breast cancer. Letrozole is similar; exemestane is an irreversible aromatase inhibitor. (40, 54) Aspirin NSAID prototype: inhibits cyclooxygenase (COX)-1 and -2 irreversibly. Antiplatelet agent as well as antipyretic, analgesic and anti-inflammatory drug. Tox: GI ulcers, nephrotoxicity, rash, hypersensitivity leading to bronchoconstriction, salicylism. Other NSAIDs: ibuprofen, indomethacin, ketorolac, and naproxen. (34, 36) Atenolol Beta1-selective blocker: low lipid solubility, less CNS effect; used for HTN, angina. (Mnemonic: Generic names of 1-selective blockers start with A through M except for carteolol, carvedilol, and labetalol.) Tox: asthma, bradycardia, AV block, heart failure. (10)
Atropine Muscarinic cholinoceptor blocker prototype: lipid-soluble, CNS effects; antidote for cholinesterase poisoning. Tox: "red as a beet, dry as a bone, blind as a bat, mad as a hatter," urinary retention, mydriasis. Cyclopentolate, tropicamide: antimuscarinics for ophthalmology; cause cycloplegia and mydriasis. Glycopyrrolate: antimuscarinic with decreased CNS effects. (8, 57) Azithromycin Macrolide antibiotic: similar to erythromycin but greater activity against H influenzae, chlamydiae, and streptococci; long half-life with renal elimination. Tox: GI distress but no inhibition of drug metabolism. Clarithromycin is similar but has a shorter half-life, and inhibits drug metabolism. (44) Baclofen GABA analog, orally active: spasmolytic; activates GABAB receptors in the spinal cord. (27)
Benztropine Muscarinic cholinoceptor blocker: centrally acting antimuscarinic prototype for parkinsonism. Tox: excess antimuscarinic effects. (8, 28) Botulinum Toxins produced by Clostridium botulinum:enzymes that cleave nerve terminal proteins (synaptobrevin, others) and block transmitter release from acetylcholine vesicles. Injected to treat muscle spasm, smooth wrinkles, and reduce excessive sweating. Tox: paralysis. (6, 27) Bromocriptine Ergot derivative: prototype dopamine agonist in CNS; inhibits prolactin release. Used in hyperprolactinemia and a rarely used alternative drug in parkinsonism. Tox:CNS, dyskinesias, hypotension. (16, 28, 37) Bupivacaine Long-acting amide local anesthetic prototype. Tox: greater cardiovascular toxicity than most local anesthetics. (26) Buprenorphine Opioid: long-acting partial agonist of 
receptors. Analgesic (not equivalent to morphine) and effective for detoxification and maintenance in opioid dependence. Other mixed agonist-antagonists: nalbuphine activates 
and weakly blocks receptors; pentazocine, agonist and weak antagonist or partial agonist. (31) BupropionAntidepressant & used in smoking cessation: mechanism uncertain, but no direct actions on CNS amines. Tox: agitation, anxiety, aggravation of psychosis and, at high doses, seizures. (30) Captopril ACE inhibitor prototype: used in HTN, diabetic nephropathy, and HF. Tox: hyperkalemia, fetal renal damage, cough ("sore throat"). Other "prils" include benazepril, enalapril, lisinopril, quinapril. (11, 13, 17) Carbamazepine Antiseizure drug: used for tonic-clonic and partial seizures; blocks Na+ channels in neuronal membranes. Drug of choice for trigeminal neuralgia; backup drug in bipolar disorder. Tox: CNS depression, myelotoxic, induces liver drug-metabolizing enzymes, teratogenicity. (24, 29)
Carvedilol Adrenoceptor blocker: racemic mixture, one isomer a nonselective blocker and the other an 
1 blocker. Used in HTN, prolongs survival in HF. Tox: cardiovascular depression, asthma. Labetalolis similar. (10, 11, 13)
Caspofungin Antifungal: echinocandin prototype, inhibitor of (1-3)-glucan synthesis, a cell wall component. Used IV for disseminated Candida and Aspergillus infections. Tox: GI effects, flushing. Increases cyclosporine levels (avoid combination). (48) Cefazolin First-generation cephalosporin prototype: bactericidal beta-lactam inhibitor of cell wall synthesis. Active against gram-positive cocci, E coli, K pneumoniae, but does not enter the CNS. Tox:potential allergy; partial cross-reactivity with penicillins. (43) Ceftriaxone Third-generation cephalosporin: active against many bacteria, including pneumococci, gonococci (a drug of choice), and gram-negative rods. Enters the CNS and is used in bacterial meningitis. Cefotaxime and ceftazidime are other third-generation cephalosporins. (43) CelecoxibSelective COX-2 inhibitor. Less GI toxicity than nonselective NSAIDs. Tox: nephrotoxicity, increased risk of myocardial thrombosis and stroke. (36) Chloramphenicol Antibiotic: broad-spectrum agent; inhibits protein synthesis (50S); uses restricted to backup drug for bacterial meningitis, infections due to anaerobes, Salmonella. Tox: reversible myelosuppression, aplastic anemia, gray baby syndrome. (44) Chloroquine Antimalarial: blood schizonticide used for treatment and prophylaxis in areas in which P falciparum is susceptible. Binds to hemin, causing dysfunctional cell membranes; resistance resulting from efflux via P-glycoprotein pump. Tox: GI distress and skin rash at low doses; peripheral neuropathy, skin lesions, auditory and visual impairment, quinidine-like cardiotoxicity at high doses. (52) Chlorpheniramine Antihistamine first-generation H1 blocker prototype. Tox: less sedation and ANS-blocking action than diphenhydramine. (16)
Chlorpromazine Phenothiazine antipsychotic drug prototype: blocks most dopamine receptors in CNS. Tox: atropine-like, EPS dysfunction, hyperprolactinemia, postural hypotension, sedation, seizures (in overdose), additive effects with other CNS depressants. Other phenothiazines: fluphenazine, trifluoperazine (antipsychotics), prochlorperazine (antiemetic), promethazine (preoperative sedation). (29) Cholestyramine Antihyperlipidemic: bile acid-binding resin prototype that sequesters bile acids in gut and diverts more cholesterol from the liver to bile acids instead of circulating lipoproteins. Used for hypercholesterolemia Tox: constipation, bloating; interferes with absorption of some drugs. Colestipol and colesevelam are similar. (35) Cimetidine H2 blocker prototype: used in acid-peptic disease. Tox:inhibits hepatic drug metabolism; antiandrogen effects. Less toxic analogs: ranitidine, famotidine, nizatidine. (16, 59)
