Action

Exerts antiviral effect by interfering with DNA synthesis of CMV, thereby inhibiting viral replication

Availability

Solution for injection: 75 mg/ml in 5-ml, single-use vials

Indications and dosages

➣ CMV retinitis in AIDS patients

Adults: 5 mg/kg I.V. infused over 1 hour q week for 2 continuous weeks; then 5 mg/kg I.V. once q 2 weeks as a maintenance dose

Dosage adjustment

• Renal impairment

Contraindications

• Hypersensitivity to drug, probenecid, or other sulfa-containing agents

• Creatinine level above 1.5 mg/dl, calculated creatinine clearance of 55 ml/minute or less, or urine protein level of 100 mg/dl or higher

• Concurrent use of nephrotoxic drugs

Precautions

Use cautiously in:

• renal impairment

• elderly patients

• pregnant or breastfeeding patients

• children younger than age 12 (safety and efficacy not established).

Administration

See Be aware that drug carries a high risk of nephrotoxicity. Follow administration instructions carefully, including preinfusion and postinfusion hydration with I.V. normal saline solution.

• Premedicate with probenecid 2 g P.O., as prescribed, 3 hours before starting cidofovir infusion.

• Before starting infusion, give 1 L of normal saline solution over 1 to 2 hours.

• Mix I.V. dose in 100 ml of normal saline solution and infuse over 1 hour using infusion pump.

• Give 1 L of normal saline solution during or immediately after cidofovir infusion (unless contraindicated).

• Administer probenecid 1 g 2 hours and 8 hours after infusion ends, as prescribed.

See If drug touches skin, flush thoroughly with water.

Adverse reactions

CNS: headache, seizures, coma

EENT: decreased intraocular pressure

GI: nausea, vomiting, diarrhea, anorexia, oral candidiasis

GU: proteinuria, nephrotoxicity

Hematologic: neutropenia

Hepatic: hepatomegaly

Metabolic: metabolic acidosis

Musculoskeletal: muscle contractions

Respiratory: dyspnea, increased cough

Skin: rash, alopecia

Other: pain, fever, chills, infection, pain at I.V. site

Interactions

Drug-drug. Nephrotoxic drugs: increased risk of nephrotoxicity

Drug-diagnostic tests. Alanine aminotransferase, alkaline phosphatase, aspartate aminotransferase, blood urea nitrogen, creatinine, lactate dehydrogenase: increased values

Bicarbonate, creatinine clearance, hemoglobin, neutrophils, platelets: decreased values

Patient monitoring

• Assess white blood cell count and creatinine and urine protein levels within 48 hours of each dose.

• Closely monitor intraocular pressure and visual acuity.

• Monitor hepatic enzyme levels in patients with hepatic disease.

Patient teaching

See Tell patient to immediately report fever, vision changes, nausea, vomiting, rash, or urinary output changes.

• Instruct patient to take probenecid, as prescribed, before each dose and to have regular eye examinations.

• Urge female patient of childbearing age to use effective contraception during and for 1 month after therapy.

• Instruct male patients to use barrier contraception during and for 3 months after therapy.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs and tests mentioned above.