PubMed Health⌕ Search

Biomedical subjects

C V Ramakrishnan

Publications and source records attributed to C V Ramakrishnan.

At least 55 records · Page 3Linked to original sources
PubMed1971

Two controlled studies of the efficacy of isoniazid alone in preventing relapse in patients with bacteriologically quiescent pulmonary tuberculosis at the end of one year of chemotherapy.

An earlier report showed that, in patients with bacteriologically quiescent pulmonary tuberculosis at the end of 1 year of chemotherapy, isoniazid alone in a single daily dose of 150-200 mg, given as maintenance therapy in the second year, did not markedly prevent relapse over a 4-year period of follow-up in patients who had had residual cavitation (the "open-negative" syndrome) at 1 year, but was highly effective in patients who had not. As a result of these findings, two controlled studies, reported here, were undertaken.The first study was undertaken in patients with bacteriologically quiescent disease and residual cavitation at 1 year, and investigated the value of isoniazid in a higher daily dose (400 mg) throughout the second year; this is known to be the optimum therapeutic dose when isoniazid is prescribed alone for 1 year in the initial treatment of the disease. The second study was carried out in patients with bacteriologically quiescent disease and no residual cavitation at 1 year, and sought to determine the value of a shorter duration (6 months) of chemotherapy in the second year with a daily dose of 300 mg of isoniazid. Neither of the two isoniazid regimens was highly satisfactory, although both appeared to have had some effect in preventing relapse during the 4-year period of follow-up.

Clinical Trials as Topic↗
PubMed1970

Attack rate of tuberculosis in a 5-year period among close family contacts of tuberculous patients under domiciliary treatment with isoniazid plus PAS or isoniazid alone.

This report from the Tuberculosis Chemotherapy Centre, Madras, considers the risk, over a 5-year period, to close family contacts of sputum-positive patients treated at home for 1 year with a standard regimen of isoniazid plus PAS or one of 3 regimens of isoniazid alone. The attack rate of tuberculosis in the contacts did not appear to be influenced by the treatment received by the patients in the first year or by the duration in the 5-year period for which the patients had (1) positive sputum smears, (2) positive cultures, or (3) isoniazid-resistant cultures. Further, over half the cases of tuberculosis developed in the first year, many of these being in the first 3 months. These findings confirm the conclusions reached from an earlier study, namely, that the major risk to the contacts is from exposure to the infectious patient before diagnosis, and that the risks from the other possible sources of infection (the patient during treatment and the urban environment of Madras) are, in comparison, small.

Ambulatory Care↗
PubMed1969

A 5-year study of patients with pulmonary tuberculosis treated at home in a controlled comparison of isoniazid plus PAS with 3 regimens of isoniazid alone.

This report from the Tuberculosis Chemotherapy Centre, Madras, describes the progress, over a 5-year period, of 341 patients with newly diagnosed, sputum-positive tuberculosis. All the patients were treated on a domiciliary basis. In the first year, the patients received, on the basis of random allocation, a standard regimen of isoniazid plus PAS or 1 of 3 regimens of isoniazid alone. Previous reports have shown that the response in the first year was substantially superior with the standard regimen, and that the bacteriological relapse rates in the second year were fairly similar for the 4 regimens. The findings in the present report extend the latter conclusion to the end of 5 years. Further, when considered together with the findings in an earlier study, they have shown that isoniazid, given as maintenance chemotherapy in the second year, was highly effective in preventing bacteriological relapse in patients who, at 1 year, had bacteriologically quiescent disease and no residual cavitation; the effect was, however, less marked in patients with residual cavitation at 1 year.Patients who were clear-cut failures of the allocated chemotherapy and those who had a bacteriological relapse in the second or subsequent years were usually re-treated with streptomycin plus PAS or streptomycin plus pyrazinamide, and if this was ineffective, with cycloserine plus thioacetazone or cycloserine plus ethionamide.Considering the findings over the 5-year period for all patients, 16 died from non-tuberculous causes and 1 took his discharge prematurely. Of the remainder, 86% had bacteriologically quiescent disease at 5 years, 6% had bacteriologically active disease and 8% had died of tuberculosis. These findings confirm the value of well-organized domiciliary chemotherapy, which was established by an earlier report from the Centre, and are particularly encouraging for developing countries such as India, where tuberculosis is a major problem and resources are limited.

Aminosalicylic Acids↗
PubMed1968

Toxicity of pyrazinamide, administered once weekly in high dosage, in tuberculous patients.

The success of a twice-weekly regimen of streptomycin plus isoniazid, reported earlier from the Tuberculosis Chemotherapy Centre, Madras, prompted an investigation at the Centre of various once-weekly regimens of chemotherapy. In this context, a pilot study was undertaken in 19 patients to assess the toxicity of high-dosage pyrazinamide (70 mg/kg of body-weight), when administered once weekly, together with isoniazid (14 mg/kg of body-weight) and streptomycin (1 g), for at least 6 months. Serial estimations of SGOT and SGPT activity, urine tests for urobilin and bilirubin and haematological investigations were undertaken at frequent intervals. None of the patients showed any clinical evidence of hepatotoxicity; however, there was a slight and transient elevation in aminotransferase activity, probably of a non-specific nature, at 2 weeks. These findings are encouraging for the use of high-dosage pyrazinamide in once-weekly regimens of chemotherapy.

Adult↗