Effect of complex formation on drug absorption. 8. Intestinal transfer characteristics of the salicylamide-caffeine system

Tolfenamic acid, metoclopramide, caffeine and their combinations in the treatment of migraine attacks

Tolfenamic acid is a fenamate which inhibits prostaglandin (PG) biosynthesis and may act as a PG antagonist as well. Caffeine and metoclopramide are used in combination with analgesics and ergotamine in the treatment of migraine attacks, but controlled clinical studies on fixed combinations with analgesics are rare. The effects of orally given tolfenamic acid (200 mg), caffeine (100 mg), metoclopramide (10 mg), tolfenamic acid + caffeine (200 mg + 100 mg), tolfenamic acid + metoclopramide (200 mg + 10 mg) and placebo were studied in 49 migraine patients (3 men, 46 women) in a double-blind randomized cross-over study comprising 482 migraine attacks. The patients were allowed to take either one or two capsules of each preparation for an attack. Additional drugs were allowed after 3 h. Parameters characterizing the effects and side-effects of the drugs were registered. Tolfenamic acid and its combinations were found to be effective in the treatment of acute migraine, but caffeine and metoclopramide alone did not differ from placebo. Combination with metoclopramide was better than tolfenamic acid alone as judged by the smaller dose needed and the intensity of attack. Between tolfenamic acid alone and its caffeine combination there were no statistically significant differences.

Everted rat intestinal sacs as an in vitro model for assessing absorptivity of new drugs

An in vitro model that utilizes everted rat intestinal sacs was evaluated for assessing the absorptivity of several analogs of potential drug substances prior to formulation work and clinical trials. This model not only is a useful qualitative tool for assessing absorptivity of structurally related compounds but also yields some insight into the process involved in drug absorption. Notwithstanding the complexities involved in the absorption processes, the data support the hypothesis that the absorption of organic electrolytes mainly takes place by the partitioning of the unionized species into the lipoidal membranes and then diffusion.