Pharmacokinetics and relative bioavailability of clofazimine in relation to food, orange juice and antacid.

BACKGROUND: Clofazimine is potentially useful for the treatment of disease due to multidrug resistant Mycobacterium tuberculosis, as well as leprosy and certain chronic skin diseases. Its pharmacokinetics have been incompletely characterized. This study was conducted to explore issues relating to bioavailability in the presence of food, orange juice, and antacid. METHODS: A 5 drug regimen consisting of clofazimine, cycloserine, ethionamide, para-aminosalicyclic acid, and pyridoxime was administered to healthy subjects four times using a four period cross-over design with two weeks washout between treatments. Subjects also received orange juice, a high fat meal, aluminum/magnesium antacid, or only water in random order with the drug regimen. The pharmacokinetics of clofazimine were assessed using individual- and population-based methods and relative bioavailability compared to fasting administration was determined. RESULTS: Clofazimine exhibited a sometimes prolonged and variable lag-time and considerable variability in plasma concentrations. From the population analysis (one-compartment model), the mean oral clearance was 76.7 l/h (CV=74.2%) and mean apparent volume of distribution was 1470 l (CV=36.3%). The first-order absorption rate constant ranged from 0.716 to 1.33 h(-1) (pooled CV=61.7%). Residual (proportional) error was 49.1%. Estimates of bioavailability compared to fasting administration were 145% (90% CI, 107-183%) for administration with high fat food, 82.0% (63.2-101%) for administration with orange juice, and 78.5% (55.1-102%) for administration with antacid. CONCLUSION: Administration of clofazimine with a high fat meal provides the greatest bioavailability, however, bioavailability is associated with high inter- and intra-subject variability. Both orange juice and aluminum-magnesium antacid produced a reduction in mean bioavailability of clofazimine.

Daily multidrug therapy for leprosy; results of a fourteen-year experience.

Between 1980 and 1994, 67 new or relapsing leprosy patients were treated by daily administered multidrug regimens. Tuberculoid patients (23 TT/BT) received either bitherapy [rifampin + dapsone or clofazimine (RMP + DDS or CLO)] or tritherapy [RMP + DDS and/or CLO and/or ethionamide (ETH)] until clinical cure. Lepromatous patients (44 BB/BL/LL) received tritherapy (RMP + DDS and/or CLO and/or ETH) at least until bacteriological negativity. Of the 23 tuberculoid patients only one patient (5%) was cured at 6 months and about 70% needed between 6 and 24 months of treatment to obtain clinical cure (mean 19.5 months). In the 44 lepromatous patients, the achievement of bacteriological negativity was significantly linked to the initial bacterial index (BI), and it occurred after 2 to 7 years (mean 66.5 months) of multidrug therapy (MDT). The average BI decrease per year was 1.1+ during the first year, 0.9+ the second year, and then < 0.5+ per year. Reactional states significantly (p < 0.01) influenced the BI course: reversal reactions (RR) accelerated while erythema nodosum leprosum (ENL) delayed the BI decrease. Three of the 23 (13%) tuberculoid and 19 of the 44 (43%) lepromatous patients (p < 0.02) exhibited a RR and 18 of 44 (41%) lepromatous patients had ENL during MDT. A late RR (LRR) was observed in 1 (5%) and 6 (17%) of our tuberculoid and lepromatous patients, respectively, and 3 (8%) of our lepromatous patients suffered post-MDT ENL. No confirmed relapse has been observed within a follow-up period of 6 months to 7 years and 3 months [59 person-years at risk (PYR)] for TT/BT patients and of 4 months to 5 years and 10 months (100 PYR) for BB/BL/LL patients. When compared to the recommended WHO/MDT, it appears that daily MDT does not increase the clinical or the bacteriological cure rates either at 6 months in paucibacillary tuberculoid patients or at 2d years in multibacillary lepromatous patients. Moreover, as does the WHO/MDT, our regimens show a high frequency of reactional states both during and after treatment. This fact constitutes the main new problem of the actual treatment of leprosy.

