Cidofovir

Verbatim source wording (UK SPC §4.2, Posology, Adults): 'Induction treatment. The recommended dose of cidofovir is 5 mg/kg body weight (given as an intravenous infusion at a constant rate over 1 hour) administered once weekly for two consecutive weeks. Maintenance treatment. Beginning two weeks after the completion of induction treatment, the recommended maintenance dose of cidofovir is 5 mg/kg body weight (given as an intravenous infusion at a constant rate over 1 hour) administered once every two weeks. Suspension of maintenance treatment with cidofovir should be considered in accordance with local recommendations for the management of HIV infected patients.' Method of administration, verbatim: 'The recommended dose, frequency, or infusion rate must not be exceeded. It must be diluted in 100 millilitres 0.9% (normal) saline prior to administration. The entire volume should be infused intravenously into the patient at a constant rate over a period of 1 hour by use of a standard infusion pump. To minimise potential nephrotoxicity, oral probenecid and intravenous saline prehydration must be administered with each Cidofovir 75 mg/ml Concentrate for Solution for Infusion.' PROBENECID, verbatim (§4.4): 'Two grams of probenecid should be administered 3 hours prior to the cidofovir dose and one gram administered at 2 and again at 8 hours after completion of the 1 hour cidofovir infusion (for a total of 4 grams). In order to reduce the potential for nausea and/or vomiting associated with administration of probenecid, patients should be encouraged to eat food prior to each dose of probenecid. The use of an anti-emetic may be necessary.' Probenecid is not optional: 'Concomitant use of probenecid is essential for reducing the pronounced nephrotoxicity of cidofovir to an extent that results in an acceptable benefit/risk balance of cidofovir therapy', and cidofovir is contraindicated in patients unable to receive it. SALINE PREHYDRATION: §4.2 and §4.4 require intravenous saline prehydration with every dose but the specific volume and timing fall inside the part of §4.4 truncated at the source-fetch limit — take the hydration protocol from the full SPC or local policy, not from this record. WHO SHOULD PRESCRIBE (§4.2): 'The therapy should be prescribed by a physician experienced in the management of HIV infection.' BEFORE EVERY DOSE (§4.2): 'Before each administration of cidofovir, serum creatinine and urine protein levels should be investigated.' INDICATION LIMIT (§4.4): 'The safety and efficacy of cidofovir has not been demonstrated in diseases other than CMV retinitis in adults with AIDS.' ELDERLY (§4.2): 'The safety and efficacy of cidofovir have not been established for the treatment of CMV disease in patients over 60 years of age. Since elderly individuals frequently have reduced glomerular function, particular attention should be paid to assessing renal function before and during administration of the medicinal product.' HANDLING (§4.2): preparation should be done in a laminar flow biological safety cabinet, with surgical gloves, safety glasses and a closed front surgical-type gown with knit cuffs; if cidofovir contacts the skin, wash membranes and flush thoroughly with water. Some sections of the product information we used were incomplete — check the full SPC.