Names and pronunciation
(gan-sye′kloe-vir) Zirgan
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Drug reference
(gan-sye′kloe-vir) Zirgan
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Func. class.: Antiviral
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Chem. class.: Synthetic nucleoside analog
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ACTION: Inhibits replication of herpes- viruses; competitively inhibits human CMV DNA polymerase and is incorporated, resulting in termination of DNA elongation
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USES: Cytomegalovirus (CMV) retini- tis in immunocompromised persons, including those with AIDS, after indirect ophthalmoscopy confirms diagnosis; prophylaxis for CMV in transplantation; ophthalmic: acute herpes keratitis
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CONTRAINDICATIONS: Hyper- sensitivity to acyclovir, ganciclovir
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Black Box Warning: Absolute neutro- phil count <500/mm3, platelet count <25,000/mm3 (intravitreal) Precautions: breastfeeding, children <6 mo, geriatric patients, preexisting cytopenias, renal function impairment, radiation therapy, hypersensitivity to famciclovir, penciclovir, valacyclovir, valganciclovir Black Box Warning: Secondary malig- nancy, bone marrow suppression, ane- mia, infertility, neutropenia, pregnancy, male-mediated teratogenicity Black Box Warning: Secondary malig- nancy: avoid direct contact with powder in caps/solution; if skin contact occurs, wash thoroughly with soap and water; do not get in the eyes • CMV retinitis: Culture of blood, urine, and throat may be taken, CMV is not confirmed by this method; ophthalmic exam confirms diagnosis, these exams should be done baseline, weekly (induc- tion), q2wk (maintenance) • Infection: Increased temperature, sore throat, chills, fever; report to prescriber Black Box Warning: Leukopenia/ neutropenia/thrombocytopenia: CBC, WBCs, platelets q2days during 2×/day dosing and then q1wk for leukopenia with daily WBC count in patients with pri- or leukopenia with other nucleoside ana- logs or for whom leukopenia counts are <1000 cells/mm3 at start of treatment • Serum creatinine or CCr ≥q2wk, BUN; LFTs; ophthalmic exam • For seizures, dysrhythmias • Infection: Assess for flulike symptoms/ fever, sore throat, coughing • Bleeding: Assess for bleeding, throm- bocytopenia, check gums, urine, emesis, avoid rectal temperature, vein punctures • Pregnancy/breastfeeding: Not to be used in pregnancy, confirm by pregnancy test Black Box Warning: Pregnancy: use contraception during treatment (males/ females) and that infertility may occur; males should use barrier contraception for 90 days after treatment; may cause reversible infertility at lower doses, irre- versible infertility at higher doses; not to breastfeed (IV) • To report infection: fever, chills, sore throat; blood dyscrasias: bruising, bleed- ing, petechiae; to avoid crowds, persons with respiratory infections • To report itching, redness or eye pain (ophthalmic treatment) See Appendix B
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SIDE EFFECTS CNS: Fever, chills, coma, confusion, abnormal thoughts, dizziness, bizarre dreams, headache, psychosis, tremors, G somnolence, paresthesia, weak- ness, seizures, peripheral neuropathy CV: Dysrhythmia, hypo/hypertension EENT: Retinal detachment in CMV retini- tis, ocular hypertension, ocular pain, conjunctival scarring, cataracts GI: Abnormal LFTs, nausea, vomiting, anorexia, diarrhea, abdominal pain, hemorrhage, perforation, pancreatitis GU: Hematuria, increased creatinine, BUN, infertility, decreased sperm count HEMA: Granulocytopenia, thrombocyto- penia, irreversible neutropenia, anemia, eosinophilia, pancytopenia INTEG: Rash, alopecia, pruritus, urti- caria, pain at site, phlebitis RESP: Dyspnea, pneumonia