Ciprofloxacin Second-generation fluoroquinolone antibiotic: bactericidal inhibitor of topoisomerases; active against E coli, H influenzae, Campylobacter, Enterobacter, Pseudomonas, Shigella. Tox: CNS dysfunction, GI distress, superinfection, collagen dysfunction (caution in children and pregnant women). Interactions: inhibits metabolism of caffeine, theophylline, warfarin. See also levofloxacin. (46) Cisplatin Antineoplastic: platinum-containing alkylating anticancer drug. Used for solid tumors (eg, testes, lung). Tox: Neurotoxic and nephrotoxic. Carboplatin, oxaliplatin are similar. (54) ClindamycinLincosamide antibiotic: bacteriostatic inhibitor of protein synthesis (50S); active against gram-positive cocci, B fragilis. Tox: GI distress, pseudomembranous colitis. (44) Clomiphene Selective estrogen receptor modulator (SERM): synthetic, used in infertility to induce ovulation by blocking pituitary estrogen receptors. May result in multiple births. (40) Clonidine Alpha2 agonist: acts centrally to reduce SANS outflow, lowers BP. Used in HTN and in drug dependency states. Tox: mild sedation in normal doses, rebound HTN if stopped suddenly. See also methyldopa. (9, 11, 32)
Clopidogrel Antiplatelet agent: irreversibly inhibits platelet ADP receptors and platelet aggregation. Used in transient ischemic attacks and to prevent strokes and restenosis after placement of coronary stents. Tox: bleeding, neutropenia. Ticlopidine is similar, but higher risk of neutropenia and thrombotic thrombocytopenic purpura (TTP). (34) Cocaine Indirect-acting sympathomimetic that blocks amine reuptake into nerve endings: local anesthetic (ester type). Marked CNS stimulation, euphoria; high abuse and dependence liability. Tox: psychosis, HTN, cardiac arrhythmias, seizures. (9, 26, 32) ColchicineMicrotubule assembly inhibitor: reduces macrophage mobility and phagocytosis; used in chronic gout. Tox: GI (often severe), hepatic, renal damage. (36) Cyclophosphamide Antineoplastic, immunosuppressive: cell cycle-nonspecific alkylating agent. Tox: alopecia, GI distress, hemorrhagic cystitis (use mesna), myelosuppression. (54, 55) Cyclosporine Immunosuppressant: immunophilin ligand; inhibits T-cell synthesis of cytokines. Tox: nephrotoxicity, hypertension, peripheral neuropathy, seizures. Tacrolimus and sirolimusare similar. (36, 55) Cytokines, recombinant DNA technology products: aldesleukin (IL-2, used in renal cancer); erythropoietin (epoetin alfa, used in anemias); filgrastim (G-CSF, used in neutropenia); interferon- (used in hepatitis B and C and in cancer); interferon- (used in multiple sclerosis); interferon- (used in chronic granulomatous disease); oprelvekin (IL-11, used in thrombocytopenia); and sargramostim (GM-CSF, used in neutropenia). (33, 36, 49, 54, 55) DantroleneMuscle relaxant: blocks Ca2+ release from sarcoplasmic reticulum of skeletal muscle. Used in muscle spasm (cerebral palsy, multiple sclerosis, cord injury) and in emergency treatment of malignant hyperthermia. (25, 27, 29)
Desmopressin Vasopressin (ADH) analog, more selective for V2 receptors: used for pituitary diabetes insipidus and mild hemophilia A or von Willebrand disease. Vasopressin (ADH), an agonist for V1 and V2 receptors, is used in pituitary diabetes insipidus and bleeding esophageal varices. Conivaptan, an antagonist at V1a and V2 receptors and tolvaptan, an antagonist at V2 receptors, are used for hyponatremia. (15, 34, 37)
Diazepam Benzodiazepine (BZ) prototype: binds to BZ receptors of the GABAA receptor-chloride ion channel complex; facilitates the inhibitory actions of GABA by increasing the frequency of channel opening (compare phenobarbital). Uses: anxiety states, ethanol detoxification, muscle spasticity, status epilepticus. Other benzodiazepines include alprazolam, lorazepam, midazolam & triazolam. Tox:dependence, additive effects with other CNS depressants. (22, 24, 27, 32)
Digoxin Cardiac glycoside prototype: positive inotropic drug for HF, half-life 40 h; inhibits Na+/K+ ATPase, also a cardiac parasympathomimetic. Tox: calcium overload arrhythmias, GI upset. (13, 14)
Diphenhydramine Antihistamine (first-generation) H1 blocker: used in hay fever, motion sickness, dystonias. Tox: antimuscarinic, adrenoceptor blocker, strong sedative. Doxylamine is similar. (16, 59)
Dopamine Neurotransmitter and agonist drug at dopamine receptors: used in shock to increase renal blood flow (low dose) and cardiac output (moderate dose). (6, 9, 13, 21, 28, 29, 37) DoxorubicinAntineoplastic: anthracycline drug (cell cycle-nonspecific); intercalates between base pairs to disrupt DNA functions, inhibits topoisomerases, and forms cytotoxic free radicals. Tox: cardiomyopathy (dexrazoxane is antidote), myelosuppression. Daunorubicinis similar. (54) Doxycycline Tetracycline antibiotic: protein synthesis inhibitor (30S), more effective than other tetracyclines against chlamydia and in Lyme disease; malaria prophylaxis. Unlike other tetracyclines, it is eliminated mainly in the feces and has longer half-life. Tox: see tetracycline. (44, 53) Edrophonium Cholinesterase inhibitor: very short duration of action (15 min). Used in diagnosis of myasthenia gravis and to distinguish myasthenic crisis from cholinergic crisis. (7) Efavirenz Nonnucleoside reverse transcriptase inhibitor (NNRTI): used in combination regimens for HIV. Tox: skin rash, CNS effects, avoid in pregnancy. Other NNRTIs: delavirdine, nevirapine. (49) Enfuvirtide Antiviral: HIV fusion inhibitor used in combination regimens. Tox: injection site reactions and rare hypersensitivity. (49) Enoxaparin LMW heparin: used parenterally for anticoagulation. Primary