Nurses Compass
Drug Guide
Cidofovir
Classification
Therapeutic: Antiviral
Pharmacological: Nucleotide Analog
FDA Approved Indications
- Treatment of cytomegalovirus (CMV) retinitis in patients with AIDS
Mechanism of Action
Cidofovir inhibits viral DNA polymerase, resulting in DNA chain termination and inhibition of viral DNA synthesis.
Dosage and Administration
Adult: 5 mg/kg IV once weekly for 2 weeks, then every 2 weeks; prehydration with saline and probenecid recommended.
Pediatric: Use is off-label; dosing based on weight and clinical judgment.
Geriatric: Adjust dose carefully, monitor renal function closely.
Renal Impairment: Reduce dose or extend dosing interval; prehydration and probenecid used to reduce nephrotoxicity.
Hepatic Impairment: No specific adjustment; monitor closely.
Pharmacokinetics
Absorption: Administered intravenously; not absorbed orally.
Distribution: Widely distributed, concentrates in renal cortex.
Metabolism: Not metabolized; excreted unchanged.
Excretion: Primarily through kidneys via glomerular filtration and active tubular secretion.
Half Life: approximately 2.6 hours in patients with normal renal function.
Contraindications
- Hypersensitivity to cidofovir or probenecid.
Precautions
- Renal impairment, pre-existing kidney disease, prior aminoglycoside use, dehydration.
Adverse Reactions - Common
- Nephrotoxicity (Common)
- Neutropenia (Less common)
- Ocular complications (Rare)
Adverse Reactions - Serious
- Acute renal failure (Serious)
- Severe neutropenia (Serious)
- Fanconi syndrome (renal tubular dysfunction) (Serious)
Drug-Drug Interactions
- Nephrotoxic drugs (e.g., aminoglycosides, NSAIDs), which increase risk of renal damage.
Drug-Food Interactions
N/ADrug-Herb Interactions
N/ANursing Implications
Assessment: Monitor renal function (serum creatinine, urine tests) before and during therapy. Assess for signs of neutropenia and ocular toxicity.
Diagnoses:
- Risk for nephrotoxicity
- Risk for infection due to neutropenia
Implementation: Ensure adequate hydration, administer probenecid 2 g orally 2 hours before and 1 hour after cidofovir infusion, monitor lab values, educate patient on renal and ocular symptoms.
Evaluation: Regularly evaluate renal function tests, blood counts, and ocular health.
Patient/Family Teaching
- Report signs of kidney problems (e.g., decreased urine output, swelling).
- Avoid dehydration.
- Understand the importance of follow-up labs and ocular exams.
- Inform about potential side effects and when to seek medical attention.
Special Considerations
Black Box Warnings:
- Nephrotoxicity, which can be severe and lead to kidney failure.
Genetic Factors: None currently identified.
Lab Test Interference: May increase serum creatinine and blood urea nitrogen (BUN).
Overdose Management
Signs/Symptoms: Severe kidney damage, neutropenia.
Treatment: Supportive; dialysis may be necessary for renal failure.
Storage and Handling
Storage: Store at room temperature away from moisture and heat.
Stability: Stable when stored properly, consult package insert for expiration date.