Temporal trends of pharmacologic treatments for tuberculosis and multidrug resistant tuberculosis following dissemination of treatment guidelines in South Korea

BACKGROUND/PURPOSE(S)

The World Health Organization (WHO) released treatment guidelines for multidrug resistant tuberculosis (MDR-TB) in 2008, with subsequent revisions in 2011; Korea disseminated corresponding guidelines in 2011 and 2014, respectively. Thus, we aimed to investigate the temporal trends of and the updated guideline's impact on the prescription patterns of anti-TB drugs.

METHODS

We conducted a time-series study using Korea's nationwide healthcare database (2007-2015), where patients with TB or MDR-TB were included. Only anti-TB drugs prescribed during the intensive phase of treatment for TB (two months) or MDR-TB (eight months) were assessed. We estimated the annual utilization of TB treatment regimens and the relative difference (RD) in the proportion of MDR-TB treatment medications between the following periods: before the first Korean guideline (June 2008 to March 2011); between the first and revised guidelines (April 2011 to July 2014); after the revised guideline (August 2014 to December 2015).

RESULTS

Of 3523 TB (mean age 54.1 years; male 56.8%) patients, treatment regimens for TB complied with guideline recommendations as >80% of patients received either quadruple (mean 66.8%) or triple (14.5%) therapy of first-line anti-TB drugs. Following the WHO's guideline update, prescription patterns changed accordingly among 111 MDR-TB (mean age 46.0 years; male 67.6%) patients, as use of pyrazinamide (RD +20.3%) and prothionamide (+11.5%) increased (recommended to be compulsory), and streptomycin (-43.1%) decreased (ototoxicity risks).

CONCLUSIONS

Anti-TB drug prescription patterns for both TB and MDR-TB well reflected WHO's treatment guideline as well as corresponding domestic guidelines of South Korea.

A recombinant selective drug-resistant M. bovis BCG enhances the bactericidal activity of a second-line anti-tuberculosis regimen

Drug-resistant tuberculosis (DR-TB) poses a new threat to global health; to improve the treatment outcome, therapeutic vaccines are considered the best chemotherapy adjuvants. Unfortunately, there is no therapeutic vaccine approved against DR-TB. Our study assessed the therapeutic efficacy of a recombinant drug-resistant BCG (RdrBCG) vaccine in DR-TB. We constructed the RdrBCG overexpressing Ag85B and Rv2628 by selecting drug-resistant BCG strains and transformed them with plasmid pEBCG or pIBCG to create RdrBCG-E and RdrBCG-I respectively. Following successful stability testing, we tested the vaccine's safety in severe combined immune deficient (SCID) mice that lack both T and B lymphocytes plus immunoglobulins. Finally, we evaluated the RdrBCG's therapeutic efficacy in BALB/c mice infected with rifampin-resistant M. tuberculosis and treated with a second-line anti-TB regimen. We obtained M. bovis strains which were resistant to several second-line drugs and M. tuberculosis resistant to rifampin. Notably, the exogenously inserted genes were lost in RdrBCG-E but remained stable in the RdrBCG-I both in vitro and in vivo. When administered adjunct to a second-line anti-TB regimen in a murine model of DR-TB, the RdrBCG-I lowered lung M. tuberculosis burden by 1 log10. Furthermore, vaccination with RdrBCG-I adjunct to chemotherapy minimized lung tissue pathology in mice. Most importantly, the RdrBCG-I showed almost the same virulence as its parent BCG Tice strain in SCID mice. Our findings suggested that the RdrBCG-I was stable, safe and effective as a therapeutic vaccine. Hence, the "recombinant" plus "drug-resistant" BCG strategy could be a useful concept for developing therapeutic vaccines against DR-TB.