A randomized clinical trial of two single-dose treatments for paucibacillary leprosy.

We compared 2 single-dose regimens for the treatment of paucibacillary leprosy in a randomized clinical trial in Zaïre. The regimens were: C2 (rifampicin 40 mg/kg and 1200 mg clofazimine once) and C4 (rifampicin 40 mg/kg, clofazimine 100 mg, DDS 100 mg and ethionamide 500 mg once). An analysis of the results of patients enrolled between May 1987 and December 1988, with a maximum follow-up of 4 years, is presented. A total of 622 patients were enrolled and 14 paucibacillary and 1 multibacillary relapses occurred. The overall paucibacillary relapse rate was 2.4 per 100 person years. This relapse rate was higher for older patients as well as for patients with 3 or more lesions. The probability of cure at 3 years is 0.816 for C2 and 0.823 for C4, the difference not being statistically significant. The probability of cure at 3 years with either regimen is higher for patients with 1 or 2 lesions (0.872) than for patients with 3 or more lesions (0.787), and it is higher for patients with a bacterial index of 0 (0.831) than for patients with a bacterial index of 1 (0.699). These results are compared to other studies. We also discuss the potential of single-dose treatment regimens for paucibacillary leprosy.

Leprosy in French Polynesia. The possible impact of multidrug therapy on epidemiological trends.

In 1982, following the recommendations of a WHO study group, multidrug therapy (MDT) was introduced into French Polynesia to treat all patients suffering from active leprosy, and--only on request--those still on dapsone monotherapy. After 5 years, a clear-cut decrease of prevalence and mean annual detection rates for leprosy (except for detection rates among children aged less than 15 years, many of such cases being detected early by increased household contact training) has been observed. There was also a decrease in the proportion of newly detected cases with disabilities. During the 21-year period preceding the introduction of MDT into the control programme, mean annual detection rates for leprosy had remained stable, and this led to the consideration that such a decrease was due neither to the natural decline of the disease nor to the economic improvement of the country. Our results, together with the fact that, to date, the relapse rate was nil in the Polynesian patients put on MDT, strongly suggest that the implementation of MDT has resulted in a decrease of detection rates for leprosy which may be a consequence of a decrease in the transmission of the disease.

Ambulatory treatment of multibacillary leprosy with a regimen of 8 months duration.

An ambulatory treatment regimen for multibacillary leprosy, of 34 weeks duration composed of 8 weeks daily supervised rifampicin, ethionamide (ETH), dapsone (DDS) and clofazimine (CLO) followed by 26 weeks of unsupervised ETH, DDS and CLO, introduced in 1983 has been evaluated; 268 patients were followed for a mean of 4.4 years and a total of 1188 patient years. The relapse rate was 0.33 per 100 patient years of follow up. The reduction of the duration of the combined administration of RMP + ETH reduced the hepatotoxicity to 1.4%. It is possible that both phases of the regimen studied could still be reduced, however, in the near future ETH will be replaced by alternative bactericidal drugs, avoiding the hepatotoxicity.

Treatment of multibacillary leprosy with a regimen of 13 weeks duration.

In a prospective study 559 multibacillary patients in Zaire were treated for 13 weeks with twice weekly rifampicin (600 mg) and daily ethionamide (500 mg) and dapsone (100 mg), 13-RED, or clofazimine (100 mg), 13-REC. The patients were followed for a total of 1418 person years, mean 3.2 years. The incidence of hepatitis was 3.3%. The incidence of relapses was 0.28 per 100 person years. Relapses were due to drug-sensitive organisms. In patients who received the same drug regimens but with a reduced dosage of ethionamide to 5 mg/k bodyweight, the incidence of hepatitis was significantly lower but the relapse rate was 7.8 per 100 person years of follow-up in the RED group, no relapses were diagnosed in the REC group. It is concluded that by the use of potent antileprosy drugs in suitable combinations and dosages, it will be possible to shorten the duration of antibacterial treatment in multibacillary leprosy to 3 months.

