The surgeon should be particularly concerned about which coagulation function in patients receiving anti-inflammatory or analgesic medications?

Platelet dysfunction, measured by bleeding time, has been associated with a long list of drugs. Among nonsteroidal anti-inflammatory and analgesic medications, aspirin, indomethacin, phenylbutazone, acetaminophen, and phenacetin have been implicated, along with aminopyrine and codeine. Ibuprofen, however, has not. In addition, many antibiotics, anticonvulsants, and sedatives have been associated with thrombasthenia. Any time platelet abnormalities are suspected, a careful review of the drugs the patient is receiving should be undertaken, and a measurement should be made of the platelet count and bleeding time. Platelet dysfunction does not affect APTT, PT, reptilase, or thrombin times.