VALACYCLOVIR (VALTREX, GENERIC)
USES: *Herpes zoster; genital herpes; herpes labialis.*
ACTIONS: Prodrug of acyclovir; ↓ viral DNA replication. Spectrum: Herpes simplex I & II.
DOSE: Zoster: 1 g PO TID × 7 days. Genital herpes (initial episode): 1 g BID × 7–10 days, (recurrent) 500 mg PO BID × 3 days. Herpes prophylaxis: 500–1,000 mg/d. Herpes labialis: 2 g PO q12h × 1 day ↓ w/ renal failure.
W/P: [B, +] ↑ CNS effects in elderly.
DISP: Caplets 500, 1,000 mg; tab 500, 1,000 mg.
SE: Headache, GI upset, ↑ LFTs, dizziness, pruritus, photophobia.
VALRUBICIN (VALSTAR)
USES: *Intravesical therapy of BCG-refractory bladder CIS in patients for whom immediate cystectomy would be associated with unacceptable morbidity or mortality.*
ACTIONS: An anthracycline; alkylating agent.
DOSE: 800 mg intravesically 1 × wk for 6 wk (4 vials diluted in 55 mL NS, total volume of 75 mL).
W/P: [C, -] do not administer with perforated bladder.
CI: Hypersensitivity to anthracyclines or polyoxyl castor oil, UTI, bladder capacity <75 mL.
DISP: 5 mL single-use vials (200 mg/5mL).
SE: Frequency, dysuria, urgency, spasm, hematuria, pain, incontinence.
NOTES: monitor closely for disease recurrence or progression; if there is not a complete response of CIS to treatment after 3 mo or if CIS recurs, cystectomy must be reconsidered. Procedures for proper handling and disposal of anticancer drugs should be used. Spills should be cleaned up with undiluted chlorine bleach.
VANCOMYCIN (VANCOCIN, GENERIC)
USES: *Serious MRSA infections; enterococcal infections; PO Treat of S. aureus and C. difficile pseudomembranous colitis.*
ACTIONS: ↓ Cell wall synth. Spectrum: gram(+) bacteria & some anaerobes (includes MRSA, Staphylococcus, Enterococcus, Streptococcus sp, C. difficile).
DOSE:
Adults: 15–20 mg/kg IV q8–48h based on CrCl, 15–20 mg/kg/dose; C. difficile: 125–500 mg PO q6h × 7 days.
Peds: 40–60 mg/kg/d IV in ÷ doses q6–12 h; C. difficile: 40 mg/kg/d PO in ÷ 3–4 doses × 7–10 days.
W/P: [B oral + C Inj, -].
CI: Component allergy; avoid in Hx hearing loss.
DISP: Caps 125, 250 mg; powder for Inj.
SE: Oto/nephrotoxic, GI upset (PO).
NOTES: Not absorbed PO, effect in gut only; give IV slowly (over 1–3 hr) to prevent “red-man syndrome” (flushing of head/neck/upper torso); IV product used PO for colitis. Levels: Trough: <0.5 hr before next dose; Therapeutic: Trough: 10–20 μg/mL; Trough: 15–20 μg/mL. Half-life: 6–8 hr; peak monitoring is not rec (toxic >80 μg/mL).
VARDENAFIL (LEVITRA, STAXYN, GENERIC)
USES: *Erectile dysfunction.*
ACTIONS: PDE5 inhibitor, increases cGMP and NO levels; relaxes smooth muscles, dilates cavernosal arteries; onset 15–60 min, duration 2–8 hr.
DOSE: Levitra 10 mg PO 60 min before sexual activity; titrate; max. × 1 = 20 mg; 2.5 mg w/ CYP3A4 inhibitor; Staxyn 1 (10 mg ODT) 60 min before sex, max. 1×/d.
W/P: [B, −] w/ CV, hepatic, or renal disease or if sex activity not advisable; potentiate the hypotensive effects of nitrates, α-blockers, and antihypertensives.
CI: w/ Nitrates.
DISP: Levitra Tabs 2.5, 5, 10, 20 mg tabs; Stayxn 10 mg ODT (contains phenylalanine).
SE: ↑ QT interval ↓ BP, headache, dyspepsia, priapism, flushing, rhinitis, sinusitis, flu syndrome, sudden ↓/loss of hearing, tinnitus, NIAON.