[Acute uveitis in reversal reactions]. / Uvéites aiguës au cours des réactions de réversion.

Two cases of acute uveitis have been reported in reversal reactions in lepromatous patients treated with anti-hansenian multidrug therapy with daily rifampicin. This type of eye damage has seldom been reported in reversal reactions.

[Late reversal reactions in leprosy]. / Les réactions de réversion tardives au cours de la lèpre.

Since the application of short duration multidrug therapy (MDT) in leprosy, it has been reported that reversal reactions (RR) may occur after withdrawal of treatment. Surprisingly, such "late reversal reactions" have quite never been described after monosulphonotherapy. Such RR, especially in endemic areas, may represent diagnostic and therapeutic difficult problems. We report 5 cases of late RR. In 4 cases (1 BT patient and 3 BL-LLs patients), the RR occurred 1 month 1/2 to 3 years after cessation of MDT. In the last case (form LLs), the RR happened 6 months after that a 14 years monosulphonotherapy has been stopped. These observations strengthen the need of a complete clinical, bacteriological and immunological evaluation at the time of the diagnostic, more useful than a single bacteriological study, to differentiate late RR from relapses. Moreover, the last case confirms that late RR may occur after monosulphonotherapy.

Combined regimens of one year duration in the treatment of multibacillary leprosy--I. Combined regimens with rifampicin administered during one year.

In 1981, 1982 and 1983, 216 multibacillary patients in Anjouan (Comores) and Burundi were treated for 8 weeks with daily rifampicin (600 mg) ethionamide (500 mg) and dapsone (100 mg) or clofazimine (100 mg) followed for 44 weeks by once weekly rifampicin (600 mg) and daily ethionamide (500 mg) and dapsone (100 mg) or clofazimine (100 mg). There were 109 previously untreated patients and 107 patients who had dapsone monotherapy, 16 of whom were infected with proven dapsone resistant Mycobacterium leprae. Clinical and bacteriological results were excellent but hepatotoxicity of this regimen remains a problem. No relapses were observed during a 2 to 6 years (mean: 4.29 years) follow-up period after the end of treatment (upper 95% confidence limit of 0.40 per 100 persons years). It is concluded that multibacillary leprosy can be successfully treated with a regimen of one year duration, but less toxic regimens, more easily applicable in the field, are necessary.

Combined regimens of one year duration in the treatment of multibacillary leprosy--II. Combined regimens with rifampicin administered during 6 months.

From 1981 to 1983 all multibacillary patients presenting at the collaborating centres in Zaire and Rwanda were treated with one of the following regimens: 6 months supervised daily RMP 600 mg, ETH 500 mg and DDS 100 mg or CLO 100 mg followed by 6 months unsupervised daily DDS 100 mg or CLO 100 mg with ETH 500 mg added or not. These regimens gave rise to hepatotoxicity, reversal and erythema nodosum leprosum reactions as described previously. Bactericidal activity was excellent. Among the 289 patients in the trial, with a mean follow-up period of 3.88 years, no relapses were observed, with an upper 95% confidence limit of 0.35 per 100 person years. Because of the hepatotoxicity, alternative short-course therapies need to be tested.

[Supervised bimonthly quadruple chemotherapy in 72 paucibacillary leprosy patients in French Guyana]. / Quadruple chimiothérapie bimensuelle supervisée chez 72 paucibacillaires en Guyane française.

In French Guyana we have treated 72 paucibacillary leprosy with an association of Rifadine + Lamprene + Trecator + Disulone given twice monthly under supervision during 6 months. Results have been satisfying and side effects rare. The sequential character of treatment shows a substantial advantage on the operational side but may appear to be favorable to bacterial resistance.

Feasibility of multidrug therapy (MDT) in Hansen's disease in an urban population--Curupaiti State Hospital, Rio de Janeiro, Brazil.

