Abstract
Pharmacological drug interaction of nonsteroidal anti-inflammatory drugs was tested from the standpoint of their inhibitory effect on capillary permeability and analgesic action in mice by oral administration, and the following results were obtained. 1) The inhibitory effect of the combined use of naproxen with indomethacin on capillary permeability was weak, partial, and antagonistic. On the other hand, the combined effect of indomethacin with phenylbutazone and of naproxen with aminopyrine was additive. 2) The combined use of (a) aminopyrine with naproxen, (b) aminopyrine with phenylbutazone, and (c) aminopyrine with indomethacin action showed a slightly potentiating action on analgesis, and the degree of potentiation of the combination is decreased, in the order of a, b, and c. On the other hand, the combined effect of phenylbutazone with indomethacin and phenylbutazone with naproxen was additive, but the acute toxicity was potentiated in the latter combination. These results suggest that the potentiation of analgesic action may result from the combined use of a weak basic drug, aminopyrine, with weak acidic nonsteroidal antiinflammatory drugs.
