Experience with Isoniazid Prophylaxis in a Large City Health Department

¹ Surgeon, U. S. P. H. S., Communicable Disease Center, Tuberculosis Branch
² Director of Tuberculosis Clinics, City of Boston, Department of Health and Hospitals

Isoniazid prophylaxis therapy has been used in over 1,000 patients at the Tuberculosis Clinics of the Boston Health Department during the past seven years. Four hundred forty-two patients who have completed their course of therapy and have been followed up for an average of over three years are reviewed. The majority of patients received two years of daily isoniazid therapy at a dosage of 10 mg/kg. To this date, no case of clinically active tuberculosis has appeared among the 1,000 patients under observation. This experience strongly suggests both a short term prophylactic effect and a longer term lasting effectiveness of isoniazid prophylaxis.