The acceptance of the WHO regimen in a group of 220 patients was approximately 84.5%. Only 11% abandoned the treatment, and the substitution of ethionamide or prothionamide for clofazimine due to excessive hyperpigmentation was necessary in only eight cases. The WHO regimens adopted provided a more frequent (monthly) relationship between the patients and their health service. It was necessary to: a) reorganize the technical-administrative infrastructure, with the intention of providing an improved service to the patients for treatment and control; and b) pay more attention to the problem of deformities and health education activities. As for the side effects of the drugs, 54 patients showed alterations in their liver function tests, which were usually mild and which resolved despite continuation of the treatment. Of the reactional episodes observed during MDT, it would not appear that the therapeutic regimens contributed to their occurrence or aggravation.

Short term combination therapy for paucibacillary leprosy--histological evaluation & follow-up study.

68 patients with paucibacillary disease were started on various regimes of multi drug therapy, consisting of ethionamide, rifampicin or clofazimine administered with dapsone. Serial skin biopsies were taken from 32 patients at one, two and three years and even later after the initial pre treatment biopsy. Actual material was available for study from 9 patients. All regimens were tolerated well except the one with ethionamide. However the therapeutic response was equal in all combination therapies as supported by histopathology. Compared to that with dapsone monotherapy the response was quicker with combination. Dapsone plus rifampicin combination was best tolerated and it worked out to be economical as well. No relapse was noted in any group during two or more years follow up.

Prospective study on the relationship between intensive bactericidal therapy and leprosy reactions.

A systematic study was performed on the reactions occurring during several short-course therapy regimens for the treatment of paucibacillary and multibacillary patients. Most type 1 upgrading reactions in paucibacillary (PB) leprosy were mild to moderate and of short duration, while the time of onset was extremely variable. Their incidence was higher in the regimen rifampin (RMP) 900 mg once weekly for ten weeks than when a single dose of RMP 40 mg/kg body weight was given or 1500 mg in one dose followed by one year of dapsone (DDS) 100 mg daily. In multibacillary (MB) leprosy, three regimens were compared: MB-WHO regimen; regimen C, consisting of daily RMP 600 mg, ethionamide (ETH) 500 mg, and DDS or clofazimine (CLO) 100 mg for six months, followed by six months of daily DDS or CLO; and regimen D, identical to regimen C but comprising daily DDS or CLO plus ETH 500 mg during the second semester. Type 1 upgrading reactions occurred more frequently in MB patients and were more severe than in PB patients. They occurred more frequently and were more severe in regimens C and D than in the MB-WHO regimen. CLO 100 mg daily prevented type 1 reactions in MB patients and rendered them less severe. ENL was also more frequent in regimens C and D and was not prevented by CLO in the dosage used. Although there is some correlation between type 1 reactions and the total amount of RMP administered, other aspects of RMP administration.(ABSTRACT TRUNCATED AT 250 WORDS)

[A trial of polychemotherapy of leprosy in the Dakar region. Initial observations on the acceptability of the protocols used]. / Présentation d'un essai de polychimiothérapie de la lèpre dans la région de Dakar. Premières observations sur l'acceptabilité des protocoles utilisés.

Since 1982, in Dakar, a controlled essay tests the suitability of several short protocols of multidrug therapy (MDT), some of them being close to those advised by the WHO, others showing a starter stage of a two month daily MDT. In three years, 198 paucibacillary and 123 multibacillary patients have been treated. The short duration of these treatments leads to an important decrease in the load of the Department. The total rate of those who have not attended for the treatment is of 15.2% whereas it was of 52% with DDS monotherapy for a similar treatment duration. Those who gave up don't seem to live in Dakar. To judge by the diligence of the patients, the compliance seems excellent even for the protocols requiring a daily dose of ethionamide: 95% of paucibacillary, 76% of multibacillary patients have maximal attendance. The authors think that any MDT program: must be preceded by a retraining of staffs; must give a priority to the health education of the patients; must involve a home patient search for system.