Ganciclovir

Ganciclovir is used for: CMV retinitis, Pneumonitis, Cytomegaloviral infections

Ophthalmic Herpes simplex keratitis Adult: As 0.15% gel: Apply 1 drop in the inferior conjunctival sac of the affected eye 5 times daily (approx 3 hrly while awake) until corneal healing occurs. Maintenance: 1 drop tid for 7 days after healing. Intravenous CMV Retinitis Initial: 5 mg/kg IV q12hr, over 1 hr x14-21d Maintenance 5 mg/kg IV qD OR 6 mg/kg IV qD for 5 d/week CMV Prevention in Transplant Recipients Induction: 10 mg/kg/d div q12hr IV x7-14 d Maintenance 5 mg/kg IV qD x100-120 d after transplant OR 6 mg/kg IV qD for 5 d/week x100-120 d after transplant CMV Prevention in HIV Infected 5-6 mg/kg 5-7x/week IV (recurrence)

Ophthalmic Herpes simplex keratitis <2 years: Safety and efficacy not established 2 years or older: Apply 1 drop in the inferior conjunctival sac of the affected eye 5 times daily (approx 3 hrly while awake) until corneal healing occurs. Maintenance: 1 drop tid for 7 days after healing.

Renal Impairment (IV Induction) CrCl 50-69 mL/min: 2.5 mg/kg IV q12hr CrCl 25-49 mL/min: 2.5 mg/kg IV qD CrCl <25 mL/min: 1.25 mg/kg IV qD Renal impairment: Dialysis patients: 1.25 mg/kg for induction or 0.625 mg/kg for maintenance, to be given post dialysis on days when dialysis is performed. CrCl (ml/min) Dosage Recommendation 10-24 1.25 mg/kg/day for induction, then 0.625 mg/kg/day for maintenance. 25-49 2.5 mg/kg/day for induction, then 1.25 mg/kg/day for maintenance. 50-69 2.5 mg/kg 12 hrly for induction, then 2.5 mg/kg/day for maintenance.

Reconstitution: Add 10 mL of sterile water for inj to the vial labelled as containing 500 mg to provide a soln containing 50 mg/mL. Withdraw the appropriate dose of reconstituted soln from the vial and further dilute in 50-250 (usually 100) mL of a compatible IV infusion soln.

Hypersensitivity; absolute neutrophil count <500 cells/mm3; platelet count <25,000/mm3; pregnancy, lactation. Not to be used as a bolus inj.

Renal impairment; preexisting cytopenias or history of cytopenic reactions to drugs; child; contraceptive precautions to be followed during and at least 90 days thereafter; care in administering only into veins with good blood flow. Avoid contact with the skin and eyes. Maintain adequate hydration during infusion. Monitor WBC and platelet counts regularly during treatment. Eye examinations should be conducted at least once every 4-6 wk during treatment for CMV retinitis. Lactation: excretion in milk unknown; use with caution

Pregnancy Placental transfer of ganciclovir has been shown to occur based on ex vivo experiments with human placenta and in at least 1 case report in a pregnant woman; however, no adequate human data are available to establish whether ganciclovir poses a risk to pregnancy outcomes In animal studies, ganciclovir caused maternal and fetal toxicity and embryo-fetal mortality in pregnant mice and rabbits as well as teratogenicity in rabbits at exposures 2 times the exposure at the recommended human dose (RHD) Disease-associated maternal and/or embryo-fetal risk Most maternal CMV infections are asymptomatic or they may be associated with a self-limited mononucleosis-like syndrome; however, in immunocompromised patients, CMV infections may be symptomatic and may result in significant maternal morbidity and mortality CMV fetal transmission results from maternal viremia and transplacental infection Perinatal infection can also occur from exposure of the neonate to CMV shedding in the genital tract ~10% of children with congenital CMV infection are symptomatic at birth Mortality in symptomatic infants is ~10% and ~50-90% of symptomatic surviving newborns experience significant morbidity, including mental retardation, sensorineural hearing loss, microcephaly, seizures, and other medical problems Risk of congenital CMV infection resulting from primary maternal CMV infection may be higher and of greater severity than that resulting from maternal reactivation of CMV infection Contraception Test for pregnancy in females of reproductive potential before initiating treatment Females: Because of ganciclovir’s mutagenic and teratogenic potential, use effective contraception during treatment and for at least 30 days following treatment Males: Because of ganciclovir’s mutagenic and teratogenic potential, use barrier contraception during treatment and for at least 90 days following treatment Infertility Based on animal data and limited human data, may cause temporary or permanent inhibition of spermatogenesis in males, and may cause suppression of fertility in females at recommended human dose (RHD); advise patients that fertility may be impaired with use Lactation No data are available regarding the presence of ganciclovir in human milk, the effects on the breastfed infant, or the effects on milk production Ganciclovir was present in milk in lactating rats following administration Breastfeeding is not recommended during treatment owing to the potential for serious adverse reactions in nursing infants

Increased risk of haematologic toxicity w/ zidovudine. May increase serum levels of didanosine. Increased serum concentration w/ probenecid and other drugs that inhibit renal tubular secretion and resorption. Use of IV ganciclovir w/ oral mycophenolate mofetil may result in increased plasma concentrations of both drugs due to competition for renal tubular secretion. Concomitant use w/ immunosuppressive agents (e.g. azathioprine, ciclosporin, corticosteroids) may result in excessive suppression of bone marrow or the immune system. Generalised seizure may occur when taken w/ imipenem and cilastatin. Concurrent use w/ drugs that inhibit replication of rapidly dividing cells (e.g. dapsone, pentamidine, pyrimethamine, flucytosine, cytotoxic antineoplastic agents, amphotericin B, co-trimoxazole, other nucleoside analogues) may result in additive toxicity.

Side effects of Ganciclovir : Opthalmic >10% Blurred vision (60%), Eye irritation (20%) 1-10% Punctate keratitis (5%), Conjunctival hyperemia (5%) Intravenous >10% Neutropenia w/ ANC <1000/cu.mm (25-50%), Thrombocytopenia (20%) 1-10% Abnl LFTs, Anemia, Confusion, Headache, Nausea/vomiting, Neuropathy, Paresthesia, Pruritus, Retinal detachment, Rash, Sepsis, Weakness

Ganciclovir is a synthetic guanine nucleoside analogue with activity against cytomegalovirus (CMV). It competitively inhibits the binding of deoxyguanosine triphosphate to DNA polymerase, thus inhibiting viral DNA synthesis.