effect is on factor Xa, less on thrombin. The aPTT test is unreliable. Other LMW heparins include dalteparin, tinzaparin. Tox: bleeding. (34) Entacapone COMT inhibitor: enhances levodopa access to CNS neurons; adjunctive use in Parkinson's disease. Tox:exacerbates levodopa effects. Tolcapone is similar in action and use but can be hepatotoxic. (28) Ephedrine Indirectly acting sympathomimetic: like amphetamine but less CNS stimulation, more smooth muscle effects. In botanicals (eg, ma huang) and products for weight loss that are banned in the United States. Tox: hypertension, stroke, MI. (9, 61) Epinephrine Adrenoceptor agonist prototype: product of adrenal medulla, some CNS neurons. Affinity for all and all receptors. Drug of choice in anaphylaxis; used as hemostatic and as adjunct with local anesthetics; cardiac stimulant; traditional use in asthma. Tox: tachycardia, hypertension, MI, pulmonary edema, and hemorrhage. (6, 9) Ergot alkaloids Ergonovine, ergotamine: cause prolonged vasoconstriction and uterine contraction. Used in migraine and obstetrics. Tox: vasospasm (including coronaries). (16, 28) ErythromycinMacrolide antibiotic: bacteriostatic inhibitor of protein synthesis (50S); activity includes gram-positive cocci and bacilli, M pneumoniae, Legionella pneumophila, C trachomatis. Tox: cholestatic jaundice (avoid estolate in pregnancy), inhibits liver drug-metabolizing enzymes, interactions with cisapride, theophylline, warfarin. Other macrolide antibiotics include azithromycin and clarithromycin. (44) Erythropoietin Hematopoietic growth factor: stimulates RBC production and release from bone marrow. Used in anemia associated with renal failure and anemias secondary to cancer chemotherapy. Darbepoetin alfa has a longer half-life. (33) Etanercept DMARD: recombinant protein that binds TNF-. Infliximab has a similar mechanism of action. Effective in rheumatoid arthritis and other chronic inflammatory diseases. Tox: injection site reactions include erythema, itching, and swelling; possible increased rates of infection and malignancy. (36, 55) Ethambutol Antimycobacterial: inhibitor of arabinogalactan synthesis, a cell wall component; commonly used in standard antitubercular drug regimens. Tox: dose-dependent ocular dysfunction, dizziness, headache, hyperuricemia. (47) Ethanol Sedative-hypnotic: acute actions include impaired judgment, ataxia, loss of consciousness, vasodilation, and cardiovascular and respiratory depression. Chronic use leads to dependence and dysfunction of multiple organ systems; fetal alcohol syndrome. Note: zero-order elimination kinetics. (23, 32) Ethinyl estradiol Synthetic estrogen: used in many hormonal contraceptives. Mestranol is similar. (40) Ethosuximide Anticonvulsant: used in absence seizures; may block T-type Ca2+ channels in thalamic neurons. Tox: GI distress; safe in pregnancy. (24)
Ezetimibe Antihyperlipidemic: cholesterol-lowering drug that inhibits GI transporter of dietary cholesterol and the cholesterol secreted in bile. Used for hypercholesterolemia, usually in combination with a statin. Tox: possible increased risk of hepatic damage when combined with statin. (35) Fentanyl Short-acting potent opioid agonist (see morphine) used commonly in anesthesia and for chronic pain (transdermal form). Remifentanil and sufentanil are similar. (25, 31, 32) Finasteride Antiandrogen: steroid inhibitor of 5-reductase that inhibits synthesis of dihydrotestosterone. Used in benign prostatic hyperplasia and male-pattern baldness. Dutasteride is similar. (40) FlecainideGroup 1C antiarrhythmic prototype: used in ventricular tachycardia and rapid atrial arrhythmias with Wolff-Parkinson-White syndrome. Tox: arrhythmogenic, CNS excitation. (14) Fluconazole Imidazole antifungal: inhibits ergosterol synthesis. CNS entry and renal elimination. Used in esophageal and vaginal candidiasis, in coccidioidomycosis, and in the prophylaxis and treatment of fungal meningitis. Adverse effects similar to those of ketoconazolebut less severe. (48) Fludrocortisone Synthetic corticosteroid: high mineralocorticoid and moderate glucocorticoid activity; long duration of action. Used in Addison's disease. (39) Flumazenil Benzodiazepine receptor antagonist: used to reverse CNS depressant effects of benzodiazepines, zolpidem, eszopiclone and zaleplon. (22, 58) Fluorouracil Antineoplastic: pyrimidine antimetabolite (cell cycle-specific), irreversibly inhibits thymidylate synthase, resulting in dTMP deficiency and "thymine-less" cell death; used mainly for solid tumors. Tox: GI distress, myelosuppression, neurotoxicity. (54) Fluoxetine Antidepressant: selective serotonin reuptake inhibitor (SSRI) prototype. Less ANS adverse effects and cardiotoxic potential than tricyclics. Tox: CNS stimulation, sexual dysfunction, seizures in overdose, serotonin syndrome. Other SSRIs: citalopram, escitalopram, fluvoxamine, paroxetine, sertraline. (30) Flutamide Antiandrogen: prototype androgen receptor antagonist used in prostatic carcinoma. Others: bicalutamide, nilutamide. (40) Furosemide Loop diuretic prototype: blocks Na+/K+/2Cl- transporter in thick ascending limb; high efficacy; used in acute pulmonary edema, refractory edematous states, hypercalcemia, and HTN. Tox: ototoxicity, K+ wasting, hypovolemia, increased serum uric acid. Bumetanide and torsemide differ only in half-life. Ethacrynic acid is similar but causes less hyperuricemia and may even reduce uric acid levels. (13, 15)