Rifampin Induces Expression of P-glycoprotein on the THP1 Cell-Derived Macrophages, Causing Decrease Intramacrophage Concentration of Prothionamide

Rifampin (RIF) has been widely used for the treatment of bacterial infections, including tuberculosis (TB). Treatment of drug-resistant TB is a global problem because of reduced drug efficacy. The present study determined the effect of RIF on MDR1 gene (P-glycoprotein, P-gp) expression in THP1 macrophages and analyzed the intracellular concentration of the anti-TB drug prothionamide in the presence of RIF. RIF treatment significantly induced MDR1 protein and mRNA levels in phorbol 12-myristate 13-acetate-stimulated THP1 macrophages (p < 0.001 and 0.01, respectively). The pregnane X receptor inhibitors resveratrol and ketoconazole significantly suppressed RIF-induced P-gp expression in THP1 macrophages (p < 0.05). RIF-treated THP1 macrophages also exhibited strong efflux of P-gp substrate, resulting in a reduced intracellular concentration of rhodamine-123 and prothionamide (p < 0.01 and 0.05, respectively). By contrast, the P-gp inhibitor cyclosporine A significantly increased intracellular concentration of rhodamine-123 and prothionamide (p < 0.001 and 0.05, respectively). The present results suggest that the usage of RIF together with P-gp-substrate drugs to treat TB may lead to deteriorated treatment efficacy because of the lower intracellular drug concentration. Further studies would be necessary to know the influence of RIF-induced P-gp induction on the treatment outcome of patients with TB.

Case Report: Carbapenemase-Producing Enterobacteriaceae in an Asylum Seeker with Multidrug-Resistant Tuberculosis

A Syrian asylum seeker with multidrug-resistant tuberculosis (TB) developed a bronchopleural fistula after pneumonectomy. Although screening tests were negative on admission, carbapenemase-producing Enterobacteriaceae were cultured after a few months of TB treatment. Prevalence of multidrug-resistant organisms is reported to be increased in asylum seekers compared with the general Dutch population. Arduous conditions during transit and interrupted health care delivery in our patient led to multiple-resistant microorganisms that complicated treatment.

Low Serum Concentrations of Moxifloxacin, Prothionamide, and Cycloserine on Sputum Conversion in Multi-Drug Resistant TB

PURPOSE

Low serum concentrations of drugs used to treat multi-drug resistant tuberculosis (MDR-TB) have occasionally been associated with treatment failure. We determined the frequencies of low serum concentrations of anti-MDR-TB drugs, and assessed the effects of these concentrations on 2-month sputum conversion.

MATERIALS AND METHODS

The serum levels of moxifloxacin (MF), prothionamide (PTH), and cycloserine (CS) were determined for 89 serum samples by high-pressure liquid chromatography-tandem mass spectrometry.

RESULTS

Low serum concentrations of MF, PTH, and CS below the minimal levels of the normal ranges were 83.3% (20/24), 59.2% (29/49), and 71.2% (47/66), respectively. There were no significant differences between the 2-month sputum conversion group (n=25) and the 2-month sputum non-conversion group (n=4) in median drug concentrations (μg/mL) of MF (1.46 vs. 1.60), PTH (0.91 vs. 0.70), and CS (14.90 vs. 14.90). However, a poor compliance rate was significantly greater in the 2-month sputum non-conversion group (75.0%, 3/4) than in the 2-month sputum conversion group (0%, 0/25) (p=0.001).

CONCLUSION

The frequency of low serum concentrations of anti-MDR-TB drugs was substantial and might not affect the 2-month sputum conversion rate. Larger prospective studies with timely sampling are needed to investigate the role of therapeutic drug monitoring in MDR-TB.

[Clinical analysis of protionamide and para-aminosalicylic acid induced hepatotoxicity in 129 cases]

OBJECTIVE

To investigate drug-induced liver injury (DILI) in tuberculosis (TB) patients treated with protionamide (Pto) and (or) para-aminosalicylic acid (PAS), and therefore to provide data for using second-line anti-tuberculosis drugs and risk prediction of liver damage.

