Clindamycin (CLDM), a new antibiotic, was tried orally in the treatment of scarlet fever and hemolyticstreptococcal tonsillitis and evaluated with the following laboratory and clinical data:
1) Sensitivity of 51 hemolytic streptococcal strains against CLDM was investigated. The value: of MIC was found distributed between 0.006 and 0.195 mcg/ml.
2) Relationship between oral dose and bacteriological effects in vivo was studied employing thefindings of pharyngeal hemolytic streptococcus as a marker. One-time dose of 2 mg/kg was almost ineffec. tive in eradicating the cocci from the pharynx, but 5 mg/kg or more yielded the effects in 6-10 hours.
3) Twenty cases of scarlet fever in acute stage were given about 5-9 mg/kg LCDM every 8 hours for 5 days. In all the cases, there found marked clinical effects such as remmission of fever, recovery of ph aryngeal symptoms and disappearance of the cocci from the pharynx. After the halt of the medication, however, reappearance of the cocci in the pharynx was observed in 30% of them and fever recurrence in 20%.
4) Six cases of hemolytic-streptococcal tonsillitis were treated in the same manner as in the case of scarlet fever. The results were excellent in all the cases. Reappearance of the cocci was noted in two cases fever recurrence in no case.
5) As to side effects, vomiting was seen only once in one case who, however, tolerated the further me dication. Blood, urine and liver functions were tested in 19 cases at the end of the medication course, but no particular changes were revealed.
From these results, it is concluded that LCDM, used at the one-time dose of 5 mg/kg or more, is as effective to scarlet fever and hemolytic-streptococcal tonsillitis as the other antibiotics such as penicillin or erythromycin which are already authorized to these diseases.