Gabapentin Anticonvulsant: structural analog of GABA that facilitates its inhibitory actions in the CNS; used for partial seizures, for neuropathic pain, and in bipolar disorder. Tox: sedation, movement disorders. (24, 27, 29) Ganciclovir Antiviral: effective against herpesviruses (cytomegalovirus [CMV] and herpes simplex virus [HSV]); for CMV requires bioactivation via viral phosphotransferase. Tox:myelosuppression, nephrotoxicity, neurotoxicity. (49) Gemfibrozil Antihyperlipidemic: fibrate prototype used for hypertriglyceridemia. Lowers serum VLDL and triglycerides and increases HDL by activating peroxisome proliferator-activated receptor- nuclear receptors. Tox: GI distress, cholelithiasis, increased risk of myopathy when combined with statins or niacin. (35) Gentamicin Aminoglycoside prototype: bactericidal inhibitor of protein synthesis (30S); active against many aerobic gram-negative bacteria. Narrow therapeutic window; dose reduction required in renal impairment. Tox: renal dysfunction, ototoxicity; once-daily dosing is effective (postantibiotic effect) and less toxic. Amikacin and tobramycin are similar. (45, 51) Glipizide Oral antidiabetic: second-generation, potent sulfonylurea secretagogue. Blocks K+ channels in pancreatic B cells, causing depolarization and release of insulin. Tox: hypoglycemia, weight gain. Related drugs: glyburideand older sulfonylureas such chlorpropamide and tolbutamide; short-acting secretagogues include repaglinide and nateglinide. (41)
Glucagon Hormone from pancreatic A cells. Increases blood glucose via increased cyclic adenosine monophosphate. Used in severe hypoglycemia and as an antidote in -blocker overdose. (41, 58) Haloperidol Antipsychotic butyrophenone: blocks brain dopamine D2 receptors. Tox: marked EPS dysfunction, hyperprolactinemia; fewer ANS adverse effects than phenothiazines. (29)
Halothane General anesthetic prototype: inhaled halogenated hydrocarbon. Tox: cardiovascular and respiratory depression and relaxation of skeletal and smooth muscle. Use is declining because of sensitization of heart to catecholamines and occurrence (rare) of hepatitis. Newer inhaled anesthetics include isoflurane and sevoflurane. (25) Heparin Anticoagulant: large polymeric molecule with activity against thrombin and factor X. Rapid onset, parenteral administration. LMW heparins (eg, enoxaparin) and fondaparinux have a similar mechanism of action, although they are more selective for factor X. Tox: bleeding. Antidote: protamine. (34) Hexamethonium Prototypic ganglion blocker, now obsolete except for research use. Causes marked block of both PANS and SANS, hypotension. Newer analogs trimethaphan, mecamylamine are rarely used. (6) Hydralazine Antihypertensive: arteriolar vasodilator, orally active; used in severe HTN, HF. Minoxidil, a similar but more powerful antihypertensive, is also used topically in baldness. Tox: tachycardia, salt and water retention, lupus-like syndrome (hydralazine). (11, 13) Hydrochlorothiazide Thiazide diuretic prototype: acts in distal convoluted tubule to block Na+/Cl- transporter; used in HTN, HF, nephrolithiasis. Tox: hypersensitivity reactions; increased serum lipids, uric acid, glucose; K+wasting. (11, 13, 15)
Hydroxychloroquine DMARD: immunosuppressant used for rheumatoid arthritis. Tox: rash, GI distress, ocular toxicity, myopathy, neuropathy. Other DMARDs: methotrexate, sulfasalazine, gold salts, penicillamine. (36) Ibuprofen NSAID: nonselective COX inhibitor with analgesic, antipyretic, and anti-inflammatory actions similar to aspirin, but no low-dose antiplatelet effect. Tox: GI, renal. (36) Imipenem Prototype carbapenem antibiotic: active against many aerobic and anaerobic bacteria, including penicillinase-producing organisms; a bactericidal inhibitor of cell wall synthesis. Used with cilastatin (which inhibits metabolism by renal dehydropeptidases). Tox: allergy (partial cross-reactivity with penicillins), seizures. Meropenem and ertapenem are similar but do not require cilastatin and are less likely to cause seizures. (43) Imipramine Tricyclic antidepressant (TCA): blocks reuptake of norepinephrine and serotonin. Tox: atropine-like, postural hypotension, sedation, cardiac arrhythmias in overdose, additive effects with other CNS depressants. Other TCAs: amitriptyline, clomipramine, doxepin. (30) IndinavirAntiviral: HIV protease inhibitor (PI) used as a component of combination regimens in AIDS. Tox: anemia, nephrolithiasis, metabolic disorders, inhibits P450 drug metabolism. Other PIs: amprenavir, nelfinavir, ritonavir (major P450 inhibitor, see below), and saquinavir. (49) IndomethacinNSAID: highly potent. Usually reserved for acute inflammation (eg, acute gout); neonatal patent ductus arteriosus. Tox: GI toxicity, renal damage. (36) Interferon Cytokine: treatment of hepatitis B and C viral infections and some malignancies. Tox: "flu-like" syndrome, myelosuppression, neurotoxicity. (49, 55) Ipratropium Antimuscarinic agent: aerosol for asthma, chronic obstructive pulmonary disease (COPD). Good bronchodilator in 30-60% of patients. Tiotropium is similar with longer action. Not as efficacious as 2 agonists but less toxic in COPD. Tox: dry mouth. (8, 20)
Isoniazid Antimycobacterial: primary drug in combination regimens for tuberculosis; used as sole agent in treatment of latent infection. Metabolic clearance via N-acetyltransferases (genetic variability). Tox:hepatotoxicity (age-dependent), peripheral neuropathy (reversed by pyridoxine), hemolysis (in glucose-6-phosphate dehydrogenase deficiency [G6PD] deficiency). (47) Isoproterenol Beta1 and 2 agonist catecholamine prototype: bronchodilator, cardiac stimulant. Always causes tachycardia because both direct and reflex actions increase HR. Tox: arrhythmias, tremor, angina. (9)