METHODS

A retrospective analysis was performed for TB patients treated with regimens containing Pto and (or) PAS in Beijing Chest Hospital during Jan. 2008 to Jan. 2013. Cases with DILI were identified, and associated factors including patients' age and gender, time of onset, severity, clinical manifestations and prognosis of DILI were analyzed. The 2 groups were compared with χ(2) test. P < 0.05 was considered to be significant.

RESULTS

A total of 1714 cases were admitted, among whom 226 experienced liver damage during treatment, of which 97 cases were excluded because of underlying alcoholic liver disease, viral hepatitis B and C. Finally, 129 cases were diagnosed as having DILI, resulting in an overall incidence of 7.5% (129/1714), being 9.2% (59/641) in females, and 6.5% (70/1073) in males (χ(2) = 4.143, P < 0.05). DILI in most patients occurred between 1 week to 2 months, with 30.2% (39/129) within 2-4 weeks. 47.3% (61/129) of the patients showed no obvious clinical symptoms of hepatotoxicity. Among different regimens, combination of Pto, PAS and PZA resulted in the highest rate of DILI (20.7%, 19/92), while the rate was 9.8% (8/82) for the combination of Pto and PZA, P < 0.05.

CONCLUSIONS

DILI caused by Pto and PAS should be taken into account, especially in female patients and for multi-drug combination therapy. Liver function should be monitored even in patients without related clinical manifestations for early identification and treatment, and therefore avoiding severe liver damage.

Treatment of tuberculosis in South Kazakhstan: clinical and economical aspects

BACKGROUND AND OBJECTIVE

Since 1990, the tuberculosis incidence rate in Eastern Europe and post-Soviet republics has been increasing in many countries including Kazakhstan. This problem is particularly important in Kazakhstan regions with limited financial resources, among them - in South Kazakhstan province. The aim of this study was to investigate the main clinical and antibiotic-related economic aspects of tuberculosis treatment in South Kazakhstan province.

MATERIAL AND METHODS

In total, 502 patients participated in the study. They were hospitalized to the tuberculosis dispensary of Sayram district (South Kazakhstan province) in 2007-2013. Statistical analysis included logistic regression for better treatment outcomes and analysis of antibiotic treatment costs.

RESULTS

Two-thirds of patients had infiltrative tuberculosis (67%). Positive treatment outcomes were determined in 85% of cases. The patients were mostly treated with cycloserine, protionamide, capreomycin, and ofloxacin. The majority of antibiotic costs were related to the treatment with capreomycin. In case of the positive results of the test for Mycobacterium tuberculosis, antibiotic expenses were almost 3 times greater than in case of negative test results (P<0.001).

CONCLUSIONS

The majority of patients had extensively drug-resistant tuberculosis. The negative results of the test for Mycobacterium tuberculosis at discharge were not related to pretreatment factors. Antibiotic-related costs were significantly higher in case of the positive results of the test of Mycobacterium tuberculosis, but were not associated with gender, residence place, hospitalization recurrence, or main blood test results before treatment.

[Optimization of chemotherapy regimens in children with primary pulmonary tuberculosis]

The efficiency of treatment was analyzed in 142 children aged 3-14 years who had local forms of primary pulmonary tuberculosis. Therapy was performed according to regimens 3 and 1, by using individual dosage regimens depending on the extent and severity of a specific process, the presence of complications, and age-related features. In minor tuberculosis, solitary calcifications being detected without signs of the activity of tuberculous infection, the basic course of therapy was 6-8 months; it was performed using 2 drugs in individual cases. In disseminated and complicated processes, eliminated intoxication and visible X-ray inflammatory changes were observed in 58.8-61.7% of children by months 3-4 of treatment, which required a longer intensive phase, by administering 3 drugs in the continuation phase till 6-9 months.

