GABAPENTIN (NEURONTIN, GENERIC)
USES: *Postherpetic neuralgia (PHN); adjunct in partial seizures*; chronic pain synds.
ACTIONS: Anticonvulsant; GABA analog.
DOSE:
Adults & Peds: > 12 yr: Anticonvulsant: 300 mg PO TID, ↑ max. 3,600 mg/d. PHN: 300 mg day 1, 300 mg BID day 2, 300 mg TID day 3, titrate (1,800–3,600 mg/d);
Peds: 3–12 yr: 0–15 mg/kg/d ÷ TID, ↑ over 3 days, 3–4 yr: 40 mg/kg/d given TID. ≥5 yr: 25–35 mg/kg/d ÷ TID, 50 mg/kg/d max. ↓ w/ renal impairment.
W/P: [C, ?] Use in peds 3–12 yr w/ epilepsy may ↑ CNS-related adverse events.
CI: Component sensitivity.
DISP: Caps 100, 300, 400 mg; soln 250 mg/5 mL; scored tab 600, 800 mg.
SE: Somnolence, dizziness, ataxia, fatigue.
NOTES: Not necessary to monitor levels; taper ↑ or ↓ over 1 wk.
GANCICLOVIR (CYTOVENE, VITRASERT, GENERIC)
Toxicity includes granulocytopenia, anemia and thrombocytopenia. In animal studies ganciclovir was carcinogenic, teratogenic and caused aspermatogenesis. Ganciclovir for injection indicated only in the treatment of CMV retinitis in immunocompromised patients and to prevent CMV at risk transplant patients.
USES: *Treat & prevent CMV retinitis, prevent CMV disease* in transplant recipients.
ACTIONS: ↓ Viral DNA synth.
DOSE:
Adults & Peds: IV: 5 mg/kg IV q12h for 14–21 days, then maint 5 mg/kg/d IV × 7 d/ wk or 6 mg/kg/d IV × 5 d/wk.
Adults: PO: Following induction, 1,000 mg PO TID. Prevention: 1,000 mg PO TID; w/ food; ↓ in renal impairment.
W/P: [C, −] ↑ Effect w/ immunosuppressives, imipenem/cilastatin, zidovudine, didanosine, other nephrotoxic Treat.
CI: ANC <500 cells/mm3, plt <25,000 cells/mm3, intravitreal implant.
DISP: Caps 250, 500 mg; Inj 500 mg, ocular implant 4.5 mg.
SE: Granulocytopenia & thrombocytopenia, fever, rash, GI upset.
NOTES: Not a cure for CMV; handle Inj w/ cytotoxic cautions; no systemic benefit w/ implant.
GEMCITABINE (GEMZAR, GENERIC)
USES: *Pancreatic cancer (single agent), breast cancer w/ paclitaxel, NSCLC w/ cisplatin, ovarian cancer w/ carboplatin*, gastric cancer, urothelial carcinoma (systemic and intravesical).
ACTIONS: Antimetabolite; nucleoside metabolic inhibitor; ↓ ribonucleotide reductase; produces false nucleotide base-inhibiting DNA synth.
DOSE: 1,000–1,250 mg/ m2 over 30 min–1 hr IV Inf/wk × 3–4 wk or 6–8 wk; modify dose based on hematologic function (per protocol).
W/P: [D, ?/−] Hemolytic uremic syndrome (HUS), pulmonary toxicity, embryofet al toxicity, ↑ radiation therapy toxicity, capillary leak syndrome, posterior reversible encephalopathy syndrome (PRES).
CI: Pregnancy.
DISP: Inj 200 mg, 1 g.
SE: ↓ BM, N/V/diarrhea, drug fever, skin rash.
NOTES: Reconstituted soln 38 mg/mL; monitor hepatic/renal function; intravesical regimen described: 40 mg/mL (2,000 mg in 50 mL saline) weekly.
GENTAMICIN, INJECTABLE (GENERIC)
USES: *Septicemia, serious bacterial infection of CNS, urinary tract, resp tract, GI tract, including peritonitis, skin, bone, soft tissue, including burns; severe infection P. aeruginosa w/ carbenicillin; group D streptococci endocarditis w/ PCN-type drug; serious staphylococcal infections, but not the antibiotic of 1st choice; mixed infection w/ staphylococci and gram(−).*
ACTIONS: Aminoglycoside, bactericidal; ↓ protein synth. Spectrum: gram(−) (not Neisseria, Legionella, Acinetobacter); weaker gram(+) but synergy w/ PCNs.
DOSE:
Adults: Standard: 1–2 mg/kg IV q8–12h or daily dosing 4–7 mg/kg q24h IV. Gram(+) Synergy: 1 mg/kg q8h.
Peds: Infants <7 days <1,200 g: 2.5 mg/kg/dose q18–24h. Infants >1,200 g: 2.5 mg/kg/dose q12–18h. Infants >7 days: 2.5 mg/kg/dose IV q8–12h. Children: 2.5 mg/kg/d IV q8h; ↓ w/ renal insufficiency; if obese, dose based on IBW.
W/P: [C, +/−] Avoid other nephrotoxics.
CI: Aminoglycoside sensitivity.
DISP: Premixed Inf 40, 60, 70, 80, 90, 100, 120 mg; ADD-Vantage Inj vials 10 mg/mL; Inj 40 mg/mL; IT preservative-free 2 mg/mL.
SE: Nephro/oto/neurotox.
NOTES: Follow CrCl, SCr, & serum conc for dose adjustments; use IBW to dose (use adjusted if obese >30% IBW); OK to use intraperitoneal for peritoneal dialysis-related infections. Levels: Peak: 30 min after Inf; Trough: <0.5 hr before next dose; Therapeutic: Peak: 5–8 μg/mL, Trough: <2 μg/mL, if >2 μg/mL associated w/ renal tox.
GOSERELIN (ZOLADEX)
USES: *Used with flutamide for the management of locally confined carcinoma of the prostate and palliative treatment of advanced carcinoma of the prostate, *endometriosis, breast cancer.
ACTIONS: LHRH agonist, transient ↑ then ↓ in LH, w/ ↓ testosterone.
DOSE: 3.6 mg SQ (implant) q28d or.10.8 mg SQ q3mo; usually upper abdominal wall.
W/P: [X, −].
CI: Pregnancy, breast-feeding, 10.8-mg implant not for women.
DISP: SQ implant 3.6 (1 mo), 10.8 mg (3 mo).
SE: Hot flashes, ↓ libido, gynecomastia, & transient exacerbation of cancer-related bone pain (“flare reaction” 7–10 days after 1st dose).
NOTES: Inject SQ into fat in abdominal wall; do not aspirate; females must use contraception.