Ivermectin Antihelminthic: drug of choice for onchocerciasis and threadworm infections. Intensifies GABA-mediated neurotransmission in nematodes, but no access to CNS in humans. Tox: in onchocerciasis causes headache, fever, hypotension, joint pain. (53) Ketoconazole Antifungal azole prototype: active systemically; inhibits the synthesis of ergosterol. Used for C albicans, dermatophytosis, and non-life-threatening systemic mycoses. Is sometimes used to suppress adrenocorticoid or gonadal hormone synthesis. Tox: hepatic dysfunction, inhibits steroid synthesis and CYP450-dependent drug metabolism. Others: fluconazole, itraconazole, and voriconazole have a wider spectrum and less inhibitory effects on hepatic cytochromes P450. (39, 40, 48) Ketorolac NSAID: mainly used as a systemic analgesic; only NSAID available in parenteral form; see also aspirin. (36) Lamivudine Nucleoside reverse transcriptase inhibitor (NRTI) also known as 3TC. Least toxic NRTI. Notable for use in chronic hepatitis B in addition to HIV infection. (49) Lamotrigine Newer antiepileptic drug for absence and partial seizures; also used in bipolar affective disorder. Tox: rash, possibly life threatening, especially in pediatric patients. (24, 29) Latanoprost Prostaglandin F2 analog used topically in closed angle glaucoma. Bimatoprost, travoprost are similar. (18)
Leflunomide DMARD: dihydroorotate dehydrogenase inhibitor that arrests T cell proliferation. Used orally in rheumatoid arthritis. Tox: diarrhea, increased liver enzymes. (36, 55) Leuprolide GnRH analog: continuous therapy used to suppress gonadotropin and gonadal hormone synthesis, especially in concert with gonadotropins for ovulation induction and in advanced prostate cancer. Goserelin and nafarelinare similar. Ganirelix is a GnRH receptor antagonist with similar effects. Tox: hot flushes, decreased bone density with prolonged use, gynecomastia (men). (37, 40, 54) Levodopa Dopamine precursor: used in parkinsonism, usually in combination with carbidopa (a peripheral inhibitor of dopamine metabolism). Tox: dyskinesias, hypotension, on-off phenomena, behavioral changes. (28) LevofloxacinFluoroquinolone: Bactericidal inhibitor of topoisomerases; one of several "respiratory" fluoroquinolones (gemifloxacin, moxifloxacin) with greater activity than ciprofloxacin against pneumococci. Tox: see ciprofloxacin. (46) Levonorgestrel Progestin: used in many contraceptives including combined oral contraceptives, progestin-only oral contraceptives, the levonorgestrel IUD, subcutaneous implants, and the Plan B emergency contraceptive. (40) Lidocaine Amide local anesthetic, medium-duration amide prototype: highly selective use-dependent group 1B antiarrhythmic; used for nerve block and acute post-MI ischemic ventricular arrhythmias. Parenteral only. Tox: CNS excitation. Mexiletine: like lidocaine, but orally active, longer duration. (14, 26) LithiumAntimanic prototype: a primary drug in mania and bipolar affective disorders; blocks recycling of the phosphatidylinositol second messenger system. Tox: tremor, diabetes insipidus, goiter, seizures (in overdose); teratogenic potential (Ebstein's malformations) now questionable. (29) Loratadine Second-generation H1 antihistamine: used in hay fever. Tox: Much less sedation than first-generation antihistamines; no ANS effects. Others: desloratadine, cetirizine, fexofenadine. (16)
Losartan Angiotensin AT1 receptor blocker (ARB) prototype: used in HTN. Effects and toxicity similar to those of ACE inhibitors but causes less cough. Other AT1 blockers: candesartan, eprosartan, irbesartan, olmesartan, telmisartan, valsartan. (11, 13, 17)
Lovastatin Antihyperlipidemic: HMG-CoA reductase inhibitor prototype used for hypercholesterolemia. Acts in liver to reduce synthesis of cholesterol and indirectly increase LDL receptor synthesis. Other "statins": atorvastatin, fluvastatin, pravastatin, rosuvastatin, simvastatin. Tox: hepatotoxicity (elevated enzymes), muscle damage, teratogen. (35) Malathion Organophosphate insecticide cholinesterase inhibitor: prodrug converted to malaoxon. Less toxic in mammals and birds because metabolized to inactive products. Other organophosphates: parathion converted to paraoxon, and the nerve gases (eg, sarin, soman). (7, 57) Mannitol Osmotic diuretic: used short term for reduction of intracranial pressure or to promote excretion of renal toxins in hemolysis, rhabdomyolysis. Tox: initial expansion of extracellular fluid volume with resulting hyponatremia, headache, nausea. With excessive use, dehydration and hypernatremia. (15) Mebendazole Antihelminthic: important drug for common nematode infections. Inhibits microtubule synthesis and glucose uptake in nematodes. Tox: GI distress, caution in pregnancy. Albendazole (widely used) and thiabendazole (more toxic) are related antihelminthics. (53) Medroxyprogesterone Progestin: used in combination with an estrogen for treatment of menopausal symptoms and used as a long-acting injection (Depo-Provera) for contraception. (40) MefloquineAntimalarial: unknown mechanism of action. Used for prophylaxis against and treatment of chloroquine-resistant malaria, but resistance emerging. Tox: GI distress, dizziness, seizures in overdose, arrhythmias. (52) Meperidine Opioid analgesic: synthetic, equivalent to morphine in efficacy but orally bioavailable. Strong agonist at opioid receptors; blocks muscarinic receptors; serotonergic activity. Tox: see morphine; normeperidine accumulation may cause seizures, serotonin syndrome with SSRIs. (31) Metformin Oral antidiabetic: prototype biguanide; inhibits hepatic and renal gluconeogenesis, minimal hypoglycemia or weight gain. Tox: GI distress, lactic acidosis possible but rare. (41) Methadone Opioid analgesic: synthetic agonist, equivalent to morphine in efficacy but orally bioavailable and with a longer half-life. Used as analgesic, to suppress withdrawal symptoms, and in maintenance programs. Tox: see morphine. (31, 32) Methimazole Antithyroid drug: inhibits tyrosine iodination and coupling reactions; orally active. Tox: rash, agranulocytosis (rare). Propylthiouracil is similar. (37) Methotrexate Antineoplastic, DMARD, immunosuppressant: cell cycle-specific drug that inhibits dihydrofolate reductase. Major dose reduction required in renal impairment. Tox: GI distress, myelosuppression, crystalluria. Leucovorin rescue used to reduce toxicity. (36, 54, 55) MethyldopaAntihypertensive: prodrug of methylnorepinephrine, a CNS-active 2 agonist. Reduces SANS outflow from vasomotor center. See also clonidine. Tox: sedation, positive Coombs test, hemolysis. (11)