Can leprosy be eradicated with chemotherapy? An evaluation of the Malta Leprosy Eradication Project

The Malta Leprosy Eradication Project (MLEP) was proposed in 1971 by Freerksen with the aim of eradicating leprosy in Malta. The project involved re-treatment of all known cases in Malta as of 1972 and all new cases thereafter with a regimen consisting of Isoprodian (a combination of dapsone, prothionamide and isoniazid) and rifampicin for varying intervals depending on the severity of their disease and their response to treatment. Overall the response to therapy was excellent with an extremely low relapse rate. During the 30 years of the project the incidence of leprosy steadily decreased continuing a decline that had started at least two decades earlier and Freerksen declared the disease eradicated from Malta in 2001. Although given the long incubation period of leprosy cases may still be occasionally detected in the future, the disease has been basically eradicated at this time and there are no patients currently receiving treatment. This work was done at the leprosy clinic, Boffa Hospital, Floriana, Malta.

A clinical trial of ethionamide and prothionamide for treatment of lepromatous leprosy

In 1982-1984 we conducted a six-month clinical trial in 50 previously untreated lepromatous leprosy patients randomly assigned to directly observed monotherapy with one of two thioamides, ethionamide or prothionamide, each given six times a week at doses of either 250 mg or 500 mg. The findings of this study have only recently been analyzed, and the potential for the use of these thioamides in leprosy patients placed in perspective. However, because of the small number of patients included in this study, the results must be interpreted with some caution. Clinical improvement was noted in 74% of the patients treated with ethionamide and in 83% of those treated with prothionamide. Therapy was well tolerated and drug-related hepatotoxicity did not require discontinuation of therapy. The 500-mg dose of both ethionamide and prothionamide resulted in loss in Mycobacterium leprae viability more rapidly than did the 250-mg dose, and prothionamide at both dose levels was superior to the equivalent dose of ethionamide. Overall killing of M. leprae in this study was found to be similar to that obtained previously with dapsone and clofazimine, but less than was obtained with rifampin, minocycline, clarithromycin, pefloxacin, and ofloxacin.

Longitudinal study of tuberculosis outcomes among immunologically naive Aché natives of Paraguay

This study documents the course of a tuberculosis epidemic in an immunologically naive group of South American Indians within fewer than 20 years after first sustained contact with outsiders. Groups of Northern Aché (ah-CHAY) of eastern Paraguay were contacted and settled on reservations between 1971-1979. Not surprisingly, the Aché are very susceptible to tuberculosis, and the epidemiological characteristics of the disease are quite different from those of populations that have had tuberculosis for centuries. Within 6 years of the first detected case of tuberculosis among the Aché, the prevalence rate of active tuberculosis cases reached 18.2%, and of infected cases among adults, 64.6%, some of the highest rates ever reported for any human group. Remarkably, males and females are equally likely to have been diagnosed with active tuberculosis, Aché children between birth and 5 years of age are least vulnerable to tuberculosis, high nutritional and socioeconomic status do not decrease the risk of disease or infection, and children immunized with BCG are less responsive to tuberculin challenge than are other children. Moreover, similar to the Yanomamö, but unlike populations of European or African descent, a high percentage of Aché with active disease test negative on tuberculin challenge tests (purified protein derivative; PPD). These differences may be due to a high prevalence of diminished cell-mediated immunity, and T-helper 2 dominance. We also hypothesize that these immunological characteristics, low genetic diversity, hostile intergroup interactions, and behavioral noncompliance to treatment protocols together contribute to the high rates of active disease observed. Existing tuberculosis control programs are poorly equipped to handle the impact of these causal complexities on the course of recent tuberculosis epidemics that have quickly spread throughout native communities of Latin America during the last decade.

