• Management of cytomegalovirus (CMV) retinitis in HIV-infected patients (with probenecid).

Contraindicated in:

• Hypersensitivity to cidofovir, probenecid, or sulfonamides
• Serum Cr >1.5 mg/dL, CCr 55 mL/min, or urine protein 100 mg/dL (2+ proteinuria)
• Concurrent use of foscarnet, amphotericin B, aminoglycoside anti-infectives, NSAIDs, or IV pentamidine.

Use Cautiously in:

• OB: Pedi: Safety not established
• Lactation: Breastfeeding is not recommended in HIV-positive patients

Exercise Extreme Caution in:

• Any condition or medication that ↑ the risk of dehydration.

CNS: headache, weakness.

EENT: ↓intraocular pressure, hearing loss, iritis, ocular hypotony, uveitis.

Resp: dyspnea, pneumonia.

GI: HEPATOTOXICITY, PANCREATITIS, abdominal pain, nausea, vomiting, anorexia, diarrhea.

GU: RENAL FAILURE, proteinuria.

Derm: alopecia, rash.

F and E: ↓serum bicarbonate.

Hemat: neutropenia, anemia.

Metab: METABOLIC ACIDOSIS.
Misc: chills, fever, infection.

Drug-Drug:

• ↑risk of nephrotoxicity with aminoglycosides, amphotericin B, foscarnet, and pentamidine and should be avoided; wait 7 days after giving other nephrotoxic agents.
• Probenecid, which is required concurrently, may interact with acetaminophen, acyclovir, ACE inhibitors, barbiturates, benzodiazepines, bumetanide, methotrexate, famotidine, furosemide, NSAIDs, theophylline, and zidovudine.

(Generic available)

• Solution for injection: 75 mg/mL;

• IV (Adults): 5 mg/kg once weekly for 2 wk, followed by 5 mg/kg every 2 wk (must be given with probenecid).

Vistide

• Suppresses replication of CMV by inhibiting viral DNA synthesis.

• Slows progression of CMV retinitis; may not be curative.

Therapeutic Classification: antivirals

Absorption: IV administration results in complete bioavailability.

Distribution: Unknown.

Metabolism/Excretion: Excreted mostly unchanged by the kidneys.

Half-life: Unknown.

• Inform patient that cidofovir is not a cure for CMV retinitis and that retinitis may continue to progress during and after therapy.
• Inform patient that concurrent antiretroviral therapy may be continued. However, zidovudine therapy should be temporarily discontinued or decreased by 50% on the days of cidofovir therapy because of the effects of probenicid on zidovudine.
• Advise patient of the possibility of renal toxicity from cidofovir. Emphasize the importance of routine lab tests to monitor renal function.
• Discuss with patient the possibility of hair loss. Explore coping strategies.
• Advise patients to have routine ophthalmologic exams after cidofovir therapy.
• Inform patient that cidofovir may have teratogenic effects. Women should use contraception during and for 1 mo after therapy. Men should use barrier contraception during and for 3 mo after therapy.

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