Erythromycin for chlamydiasis in pregnant women. Assessing adherence to a standard multiday, multidose course

To assess patient adherence among pregnant women infected with Chlamydia trachomatis given a self-administered, 10-day course of erythromycin prescribed as 500-mg tablets to be taken four times a day for the full 10-day period of treatment.

Study participants (n = 30) were given the standard, 10-day supply of 500-mg tablets of erythromycin and instructed to take one tablet four times daily for 10 days. Patients were blinded to the fact that the Medication Event Monitoring System was being used and that their adherence to this course of drug therapy was being monitored.

A 100% cure rate was achieved. The average percentage of therapeutic coverage actually achieved by the study participants declined with the length of erythromycin therapy. Further, as the duration of treatment increased, the longest interval between two successive doses of erythromycin also increased.

This study demonstrated the importance of assessing both the quantitative and temporal aspects of self-administered oral medication when assessing patient adherence. Moreover, since the length of the course of antibiotic therapy was shown to affect patient adherence, coupled with the 100% cure rate we observed, future research geared toward maximizing adherence while minimizing duration of treatment seems warranted.