[Chemotherapy-induced erythema nodosum leprosum: successful treatment with thalidomide]

The severity and outcome of a chronic granulomatous infection caused by M. leprae depend on the cell-mediated immunity towards the pathogen. The disease classification is based on the host's response to M. leprae ranging from high to low resistance (polar tuberculoid leprosy to polar lepromatous leprosy). The host's position in the spectrum is not stable; leprosy reactions reflecting changed immune status may occur spontaneously or during chemotherapy. The type II reaction or erythema nodosum leprosum can most often be seen in patients with lepromatous leprosy, a multiorgan disease characterized by an unrestricted bacillary replication. Clinically, this reaction is characterized by crops of painful bright pink, dermal and subcutaneous nodules arising in clinically normal skin, in association with fever, malaise, glomerulonephritis and arthralgias. Therefore, prompt institution of immunosuppressive therapy with corticosteroids or thalidomide is recommended. This case report describes the development of erythema nodosum leprosum during chemotherapy treated successfully with thalidomide. Furthermore, immunologic effects and potential side effects of this drug are discussed.

The Malta Project--a country freed itself of leprosy. A 27-year progress study (1972-1999) of the first successful eradication of leprosy

The successful conclusion of the first leprosy eradication program carried out with combination therapy is reported. This program started in Malta in June 1972. It was based on extensive experimental and clinical studies and was formally concluded on 31 December 1999. No new infections occurred after the start of this 27-year progress report. The youngest patient was 16, and the eldest 83 years old. Of the total of 261 cases in the project, 201 had already received pretreatment [mainly with diaminodiphenylsulfone (DDS)] at the start. Sixty-one cases had no pretreatment. These were predominantly elderly patients who were late in deciding to have treatment. The very long follow-up period totaling 27 years was consistently maintained in order to be able to refute all potential objections empirically, e.g. with regard to relapses at a late stage. Besides the overall symptoms which are typical for the broad picture of leprosy, the involvement of the eyes was very striking (at least 50%). The therapeutic effect was of very rapid onset in these cases without surgery. Rifampicin (RMP) + isoniazid + prothionamide + DDS (trade name Isoprodian-RMP) was used as medication in a fixed combination. This fixed combination had already proved to be highly effective in the treatments during the course of the project, surprising therapy results (including lifesaving effects) were also noticed in other diseases.

A simple and rapid technique for the detection of rifampin resistance in Mycobacterium leprae

The rifampin resistance of Mycobacterium leprae is due to missense mutations in the rpoB gene encoding the beta-subunit of the essential enzyme RNA polymerase. A rapid and very simple method has been developed to detect rifampin resistance in small numbers of M. leprae present in biopsies. It involves polymerase chain reaction amplification of a defined region of the rpoB gene followed by single-strand conformational polymorphism analysis (PCR-SSCP). The reliability of the method has been tested on a sample of known drug-resistant and susceptible isolates of M. leprae.

Effects of chemotherapy on antibody levels directed against PGL-I and 85A and 85B protein antigens in lepromatous patients

IgG antibodies against antigens 85A and 85B from Mycobacterium bovis BCG, IgM antibodies against phenolic glycolipid-I (PGL-I) and circulating PGL-I antigen were measured in the serum of 11 patients with lepromatous leprosy receiving multidrug therapy (MDT). Before treatment, 6 patients were reactive to antigen 85A, 10 patients to antigen 85B, and 11 patients to PGL-I; circulating PGL-I was detected in the sera of all of them. After 2 years of MDT PGL-I antigen could no longer be detected in all of the patients, except for two who were not compliant with treatment. IgG antibodies directed against the 85A and 85B antigens and IgM antibodies against the PGL-I antigen also decreased significantly during treatment but more slowly. The determination of circulating PGL-I antigen remains the most appropriate tool for monitoring lepromatous leprosy under MDT.

