Hypercoagulability produced by treatment with acetohydroxamic acid

Abstract

Thrombosis has been observed with unusual frequency in patients receiving acetohydroxamic acid (AHA) for treatment of struvite nephrolithiasis. Because this clinical observation suggests a low-grade state of diffuse intravascular coagulation, standard clinical coagulation assays, platelet counts, and plasma fibrinopeptide A (FPA) levels were measured in patients before and during treatment with AHA. Coagulation assays, fibrinogen, and fibrin-split products were not significantly different when pretreatment and treatment values were compared. FPA levels were significantly elevated and platelet counts were significantly reduced in the treatment period, indicating augmented thrombin activity and consumption of platelets into thrombi or platelet microaggregates. FPA levels were elevated within 24 hours of the initiation of AHA therapy whereas platelet counts did not change significantly within the first 4 days of treatment. The data are consistent with low-grade intravascular coagulation with AHA treatment and suggest that patients treated with this agent should be observed cautiously for signs of thrombosis.