Cidofovir

Indications

Cidofovir is used for: Cytomegaloviral retinitis in AIDS patients

Adult Dose

Intravenous Cytomegaloviral retinitis in AIDS patients Adult: Induction: 5 mg/kg by infusion over 1 hr once wkly for 2 consecutive wk. Maintenance: 5 mg/kg once every 2 wk, starting 2 wk after completion of induction treatment. Administer w/ oral probenecid 2 g, 3 hr prior to each cidofovir dose, further doses of 1 g at 2 and 8 hr after completion of infusion. Hydration: Infuse 1 L normal saline over 1-2 hr immediately before cidofovir infusion; if patient can tolerate additional water load, a 2nd liter may be given over 1-3 hr at the start of or immediately following infusion.

Child Dose

Renal Dose

Renal impairment: Contraindicated.

Administration

Contra Indications

Hypersensitivity to cidofovir and probenecid or other sulfur-containing medicines. Direct intraocular inj. Renal impairment (serum creatinine >1.5 mg/dL, CrCl <55 mL/min, or urine protein >100 mg/dL [>2+ proteinuria]). Lactation. Concomitant use or w/in 7 days of treatment w/ potentially nephrotoxic drugs.

Precautions

Hepatic impairment. Pregnancy. Monitoring Parameters Monitor for renal function (serum creatinine and urine protein) w/in 48 hr prior each dose and WBC including neutrophil count prior to each dose; signs/symptoms of uveitis/iritis, metabolic acidosis.

Pregnancy-Lactation

Pregnancy Category: C Lactation: It is not known whether cidofovir is excreted in milk. It should not be administered to nursing mothers.

Interactions

Increased risk of adverse inflammatory effects when administered w/ 2-4 wk of intravitreal fomivirsen. Potentially Fatal: Increased risk of nephrotoxicity w/ potentially nephrotoxic drugs (e.g. aminoglycosides, amphotericin B, foscarnet, IV pentamidine, vancomyicn, NSAIDs).

Adverse Effects

Side effects of Cidofovir : Nephrotoxicity, neutropenia, nausea, diarrhoea, headache, vomiting, fever, chills, asthenia, skin rash, dyspnoea, alopecia, ocular hypotony; iritis or uveitis. May cause hypospermia. Potentially Fatal: Acute renal failure, metabolic acidosis w/ hepatic impairment and pancreatitis.

Mechanism of Action

Cidofovir is a purine nucleotide analog that is active against herpesviruses and certain other viruses. It is converted to its active intracellular metabolite, cidovir diphosphate, and supresses CMV replication by selectively inhibiting viral DNA synthesis. Also, it reduces the rate of viral DNA synthesis by incorporation into growing viral DNA chains.