Valganciclovir

Mechanism :

Valganciclovir is an L-valyl ester (prodrug) of ganciclovir that exists as a mixture of two diastereomers. After oral administration, both diastereomers are rapidly converted to ganciclovir by intestinal and hepatic esterases. Ganciclovir is a synthetic analogue of deoxyguanosine, which inhibits replication of human cytomegalovirus in vitro and in vivo.

Indication :

• Cytomegalovirus (CMV) retinitis in patients with AIDS
• Prevention of cytomegalovirus (CMV) disease in kidney, heart, and kidney-pancreas transplant patients at high risk
• Congenital CMV

Contraindications :

Contraindicated in patients with hypersensitivity to valganciclovir or ganciclovir.

Dosing :

Adverse Effect :

Leukopenia, thrombocytopenia, anemia, rash, abnormal LFTs, chills, edema, confusion ataxia, nervousness, paresthesia, psychosis, tremor, hypotension, hypertension, cardiac arrhythmias, gastrointestinal effects including abdominal pain, diarrhea, nausea, haemorrhage, eosinophilia, decreased blood glucose, fever, headache, insomnia, retinal detachment, alopecia, pruritus, urticaria, haematuria, increases in serum creatinine and urea also reported.

Interaction :

Zidovudine: Since both zidovudine and ganciclovir have the potential to cause neutropenia and anemia, some patients may not tolerate concomitant therapy with these drugs at full dosage.
Probenecid: Renal clearance of ganciclovir decreased which is consistent with an interaction involving competition for renal tubular secretion.
Imipenem-Cilastatin: Generalized seizures have been reported in patients who received ganciclovir and imipenem-cilastatin. These drugs should not be used concomitantly unless the potential benefits outweigh the risks.
Dapsone, Pentamidine, Flucytosine, Vincristine, Vinblastine, Adriamycin, Amphotericin B, Trimethoprim/Sulfamethoxazole combinations or other Nucleoside Analogues: Drugs that inhibit replication of rapidly dividing cell populations such as bone marrow, spermatogonia and germinal layers of skin and gastrointestinal mucosa may have additive toxicity when administered concomitantly with ganciclovir. Therefore, such drugs, should be considered for concomitant use with ganciclovir only if the potential benefits are judged to outweigh the risks involved.

Renal Dose :

Hepatic Dose :