Metoclopramide Prokinetic agent: dopamine D2 receptor agonist used to stimulate upper GI motility in patients with gastroparesis and used as an antiemetic. Tox: restlessness, insomnia, agitation, extrapyramidal effects, elevated prolactin. (59)
Metronidazole Antiprotozoal antibiotic: drug of choice in extraluminal amebiasis and trichomoniasis (tinidazole is equivalent); effective against bacterial anaerobes, including B fragilis and in antibiotic-induced colitis resulting from C difficile. Tox: peripheral neuropathy, GI distress, ethanol intolerance, mutagenic potential. (50, 52) Mifepristone Progestin and glucocorticoid receptor antagonist: used in combination with prostaglandin analogs for medical abortion in early pregnancy. (39, 40) Misoprostol Prostaglandin E1 derivative: orally active prostaglandin used to prevent GI ulcers caused by NSAIDs. Also used with mifepristone as abortifacient. Tox: diarrhea. (18, 40, 59) Montelukast Leukotriene receptor blocker (especially LTD4) used for prophylaxis in asthma. Orally active; once daily administration. Zafirlukast is similar. Tox: minimal (20)
Morphine Opioid analgesic prototype: strong receptor agonist. Poor oral bioavailability. Tox: constipation, emesis, sedation, respiratory depression, miosis, and urinary retention. Tolerance may be marked; high potential for psychological and physiologic dependence. Additive effects with other CNS depressants. (31, 32) Nafcillin Penicillinase-resistant penicillin: narrow spectrum, used for suspected or known staphylococcal infections; not active against methicillin-resistant S aureus (MRSA). Tox: penicillin allergy. Others in group include methicillin (the prototype, rarely used), oxacillin, cloxacillin, and dicloxacillin. (43, 51) Naloxone Opioid receptor antagonist: used to reverse CNS depressant effects of opioid analgesics (overdose or when used in anesthesia). Naltrexone (orally active), a related compound, is used in ethanol dependency states. (31, 58) Neostigmine Cholinesterase inhibitor: prototype synthetic quaternary nitrogen carbamate with little CNS effect. Tox: excess cholinomimetic effects. Pyridostigmine is similar but longer-acting. Physostigmine is a lipid-soluble plant alkaloid. Echothiophate is a rarely used organophosphate cholinesterase inhibitor for topical ophthalmic use. (7, 27) NiacinAntihyperlipidemic: inhibits VLDL synthesis and release of fatty acids from adipose tissue. Lowers LDL cholesterol and triglycerides and raises HDL cholesterol. Tox: flushing, pruritus, liver dysfunction, increased risk of myopathy when combined with statins. (35) Nifedipine Dihydropyridine calcium channel blocker prototype: less cardiac depression than verapamil, diltiazem; used in angina, HTN. Tox:constipation, headache, tachycardia, arrhythmias (avoid rapid-onset forms). Others in the dihydropyridine group include amlodipine, felodipine, nicardipine. (11, 12) Nitric oxide Endogenous vasodilator released from vascular endothelium; neurotransmitter. Mediates vasodilating effect of acetylcholine, histamine, and hydralazine. Active metabolite of nitroprusside and of nitrates used in angina. Used as pulmonary dilator in neonatal hypoxia. Tox: excessive vasodilation, hypotension. (19) Nitroglycerin Antianginal vasodilator prototype: releases nitric oxide (NO) in veins, less in arteries, and causes smooth muscle relaxation. Standard of therapy in angina (both atherosclerotic and variant). Tox: tachycardia, orthostatic hypotension, headache. Oral nitrates: isosorbide dinitrate, isosorbide mononitrate. (12, 13) Norepinephrine Adrenoceptor agonist prototype: acts at all adrenoceptors and 1 adrenoceptors; used as vasoconstrictor. Causes reflex bradycardia. Tox: ischemia, arrhythmias, HTN. (6, 9)
Olanzapine Atypical antipsychotic: high-affinity antagonist at 5-HT2a receptors with minimal extrapyramidal side effects; improves both positive and negative symptoms of schizophrenia. Other atypicals: quetiapine (short half-life), risperidone (possible EPS dysfunction), sertindole (QT prolongation), clozapine (agranulocytosis). (29)
Omeprazole Proton pump inhibitor prototype: irreversible blocker of H+/K+ ATPase proton pump in parietal cells of stomach. Used in GI ulcers, Zollinger-Ellison syndrome, gastroesophageal reflux disease (GERD). Other "prazoles": lansoprazole, pantoprazole, rabeprazole. Tox: hypergastrinemia. (59)
Ondansetron 5-HT3 receptor blocker prototype: very important antiemetic for cancer chemotherapy; also used postoperatively to reduce vomiting. Tox: extrapyramidal effects. Other "setrons": granisetron,dolasetron, palonosetron. (16, 59)
Oseltamivir Antiviral: neuraminidase inhibitor blocking release of mature virions of influenza A and B and decreasing their infectivity. Prophylactic and shortens duration of flu symptoms. Zanamivir is similar in action and use. (49) Oxybutynin Muscarinic cholinoceptor blocker: used to relieve bladder spasm and incontinence. Tolterodine, weaker but more selective for M3 receptors, has similar uses. (8)