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INTERACTIONS Increase: severe granulocytopenia— zidovudine, antineoplastics, radiation; do not give together Increase: ganciclovir toxicity—adriamycin, amphotericin B, cycloSPORINE, dapsone, DOXOrubicin, flucytosine, pentamidine, pro- benecid, trimethoprim-sulfamethoxazole combinations, vinBLAStine, vinCRIStine, other nucleoside analogs, mycophenolate, tenofo- vir, tacrolimus, aminoglycosides, NSAIDs Increase: seizures—imipenem/cilastatin Increase: didanosine effect—didanosine Drug/Lab Test Increase: LFTs, creatinine, GCT Decrease: Hb, WBC, platelets, neutro- phils, granulocytes NURSING CONSIDERATIONS
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DOSAGE AND ROUTES Prevention of CMV • Adult/adolescent: IV 5 mg/kg/dose over 1 hr q12hr × 1-2 wk, then 5 mg/kg/ day 7 day/wk, or 6 mg/kg/day × 5 days/wk Acute herpes keratitis • Adult/adolescent/child ≥2 yr: OPHTH 1 drop in affected eye 5 times daily until ulcer heals, then 1 drop tid × 7 days Renal dose • Adult: IV CCr 50-69 mL/min, reduce to 2.5 mg/kg q12hr (induction), 2.5 mg/kg q24hr (maintenance); IV CCr 25-49 mL/ min, reduce to 2.5 mg/kg (induction); 1.25 mg/kg q24hr (maintenance); IV CCr 10-24 mL/min, reduce to 1.25 mg/kg q24hr (in- duction); 0.625 mg/kg q24hr (mainte- nance); IV CCr <10 mL/min, reduce to 1.25 mg/kg 3×/wk after hemodialysis (induc- tion); 0.625 mg/kg 3×/wk after hemodialy- sis (maintenance)
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Available forms: Powder for inj 500 mg/vial; ophth gel 0.15% (Zirgan)
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Administer: IV route • Mixed in biologic cabinet using gown, gloves, mask; use cytotoxic handling pro- cedures; do not use if particulate matter is present Intermittent IV INFUSION route • IV after reconstituting 500 mg/10 mL sterile water for inj (50 mg/mL), don't use bacteriostatic water with parabens; shake; further dilute in 50-250 mL D5W, 0.9% NaCl, LR, Ringer’s and run over 1 hr; use infusion pump, in-line filter, flush line well before and after product • Do not give by bolus IV, IM, SUBCUT inj • Use reconstituted sol within 24 hr; do not refrigerate or freeze compatibilities: Allopurinol, Y-site amphotericin B cholesteryl, CISplatin, cyclophosphamide, DOXOrubicin lipo- some, enalaprilat, etoposide, filgrastim, fluconazole, gatifloxacin, granisetron, linezolid, melphalan, methotrexate, PACLitaxel, propofol, remifentanil, tacro- limus, teniposide, thiotepa
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Assess:
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Evaluate: • Therapeutic response: decreased symptoms or prevention of CMV retinitis in transplant patients (if needed)
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Patient and caregiver information: • Not to wear contact lenses while using gel • That product does not cure condition; that regular blood tests, ophthalmologic exams are necessary • That major toxicities may necessitate discontinuing product
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PHARMACOKINETICS Half-life 3-4½ hr (IV); excreted by kid- neys (unchanged); crosses blood-brain barrier, CSF, onset rapid, peak infusions end, duration up to 24 hr
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• Adult/adolescent: IV 5 mg/kg/dose over 1 hr q12hr × 1-2 wk, then 5 mg/kg/ day 7 day/wk, or 6 mg/kg/day × 5 days/wk Acute herpes keratitis
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• Adult/adolescent/child ≥2 yr: OPHTH 1 drop in affected eye 5 times daily until ulcer heals, then 1 drop tid × 7 days Renal dose
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• Adult: IV CCr 50-69 mL/min, reduce to 2.5 mg/kg q12hr (induction), 2.5 mg/kg q24hr (maintenance); IV CCr 25-49 mL/ min, reduce to 2.5 mg/kg (induction); 1.25 mg/kg q24hr (maintenance); IV CCr 10-24 mL/min, reduce to 1.25 mg/kg q24hr (in- duction); 0.625 mg/kg q24hr (mainte- nance); IV CCr <10 mL/min, reduce to 1.25 mg/kg 3×/wk after hemodialysis (induc- tion); 0.625 mg/kg 3×/wk after hemodialy- sis (maintenance)
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