A case of relapse with drug-susceptible M. leprae after multidrug therapy

A male born in 1930 was diagnosed as smear-positive borderline leprosy in 1971, and was treated with dapsone and/or sulfamethoxypyridazine from 1972 to 1980 with clinical improvement. However, new skin lesions with smears strongly positive appeared in August 1980, and he was diagnosed as having downgraded to lepromatous (LL) leprosy, but the bacilli recovered from the skin biopsy were fully susceptible to both dapsone and rifampin by mouse foot pad technique. Between 1981 and 1983, the patient was treated with 24 months of rifampin 600 mg and dapsone 100 mg daily, supplemented with prothionamide 500 mg daily during the initial 3 months, and his skin lesions gradually improved during treatment with the combined regimen. Afterward, the patient was kept under surveillance without treatment. From 1984 to 1986, his skin smears were negative, and no bacilli could be found from a skin biopsy taken in 1985. Then in 1987, 52 months after stopping treatment, new skin lesions appeared with a high concentration of Mycobacterium leprae (2 x 10(6)/mg tissue). The drug-susceptibility test again demonstrated that the organisms were fully susceptible to both dapsone and rifampin. Apparently the relapse was due to remultiplication of drug-susceptible persisters.

An outbreak of isoniazid resistant tuberculosis in Glasgow 1981-1988

An increase in the number of patients attending the Victoria Infirmary, Glasgow with isoniazid resistant tuberculosis, prompted a survey of the incidence of the condition in Glasgow. There was a clustering of cases among the homeless and/or alcoholic population of the city, particularly between the years 1982 and 1986. This suggests an outbreak of isoniazid resistance among that population, probably spread from a single, but unidentified source.

Random variation in tuberculin sensitivity in schoolchildren. Serial skin testing before and after preventive treatment for tuberculosis

Schoolchildren were Mantoux-tested with 2 TU freeze-dried PPD RT23, and the strong reactors with indurations of 14.0 mm or more were selected for treatment with one of three different fixed drug combinations containing isoniazid or with placebo for 2 to 6 months. The initial tuberculin test was repeated after 8, 14, and 27 months. Of the 8,934 black schoolchildren initially tested, 5,165 did not react to the skin test, 2,898 had indurations up to 14.0 mm, and 871 reacted strongly. Of these strong reactors, 808 were allocated to four preventive treatment groups. On completion of treatment, the mean tuberculin reaction for all groups was significantly decreased. Because the placebo group showed changes similar to those seen in the other treatment groups, the tuberculin skin test is probably not suitable for monitoring the success of preventive therapy. Differences between skin test results before and after treatment when retesting only strong reactors are caused by a combination of effects that are difficult to distinguish. Assuming random variation in tuberculin sensitivity, the decrease can be explained as a combined effect of regression to the mean and some boosting. The increased reaction sizes in the subsequent Mantoux tests are explained by the booster phenomenon and possibly by reinfection. When using a cutting point for deriving a positive reactor, the chance of being selected for preventive treatment may depend primarily on the moment in time when the test is done. Thus, all reactors with no recent BCG vaccination should equally be considered for treatment.

New forms of multidrug therapy for the treatment of leprosy. First report for the practice on rifampicin + sulfamethoxazole-trimethoprim + protionamide and rifampicin + sulfamethoxazole-trimethoprim + isoniazid

Since 1970, when the lifelong monotherapy with dapsone (DDS) in leprosy could be replaced by short-term combination therapy with rifampicin + isoniazid + protionamide + DDS (Isoprodian-RMP), chemotherapeutic research was faced with two problems: (1) to find alternative treatment regimens for cases of intolerance, and (2) to work out forms of therapy allowing a further reduction of the average treatment time of 2 years. The present paper describes the attempts made to find solutions to these problems. With two new combinations, alternatives have become available, and the average treatment time is shortened to 6 months. Both combinations are also effective in tuberculosis.

