[Tolerability of Asacard--controlled-release aspirin and aspirin-induced asthma]

Asacard is a microcapsulated, controlled-release form of acetylsalicylic acid, which delivers very low but constant amount of the drug directly into the intestine. The dose 162.5 mg Asacard, used in prevention of cardiovascular diseases, is thus sufficient to block platelets in the portal vein from synthesizing thromboxane but not high enough to enter the systemic circulation and block the formulation of prostacyclin and other prostaglandins. It is generally accepted that in aspirin-induced asthma (AIA) the bronchospasm is provoked by inhibition of prostaglandin synthesis with overproduction of cysteinyl leukotrienes. The aim of our study was to verify the hypothesis if Asacard, as a form of aspirin, which theoretically does not block prostacycline synthesis in systematic circulation, would be well tolerated by patients with AIA. We thus studied in an open study the tolerability of three single, increasing doses of Asacard in 10 patients with confirmed by oral challenge test aspirin intolerance (4 males, 6 females, mean age 40 years). Initially, the patients received 40 mg of Asacard and FEV1 and clinical symptoms were assessed every 30 minutes for 8 hours. A positive reaction was defined as a > or = 20% decline in FEV1 from baseline. Patients with negative reaction received 75 mg Asacard 7 days later. In absence of the reaction, the last dose 162.5 mg was administered a week later. In 5 out of 10 patients studied, Asacard given at single doses up to 162.5 mg was tolerated well. In the remaining 5, it provoked bronchospasm, a fall in FEV1 > or = 20% and other extrabronchial symptoms of aspirin intolerance. No correlation was found between the doses of regular aspirin, which provoked a fall in FEV1 > or = 20% during baseline oral provocation test and Asacard doses. In conclusion, any form of aspirin, even controlled-release, should not be prescribed for patients with AIA, because it may provoke symptoms of intolerance to this drug.