NOTES: Do not use w/ type 1A or type 3 antiarrhythmics or w/ long QT syndrome; concomitant α-blockers may cause ↓ BP; transient global amnesia reports; place Staxyn on tongue to disintegrate w/o liquids; ODT not interchangeable to oral pill; gets higher levels.
VERAPAMIL (CALAN, COVERA HS, ISOPTIN, VERELAN, GENERIC)
USES: *Angina, HTN, PSVT, AF, atrial flutter*, migraine prophylaxis, hypertrophic cardiomyopathy, bipolar disease, Peyronie disease.
ACTIONS: Calcium channel blocker.
DOSE:
Adults: Arrhythmias: 2nd line for PSVT w/ narrow QRS complex & adequate BP 2.5–10 mg IV over 1–2 min; repeat 5–10 mg in 15–30 min PRN (30 mg max.). Angina: 80–120 mg PO TID, ↑ 480 mg/24 h max. HTN: 80–180 mg PO TID or SR tabs 120–240 mg PO daily to 240 mg BID.
Peds: <1 yr: 0.1–0.2 mg/kg IV over 2 min (may repeat in 30 min). 1–16 yr: 0.1–0.3 mg/kg IV over 2 min (may repeat in 30 min); 5 mg max. PO: 3–4 mg/kg/d PO ÷ in 3 doses, max. 8 mg/kg/d up to 480 mg/d. >5 yr: 80 mg q6–8h; ↓ in renal/hepatic impairment.
W/P: [C, +] Amiodarone/β-blockers/flecainide can cause ↓ HR; statins, midazolam, tacrolimus, theophylline levels may be ↑; use w/ clonidine may cause severe ↓ HR w/ elderly pts.
CI: EF <30%, severe LV dysfunction, BP <90 mm Hg, SSS, 2nd-, 3rd-AV block AF/atrial flutter w/ bypass tract.
DISP: Calan SR: Caps 120, 180, 240 mg; Verelan SR: Caps 120, 180, 240, 360 mg; Verelan PM: Caps (ER) 100, 200, 300 mg; Calan: Tabs 80, 120 mg; Isoptin SR 24-hr 120, 180, 240 mg; Inj 2.5 mg/mL.
SE: Gingival hyperplasia, constipation, ↓ BP, bronchospasm, HR or conduction disturbances; edema; ↓ BP and bradyarrhythmias taken w/ telithromycin.
NOTES: topical use reported in Peyronie disease.
VINBLASTINE (GENERIC)
WARNING: Chemotherapeutic agent; handle w/ caution; only individuals experienced in use of vinblastine should administer.
USES: *Hodgkin’s disease, non-Hodgkin’s malignant lymphomas, rhabdomyosarcoma, neuroblastoma, Wilms’ tumor, acute leukemia.*
ACTIONS: ↓ Microtubule assembly.
DOSE: 0.1–0.5 mg/kg/wk (4–20 mg/m2) (based on specific protocol); ↓ in hepatic failure.
W/P: [D, ?].
CI: Granulocytopenia, bacterial infection.
DISP: Inj 1 mg/mL in 10-mg vial.
SE: ↓ BM (especially leukopenia), N/V, constipation, neurotox, alopecia, rash, myalgia, tumor pain.
NOTES: Use can be fatal.
VINCRISTINE (MARQIBO, GENERIC)
WARNING: Chemotherapeutic agent; handle w/ caution; fatal if administered IT; IV only; administration by individuals experienced in use of vincristine only; severe w/ extrav.
USES: *ALL, breast & small-cell lung cancer, sarcoma (eg, Ewing tumor, rhabdomyosarcoma), Wilms tumor, Hodgkin disease & NHLs, neuroblastoma, multiple myeloma.*
ACTIONS: Promotes disassembly of mitotic spindle, causing metaphase arrest, vinca alkaloid.
DOSE: 0.4–1.4 mg/m2 (single doses 2 mg/max.); ↓ in hepatic failure.
W/P: [D, −].
CI: Charcot–Marie–Tooth syndrome
DISP: Inj 1 mg/mL.
SE: Neurotox commonly dose limiting, jaw pain (trigeminal neuralgia), fever, fatigue, anorexia, constipation & paralytic ileus, bladder atony; no sig ↓ BM w/ standard doses; tissue necrosis w/ extrav; myelosuppression.