Isoprodian and rifampicin in the treatment of leprosy: a descriptive evaluation of therapy durations in 475 Paraguayan leprosy patients

In Paraguay, the National Leprosy/Tuberculosis Program is based on a combined chemotherapy with isoprodian and rifampicin. The aim of this descriptive study was to investigate the therapy durations used so far in the treatment of 475 leprosy patients and to analyze the criteria responsible for the wide-ranging differences in therapy durations. As initial criteria, the following parameters were identified to have a significant influence on the therapy duration: Patients never treated before or pretreated, clinical classification and initial bacteriological index (BI) value. During therapy, conditions like the attendance and BI decrease/year showed a significant correlation with the therapy duration. Even though the studied criteria did not allow to draw a definite conclusion with regard to an 'ideal' therapy duration, they proved to be reliable, as only 2 patients have relapsed so far.

Comparison of a daily and three intermittent retreatment regimens for pulmonary tuberculosis administered under programme conditions

One daily and 3 thrice weekly retreatment regimens given for 12 months under programme conditions were compared. The daily regimen was rifampicin and ethambutol (RE7). The three intermittent regimens also contained rifampicin and ethambutol: one of them, rifampicin and ethambutol throughout (RE3); the next one supplemented with pyrazinamide for the first 3 months (REZ3); the last one supplemented with prothionamide for the first 3 months (REPt3). The pyrazinamide containing regimen was subdivided into ordinary and high dose groups. The subjects for retreatment were those who have had, at least, more than 6 months of initial triple chemotherapy of isoniazid, PAS and streptomycin at the health centres, and failed to convert to bacteriologically negative status. Among 419 patients who were available for sensitivity tests before commencing retreatment, 393 (94.3%) were resistant to isoniazid. Six hundred and seventy-four patients (674) were allocated randomly to the regimens: 64 patients were excluded due to various pretreatment reasons and 109 did not complete 12 months of chemotherapy. There remain 501 patients who completed their retreatment. As assessed at 12 months, a bacteriologically favourable response was achieved in 68% of 135 RE7 patients, 62% of 129 RE3 patients, 74% of 132 REZ3 patients, and in 79% of 108 REPt3 patients. Adverse reactions were uncommon: 4% in RE7, 5% in RE3 and 9% in REZ3, but 32% in REPt3. Relapse rates during 2 years after termination of chemotherapy were 15% in RE7, 14% in RE3 and REZ3, and 26% in REPt3, as calculated by life table analysis.

Activity of ofloxacin against Mycobacterium leprae in the mouse

Mice inoculated with 4800 Mycobacterium leprae in the left hind foot pad were treated from day 62 to day 150 after infection with 50 mg or 150 mg of ofloxacin per kg body weight, 150 mg pefloxacin per kg, or 50 mg prothionamide per kg. These drugs were administered by esophageal cannula 5 days weekly with dapsone (0.01 g per 100 g diet). Multiplication of M. leprae in the treated and in untreated control mice was assessed by monthly harvests. The treatment of mice with the smaller dosage ofloxacin, with pefloxacin, prothionamide, or dapsone uniformly resulted in a delay of multiplication of 4 months, compared to the multiplication of M. leprae in the untreated controls. The delay of multiplication (4 months) being 1 month longer than the duration of drug administration (3 months), all of the treatments may be considered as bacteriopausal or moderately bactericidal. In contast with these results, treatment of mice with 150 mg ofloxacin per kg resulted in no growth of the organisms whatever as late as 18 months after inoculation, strongly suggesting that, in that dosage, ofloxacin had killed all of the M. leprae. Such a profound killing activity has been observed only with rifampin. Although the pharmacokinetic characteristics of ofloxacin are different in man from those in the mouse, the daily dosage of 150 mg ofloxacin per kg body weight in the mouse is equivalent to 400 mg per day in man which is the usual therapeutic dosage; thus, the results obtained in the mouse may be extrapolated to man. Therefore, ofloxacin appears a very promising drug for the chemotherapy of leprosy.

