Abstract
Tetracycline is expected to be as effective as erythromycin in the treatment of pneumonia due toMycoplasma pneumoniae. In this clinical trial 12 cases with pneumonia due to Mycoplasma pneumoniaewere given doxycycline (Vibramycin ‘Pfizer’), a long-acting derivative of tetracycline. Judging from time periods required for defervescence, improvement in symptoms such as cough and disappearance of shadows on chest X-ray, the therapeutic effect of doxycycline was excelletit in 8 cases and good in 4 cases.