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.
Renal Impairment
Contraindicated.
Reconstitution
Dilute dose in normal saline 100mL prior to infusion.
Contraindications
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.
Special Precautions
Hepatic impairment. Pregnancy.
Adverse Reactions
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.
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.
Drug 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).
Action
Description: 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. Pharmacokinetics: Distribution: Volume of distribution: 0.41 L/kg. Plasma protein binding: <6%. Metabolism: Minimally metabolised via intracellular phosphorylation by cellular kinases to cidofovir diphosphate. Excretion: Via urine (70-85% as unchanged drug). Elimination half-life: Approx 2.6 hr.
Chemical Structure
Cidofovir Source: National Center for Biotechnology Information. PubChem Database. Cidofovir, CID=60613, https://pubchem.ncbi.nlm.nih.gov/compound/Cidofovir (accessed on Jan. 21, 2020)
J05AB12 - cidofovir ; Belongs to the class of nucleosides and nucleotides excluding reverse transcriptase inhibitors. Used in the systemic treatment of viral infections.
References
Anon. Cidofovir. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 01/06/2016.Buckingham R (ed). Cidofovir. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 01/06/2016.Cidofovir Diehydrate Injection, Solution (Heritage Pharmaceuticals, Inc.). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/. Accessed 01/06/2016.McEvoy GK, Snow EK, Miller J et al (eds). Cidofovir. AHFS Drug Information (AHFS DI) [online]. American Society of Health-System Pharmacists (ASHP). https://www.medicinescomplete.com. Accessed 01/06/2016.