CONTROLLED CLINICAL TRIAL WITH MINOCYCLINE IN TWO DOSAGE SCHEDULE IN RESPIRATORY INFECTIOUS DISEASES

In this paper the serum concentration of minocycline was compared when minocycline was administered to three healthy male adults on two different dosage schedules by the cross over method; 200 mg initially followed by two daily doses of 100 mg each, or followed by a single daily dose of 100 mg for 6 days. Accumulative raise of the drug was not found in either experiments and the greater difference between the results of the two experiments was observed in the minimum serum concentration than in the maximum one. Double blind controlled trials by two dosage schedules (100 mg or 200 mg daily) were carried out in the patients with pulmonary infections at seven institutes. It was apparently noted that the administration of minocycline showed superior therapeutic effects when it was given at the two daily doses of 100 mg each, than at the single daily dose of 100 mg. As for the appearance of side effects such as gastrointestinal disturbance and floating sensation there was no difference between the two groups. Introduction It is noted that minocycline (MINO, 7-dimethyl amino-6-deoxy-demethyl-tetracycline) is one of the long acting tetracycline (TC) derivatives and is distinguished from other TC derivatives by its potent bacteriocidal activity against TC resistant staphylococci. The blood concentration at 24 hours after the oral administration is still one thirds of that at 3 hours after the administration and is over the minimum inhibitory concentration against gram positive cocci. Therefore it was considered that this drug may have accumulative action by conse-