Thomas S. Moulding

Cross-resistance in M. tuberculosis to kanamycin, capreomycin and viomycin

Drug resistant mutants to streptomycin, kanamycin, viomycin, capreomycin, and rifampicin were isolated from four strains of Mycobacterium tuberculosis. The mutants isolated from each parent were then tested for evidence of development of cross-resistance to other drugs. There was no cross-resistance between either streptomycin or rifampicin and any of the other drugs. Complete cross-resistance between viomycin and capreomycin was found. Cross-resistance between kanamycin and capreomycin, and kanamycin and viomycin was variable. A review of the medical histories of 27 patients with kanamycin-resistant tubercle bacilli indicated that cross-resistance with capreomycin and viomycin occurs, but is unpredictable. Because of this variability in cross-resistance and the fact that kanamycin is a more toxic drug than capreomycin, it is suggested that capreomycin be used in the first retreatment regimen for tuberculosis when streptomycin resistance has been demonstrated.

Rifampin in the Treatment of Drug-Resistant Mycobacterium tuberculosis Infections

Abstract Thirty patients with far advanced, multiple-drug-resistant pulmonary tuberculosis were treated with rifampin for four to 12 months. The regimens included rifampin in a daily dosage of 600 mg combined, whenever possible, with one or more other antituberculosis drugs to which in vitro susceptibility had been demonstrated. Quiescent status was achieved in 21 (70 per cent) of the patients, whereas in nine (30 per cent) cultures remained positive, or the patient relapsed after having initially achieved sputum negativity. The shortest duration of rifampin therapy producing culture conversion was 10 days, and the longest 90 days, with a mean of 40. In seven of the nine failures rifampin resistance developed, and all but one of these patients received rifampin without a satisfactory companion drug because of previously acquired resistance. However, 65 per cent of the patients receiving rifampin as the sole therapy attained quiescent status; to date only two have relapsed. No toxicity attributable to rifa...

The unrealized potential of the medication monitor.

The medication monitor is a dispenser with a time recording system for determining when patients remove medication. ft has demonstrated that nurses and physicians can estimate patient compliance with considerable accuracy. It could be used: (1) to assure that only patients actually ingesting medication are used to evaluate new drugs, (2) to study the factors that influence compliance and strategies to improve compliance, (3) to prevent escalation to more toxic drugs or expensive diagnostic procedures when failure to respond is due to poor compliance, (4) to supervise compliance when society has an overriding interest in therapeutic success, and (5) to monitor the effects of air pollution. Specially designed medication monitors could be used to provide the proper amount of compensatory medication when a patient forgets and to reduce the chance that a suicidal patient will impulsively take an overdose.

The medication monitor for studying the self-administration of oral contraceptives

The author notes that failure of the commonly used oral contraceptives is often related to failure of the woman to take the medication as prescribed. A medication monitor has been devised. Each tablet is packaged in a plastic holder and marked with the day of the week it is to be taken. The holders are stacked in sequence and markings are visible. A small uranium source and a paper-wrapped strip of photographic film are included. As each tablet is removed a spring moves the radioactive source down creating a record of dots on the film. Irregular removal of tablets is thus recorded. This method is considered a practical means of studying oral contraceptive use. The association of pregnancy or breakthrough bleeding with different degrees of omission can be determined and at what point in the treatment the lapse most frequently leads to these events. Also the effectiveness of attempts to improve the regularity with which women take medication could be determined and other contraceptive programs recommended for individual patients with poor film records.

Preventing Isoniazid Hepatotoxicity

Excerpt To the editor: The NIH Conference on isoniazid liver injury in the February issue (Ann Intern Med 84:181-192, 1976) presented an interesting observation that might be used to prevent isonia...