A Phase Istudy on cisapride (R 51 619), a new gastrointestinal prokinetic agent, was conducted in 12 healthy Japanese male volunteers. The safety and pharmacokinetics of the drug were studied in single oral doses of 2. 5, 5, 10, 20 and 40 mg.
The six men of group 1 received 2.5, 10 and 40 mg doses at intervals of five to sixweeks. The remaining six individuals (group 2) were given doses of 5 and 20 mg. Thedoses were increased step by step after the safety of the compound was confirmed.
No pronounced change was noted in vital signs, ECGs or laboratory tests. As tosubjective symptoms, borborygmi, which appear to be a pharmacological effect, were observed at the 20 and 40 mg dose levels. Reports of flushing, headache and feeling of heavy-headedness occurred after intake in the 40 mg group.However, these subjective symptoms were mild and transient.
Peak plasma levels were found about 1.3 hours after the administration and the biological half life of the β phase was about 8.5 hours.