Names and pronunciation
(si-doh-foh′veer)
PDF page 276
Loading InternPractice…
Drug reference
(si-doh-foh′veer)
PDF page 276
Func. class.: Antiviral
PDF page 276
Chem. class.: Nucleotide analog
PDF page 276
ACTION: Suppresses cytomegalovirus (CMV) replication by selective inhibition of viral DNA synthesis
PDF page 276
USES: CMV retinitis in patients with HIV; used with probenecid
PDF page 276
CONTRAINDICATIONS: Hyper- sensitivity to this product, probenecid, sulfa products; direct intraocular injec- tion; proteinuria, renal disease/failure Precautions: Pregnancy, breastfeeding, children <6 mo, geriatric patients, pre- existing cytopenias, renal function impairment, platelet count <25,000/mm3, dehydration
PDF page 276
Black Box Warning: Neutropenia, infertility, secondary malignancy, pregnancy, nephro- toxicity, use only for CMV retinitis (AIDS) Black Box Warning: Use cytotoxic han- dling procedures • Allow to warm to room temperature • If product comes in contact with skin, wash with soap and water immediately • If zidovudine is used, reduce dose to 50% on cidofovir treatment days Intermittent IV INFUSION route • Dilute in 100 mL 0.9% saline solution before administration; give probenecid PO 2 g 3 hr prior to the cidofovir infusion and 1 g at 2 and 8 hr after ending the cidofovir infusion; give 1 L of 0.9% saline solution IV with each INFUSION of cidofovir, give saline INFUSION over 1-2 hr period immediately prior to cidofovir; patient should be given a second L if the patient can tolerate the fluid load (second L given at time of cidofovir or immediately afterward, should be given over 1-3 hr) • Give slowly; do not give by bolus IV, SUBCUT injection • Use diluted solution within 24 hr, do not freeze; do not use solution with par- ticulate matter or discoloration • Do not admix Black Box Warning: Nephrotoxicity: amphotericin B, foscarnet, aminoglyco- sides, pentamidine IV, NSAIDs, salicylates; wait 7 days after use to begin cidofovir Drug/Lab Increase: ALT, AST, alkaline phosphatase, glucose, cholesterol, BUN, creatinine, urine protein Decrease: neutrophils, platelets, calcium, potassium Black Box Warning: Renal, hepatic, in- creased hemopoietic studies, BUN; se- rum creatinine, AST, ALT, creatinine, CCr, A-G ratio, baseline and drip treatment, blood counts q2wk; watch for decreasing granulocytes, HB; if low, discontinue and restart after recovery; blood transfusions may be required, renal failure can occur, Fanconi syndrome • For GI symptoms: severe nausea, vomiting, diarrhea; severe symptoms may necessitate discontinuing product • Electrolytes and minerals: cal- cium, phosphorus, magnesium, sodium, potassium; watch closely for tetany dur- ing first administration C Black Box Warning: Blood dyscrasias (anemia, granulocytopenia); bruising, fa- tigue, bleeding, poor healing; leukopenia, neutropenia, thrombocytopenia: WBCs, platelets q2days during 2×/day dosing and every week thereafter; check for leu- kopenias with daily WBC count in prior leu- kopenia, with other nucleoside analogs, or for leukopenia counts <1000 cells/mm3 at start of treatment • Allergic reactions: flushing, rash, urticaria, pruritus • Monitor serum creatinine or CCr at least q2wk; give only to those with creati- nine levels ≤1.5 mg/dL, CCr >55 mL/ min, urine protein <100 mg/dL Black Box Warning: Pregnancy/breast- feeding: may cause fetal harm; use only if benefits outweigh fetal risk; do not use in breastfeeding; use contraception dur- ing and for 1 mo after last dose; males should use barrier method during and for 90 days after last dose
PDF pages 276, 277
SIDE EFFECTS CNS: Fever, chills, coma, confusion, abnormal thoughts, dizziness, bizarre dreams, headache, psychosis, tremors, somnolence, paresthesia, amnesia, anx- iety, insomnia, seizures CV: Dysrhythmias, hypo/hypertension EENT: Retinal detachment with CMV retinitis GI: Abnormal LFTs, nausea, vomiting, anorexia, diarrhea, abdominal pain, hemorrhage GU: Hematuria, increased creatinine, BUN, nephrotoxicity HEMA: Granulocytopenia, thrombocyto- penia, irreversible neutropenia, anemia, eosinophilia INTEG: Rash, alopecia, pruritus, acne, urticaria, pain at injection site, phlebitis RESP: Dyspnea
PDF pages 276, 277
INTERACTIONS
PDF page 277
TREATMENT OF OVERDOSE: Discontinue product; use hemodialysis; increase hydration HIGH ALERT
PDF page 278
DOSAGE AND ROUTES • Adult: IV INFUSION Induction: 5 mg/kg over 1 hr weekly × 2 wk; maintenance: 5 mg/kg over 1 hr every other wk, give with probenecid Renal dose • Adult: IV CCr ≤55 mL/min, do not use; CCr increase of 0.3-0.4 mg/dL above baseline, decrease dose to 3 mg/kg; CCr increase of ≥0.5 mg/dL above baseline or ≥2+ proteinuria, discontinue
PDF page 276
Available forms: Injection 75 mg/mL
PDF page 276
Administer:
PDF page 276
Assess: • Culture prior to initiating treatment; cul- tures of blood, urine, and throat may all be taken; CMV not confirmed by this method; diagnosis made by ophthalmic exam
PDF page 277
Evaluate: • Therapeutic response: decreased symp- toms of CMV
PDF page 277
CLINICAL CONSIDERATIONS
PDF page 277
Patient and caregiver information: • To notify prescriber if sore throat, swollen lymph nodes, malaise, fever oc- cur; may indicate other infections • To report perioral tingling, numbness in extremities, paresthesias; report rash immediately, mental/vision changes, uri- nary problems, abnormal bleeding • That serious product interactions may occur if OTC products are ingested; check with prescriber • That product is not a cure but will control symptoms • That regular ophthalmic exams, renal studies must be continued • That major toxicities may necessitate discontinuing product • To use contraception during treatment, that infertility may occur, and that men should use barrier contraception for 90 days after treatment
PDF pages 277, 278
PHARMACOKINETICS Terminal half-life 2.6 hr
PDF page 277
• Adult: IV INFUSION Induction: 5 mg/kg over 1 hr weekly × 2 wk; maintenance: 5 mg/kg over 1 hr every other wk, give with probenecid Renal dose
PDF page 276
• Adult: IV CCr ≤55 mL/min, do not use; CCr increase of 0.3-0.4 mg/dL above baseline, decrease dose to 3 mg/kg; CCr increase of ≥0.5 mg/dL above baseline or ≥2+ proteinuria, discontinue
PDF page 276