Hemolytic-uremic syndrome valacyclovir

Thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS) has occurred in patients with advanced HIV disease and also in allogeneic bone marrow transplant and renal transplant recipients taking valacyclovir at doses of 8 g/day. 

Valacyclovir is generally well tolerated, although nausea, vomiting, or rash occasionally occur. At high doses, confusion, hallucinations, and seizures have been reported. AIDS patients who received high-dosage valacyclovir chronically (ie, 8 g/d) had an increased incidence of gastrointestinal intolerance as well as thrombotic thrombocytopenic purpura and hemolytic-uremic syndrome this dose was associated with confusion and hallucinations in transplant patients. 

Like acyclovir, valacyclovir is a well-tolerated drug. The most common adverse effects of valacyclovir are headache and nausea. Other adverse events associated with valacyclovir administration include vomiting, weakness, dizziness, and abdominal pain. Thrombotic thrombocytopenic purpura/ hemolytic uremic syndrome has also been reported in a few patients after high doses of valacyclovir, as has confusion, hallucinations, and nephrotoxicity (Curran and Noble, 2001 Perry and Faulds, 1996). 

Valacyclovir 500-1000 mg qShrs 50% 100% 50% 25% Thrombotic thrombocytopenic purpur hemolytic uremic syndrome Avoid in transplant recipients... 

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