Paclitaxel Antineoplastic plant alkaloid: cell cycle (M phase)-specific agent; inhibits mitotic spindle disassembly. Tox: hematotoxicity, peripheral neuropathy, hypersensitivity reactions. Docetaxel is similar. (54) PenicillamineChelator, immunomodulator: treatment of copper, lead, mercury, and arsenic poisoning. Also used in Wilson's disease and formerly used in rheumatoid arthritis. (36, 57) Penicillin GPenicillin prototype: active against common streptococci, gram-positive bacilli, gram-negative cocci, spirochetes (drug of choice in syphilis), and enterococci (if used with an aminoglycoside); penicillinase susceptible. Tox: penicillin allergy. (43, 51) Phenelzine Irreversible nonselective MAO inhibitor. Backup drug for atypical depression. Tox: Malignant hypertension with indirect-acting sympathomimetics and tyramine, serotonin syndrome with serotonergic drugs. (30) Phenobarbital Long-acting barbiturate: used as a sedative and for tonic-clonic seizures. Facilitates GABA-mediated neuronal inhibition (by increasing duration of channel opening) and may block excitatory neurotransmitters. Partial renal clearance that can be increased by urinary alkalinization. Chronic use leads to induction of liver drug-metabolizing enzymes and ALA synthase. Tox: psychological and physiologic dependence; additive effects with other CNS depressants. (22, 24) Phenoxybenzamine Alpha-blocker prototype (nonselective): irreversible action. Phentolamine: similar with competitive action. Used in pheochromocytoma. Tox: excess hypotension; GI distress. (10) Phenytoin Anticonvulsant: used for tonic-clonic and partial seizures; blocks Na+ channels in neuronal membranes. Serum levels variable because of first-pass metabolism and nonlinear elimination kinetics. Tox: sedation, diplopia, gingival hyperplasia, hirsutism, teratogenic potential (fetal hydantoin syndrome). Drug interactions via effects on plasma protein binding or induction of hepatic metabolism. (24)
Pilocarpine Muscarinic receptor partial agonist prototype: tertiary amine alkaloid. May cause paradoxic hypertension by activating muscarinic excitatory postsynaptic potential receptors in postganglionic sympathetic neurons. Used in Sjögren's syndrome, xerostomia, glaucoma. Tox: muscarinic excess. (7) Piperacillin Extended-spectrum penicillin active against selected gram-negative bacteria, including Pseudomonas aeruginosa (synergistic with aminoglycosides). Susceptible to penicillinases unless used with tazobactam. Tox: penicillin allergy. (43) Pralidoxime Acetylcholinesterase regenerator: antidote (with atropine) for organophosphate poisoning; chemical antagonist with very high affinity for phosphorus in organophosphates. Tox: neuromuscular weakness. (8, 57, 58) Pramipexole Dopamine D3 receptor agonist in CNS (ropinirole similar): often a first-line drug in parkinsonism. Tox: postural hypotension, dyskinesias (both drugs less toxicity than the ergot bromocriptine). (28) Praziquantel Antihelminthic: important drug for trematode (fluke) and cestode (tapeworm) infections. Increases membrane permeability to Ca2+causing muscle contraction followed by paralysis. Tox: headache, dizziness, GI distress, fever; potential abortifacient. (53)
Prazosin Alpha1-selective blocker prototype: used in HTN and benign prostatic hyperplasia. Tox: first-dose orthostatic hypotension but less reflex tachycardia than nonselective blockers. Other "osins": terazosin, doxazosin. Tamsulosin similar, but used only in benign prostatic hyperplasia. (10, 11)
Prednisone Glucocorticoid prototype: potent, short acting; less mineralocorticoid activity than cortisol but more than dexamethasone, betamethasone, or triamcinolone. (20, 36, 39, 54, 55) ProbenecidUricosuric: inhibitor of renal weak acid secretion and reabsorption in proximal tubule; prolongs half-life of some antimicrobial drugs, accelerates clearance of uric acid. Used in gout. Sulfinpyrazone is similar. (36) Procainamide Group 1A antiarrhythmic drug prototype: short half-life, metabolized by N-acetyltransferase. Tox: may cause a lupus-like syndrome and torsade de pointes arrhythmia. Similar to quinidine but more cardiodepressant. (14) Propranolol Nonselective -blocker prototype: local anesthetic action but no partial agonist effect. Used in HTN, angina, arrhythmias (group 2), migraine, hyperthyroidism, tremor. Tox: asthma, AV block, HF. (8, 11, 14, 28, 38) Prostacyclin PGI2: endogenous prostaglandin vasodilator and inhibitor of platelet aggregation. An analog, epoprostenol, is used in primary pulmonary HTN. (18)
Pyrimethamine Antiprotozoal: antifolate that inhibits DHF reductase and synergistic, via sequential blockade, with sulfadiazine against Toxoplasma gondii. Folinic acid is needed to offset hematologic toxicity. (46, 52) QuinineAntimalarial: blood schizonticide; no effect on liver stages. Interferes with nucleic acid metabolism in plasmodium. Isomer of quinidine. Tox: cinchonism, GI upset. (52) RamelteonHypnotic: agonist at brain melatonin receptors; not a controlled substance. Tox: fatigue, increased prolactin and decreased testosterone. (22) Reserpine Antihypertensive (rarely used): selective inhibitor of vesicle catecholamine-H+ antiporter (VMAT); used in HTN, causes depletion of catecholamines and 5-HT from their stores. Tox: severe depression, suicide, ulcers, diarrhea. (6, 11)
Rifampin Antimicrobial: inhibitor of DNA-dependent RNA polymerase used in drug regimens for tuberculosis and the meningococcal carrier state. Tox: hepatic dysfunction, induction of liver drug-metabolizing enzymes (drug interactions), flu-like syndrome with intermittent dosing. Rifabutin similar but associated with fewer drug interactions. (47) Ritonavir Antiviral: HIV protease inhibitor (PI) used at low dose as a component of combination regimens in AIDS to inhibit metabolism of other drugs (See indinavir). Tox: implicated in many drug interactions when used as sole PI. Rosiglitazone Oral antidiabetic: thiazolidinedione stimulator of peroxisome proliferator-activator receptors (PPAR) and enhances target tissue sensitivity to insulin. Less hypoglycemia and weight gain than secretagogue antidiabetics. Tox: fluid retention, heart failure, fractures in women. Pioglitazone is similar. (41) SelegilineMAO-B inhibitor: selective inhibitor of the enzyme that metabolizes dopamine (no tyramine interactions at normal dosage). Used in Parkinson's disease. Tox: GI distress, CNS stimulation, dyskinesias, serotonin syndrome if used with selective serotonin reuptake inhibitors. Rasagiline similar and used more commonly. (28) Sildenafil Inhibits phosphodiesterase (PDE)-5, preventing breakdown of cyclic guanosine monophosphate (cGMP), which promotes vasodilation and smooth muscle relaxation. Used for erectile dysfunction and pulmonary hypertension. Tadalafil, vardenafil are similar. Tox: severe hypotension when combined with nitrates, impaired blue-green color vision. (12) Sotalol Group 3 antiarrhythmic prototype: blocks IK channels and receptors. Used for atrial and ventricular arrhythmias. Tox: torsade de pointes arrhythmias. Others in group: ibutilide, dofetilide. (14)
