Bioavailability of rectal aspirin in neurosurgical patients.

Serum salicylate levels were determined fluorimetrically in 12 neurosurgical patients after rectal and oral administration of 1.0 g aspirin. There was no significant difference in the AUC-value between the two routes of administration, but a slower rate of absorption with no clear peak effect was found after rectal administration. Rectal aspirin is useful in clinical situations in which mediation is difficult by the oral route, e.g. after neurosurgical and open-heart surgical interventions.