Pulmonary tuberculosis treated with isoprodian and rifampicin or pyrazinamide

Three regimens of 9 months' duration, 2 containing Isoprodian (isoniazid, prothionamide and dapsone) and either rifampicin or pyrazinamide and the third, a former standard regimen, isoniazid, streptomycin and pyrazinamide, were allocated at random to 436 untreated African tuberculosis patients. In the course of the trial 83 were excluded for various reasons and 93 were lost. After 3 months of hospitalization, patients took either Isoprodian or isoniazid at home for 6 months and were then followed up for 24 months. The Isoprodian plus rifampicin regimen achieved 97% bacteriological cure, the Isoprodian plus pyrazinamide regimen 86% and the standard regimen 91%. Of 35 patients found to harbour drug-resistant strains 22 were cured. There were 15 relapses in all. Absconding was the most common cause of failure.

[5-year assessment of daily multi-drug therapy of leprosy in Guadeloupe since 1980]

In Guadeloupe, from January 1980 to December 1984, 420 leprosy patients were put under daily multidrug therapy: 10 mg/kg RMP plus 100 mg DDS during six months for paucibacillary patients, 10 mg/kg RMP plus 100 mg DDS during 24 months supplemented during the 12 first months with 10 mg/kg of a thioamide, ethionamide or protionamide, for multibacillary patients. The approval to the treatment was satisfactory in all the patients with active leprosy, new cases and relapse cases, less in the inactive patients already treated with dapsone only. The patients's compliance to treatment was satisfactory too. The lepra reactions were observed with a 19% frequency which is not different of the 15% frequency of lepra reactions observed in patients treated with DDS only. Hepatitis were observed only in multibacillary patients treated with PTH and RMP with a 14% frequency. Discontinuing treatment with RMP and PTH but not DDS resulted in recovery. When RMP was resumed without PTH, the hepatitis did not recur. All patients responded favorably under multidrug therapy and no relapse was observed among the 45 paucibacillary patients after a four year-surveillance and among the 16 multibacillary patients after a three year-surveillance.

Failure of a prothionamide-containing oral antituberculosis regimen

A group of 150 patients with sputum-positive pulmonary tuberculosis was treated with a regimen containing only orally administered drugs. Rifampicin and pyrazinamide were combined with Isoprodian, which contains isoniazid and also prothionamide and diaphenylsulphone. All the drugs were given daily for 5 months. Early analysis of the results shows 5 treatment failures, 27 relapses of pulmonary tuberculosis and another 17 patients who did not complete the prescribed regimen.

Comparative study of two regimens of combined chemotherapy of one year duration in multibacillary leprosy. Results after four and five years' follow-up

Two therapeutic regimens of one-year duration were administered to two groups of 20 previously untreated multibacillary leprosy patients. Regimen A was rifampin 600 mg twice weekly, prothionamide 500 mg, and dapsone (DDS) 100 mg daily for six months, followed by 100 mg DDS daily for another six months. Regimen B was identical to Regimen A but without prothionamide. Follow-up was for 4 1/2 and 5 years in 15 and 14 patients, respectively. Clinical improvement was rapid, and the bacterial index (BI) of the patients diminished by one unit per year after stopping treatment. Five patients were skin-smear negative at 54 months. The BI in the nasal mucosa became negative after 48 months. There were many attacks of erythema nodosum leprosum between month 3 of treatment until 13 and 21 months. Up to now no relapses have been observed. These results have confidence limits of 20% and 23%, respectively. However, when the results of the two regimens are added, the confidence limit for six months' twice weekly rifampin together with DDS and followed by six months of DDS and 4 1/2 years follow-up is 12%.

Treatment of leprosy--newer concepts

The latest time bound WHO regimens for the treatment of paucibacillary (I, TT, BT) and multibacillary leprosy is discussed. The rationale, indications of above regimens and cautions necessary are highlighted.

Multi-drug therapy in leprosy: an effective method of control

The steady increase in the prevalence of dapsone-resistant strains of leprosy threatens to undermine all the advances thus made for the control of this disease. Adoption of multidrug therapy, which can reverse this trend, is urgent.