Spironolactone Aldosterone receptor antagonist: K+-sparing diuretic action in the collecting tubules; used in aldosteronism, HTN, and female hirsutism (androgen receptor-blocking action). Tox:hyperkalemia, gynecomastia. Eplerenone, used in HTN and heart failure, is a more selective aldosterone antagonist. (13, 15, 39, 40)
Streptogramins Antibiotics: Synercid is the combination of quinupristin and dalfopristin; bactericidal inhibitors of protein synthesis. Intravenous use for drug-resistant gram-positive cocci including MRSA (methicillin-resistant S aureus), VRE (vancomycin-resistant enterococci), and pneumococci. Tox: infusion-related pain, arthralgia, myalgia. Linezolid is another inhibitor of protein synthesis used for drug-resistant gram-positive cocci, including PRSP (penicillin-resistant S pneumoniae) strains. (44) Succinylcholine Depolarizing neuromuscular relaxant prototype: short duration (5 min) if patient has normal plasma cholinesterase (genetically determined). No antidote (compare with tubocurarine). Implicated in malignant hyperthermia. (7, 27) Sulfasalazine 5-Aminosalicylate (5-ASA) anti-inflammatory drug: used for inflammatory bowel disease (IBD) and rheumatoid arthritis. Tox: rash, GI disturbances, leukopenia. Other 5-ASA drugs used for IBD are mesalamine, balsalazide, olsalazine. (36, 59) Sumatriptan5-HT1D receptor agonist: used to abort migraine attacks. Tox: coronary vasospasm, chest pain or pressure. Six other "triptans" are currently available. (16)
Tamoxifen Selective estrogen receptor modulator (SERM): blocks estrogen receptors in breast tissue; activates endometrial receptors. Used in estrogen receptor-positive cancers, possibly prophylactic in high-risk patients. Toremifene is similar. Raloxifene, approved for osteoporosis, activates bone estrogen receptors but is an antagonist of breast and endometrial receptors. (40, 54) Terbinafine Antifungal: fungicidal inhibitor of squalene epoxidase. Most effective agent in onychomycosis, oral and topical forms. Tox: GI upsets, headache, and rash. (48) Tetracycline Antibiotic: tetracycline prototype; bacteriostatic inhibitor of protein synthesis (30S). Broad spectrum, but many resistant organisms. Used for mycoplasmal, chlamydial, rickettsial infections, chronic bronchitis, acne, cholera; a backup drug in syphilis. Tox: GI upset and superinfections, Fanconi's syndrome, photosensitivity, dental enamel dysplasia. Other tetracyclines include doxycycline (see above) and tigecycline (IV) used for multidrug-resistant nosocomial pathogens. (44) Theophylline Methylxanthine derivative found in tea; used in asthma. Bronchodilator, mild CNS stimulant. Caffeine (coffee), theobromine (cocoa) are similar. Tox:seizures. (20) Trimethoprim-sulfamethoxazole (TMP-SMZ) Antimicrobial drug combination: causes synergistic sequential blockade of folic acid synthesis. Active against many gram-negative bacteria, including Aeromonas, Enterobacter, H influenzae, Klebsiella, Moraxella, Salmonella, Serratia, and Shigella. Tox: mainly due to sulfonamide; includes hypersensitivity, myelotoxicity, kernicterus, and drug interactions caused by competition for plasma protein binding. (46, 52) Tubocurarine Nondepolarizing neuromuscular blocking agent prototype: competitive nicotinic blocker. Analogs: pancuronium, atracurium, vecuronium, and other "-curiums" and "-oniums." Tox: respiratory paralysis. Releases histamine and may cause hypotension, therefore rarely used. Antidote: cholinesterase inhibitor, for examples, neostigmine. (8, 26) Tyramine Indirect-acting sympathomimetic prototype: releases or displaces norepinephrine from stores in nerve endings. Presence in certain foods may cause potentially lethal hypertensive responses in patients taking MAO inhibitors. (6, 27) Valproic acid Anticonvulsant: primary drug in absence, clonic-tonic, and myoclonic seizure states. Also used commonly for bipolar disorder. Tox: GI distress, hepatic necrosis (rare), teratogenic (spina bifida), inhibits drug metabolism. (24, 29) Vancomycin Glycopeptide bactericidal antibiotic: inhibits synthesis of cell wall precursor molecules. A drug of choice for methicillin-resistant staphylococci and effective in antibiotic-induced colitis. Dose reduction required in renal impairment (or hemodialysis). Tox: ototoxicity, hypersensitivity, renal dysfunction (rare). (43, 51) Verapamil Calcium channel blocker prototype: blocks L-type channels; cardiac depressant and vasodilator; used in HTN, angina, and arrhythmias (group 4). Tox: AV block, HF, constipation. Diltiazem, like verapamil, has more depressant effect on heart than dihydropyridines (eg, nifedipine). (11, 12, 14) Vincristine Antineoplastic: cell cycle (M phase)-specific plant alkaloid; inhibits mitotic spindle formation. Tox: peripheral neuropathy. Vinblastine, a congener, causes myelosuppression. (54) Warfarin Oral anticoagulant prototype: causes synthesis of nonfunctional versions of the vitamin K-dependent clotting factors (II, VII, IX, X). Tox: bleeding, teratogenic. Antidote: vitamin K, fresh plasma. (34) Zidovudine (ZDV) Antiviral: prototype NRTI used in combinations for HIV infections and in prophylaxis for needlesticks and vertical transmission. Tox: severe myelosuppression. Other NRTIs: abacavir, didanosine (ddI), lamivudine (3TC), stavudine (d4T), and zalcitabine (ddC). (49) Zolpidem Nonbenzodiazepine hypnotic: acts via the BZ1 receptor subtype and is reversed by flumazenil; less amnesia and muscle relaxation and lower dependence liability than benzodiazepines. Zaleplon and eszopiclone are similar. (22)