|Year : 2000 | Volume
| Issue : 1 | Page : 18-25
Chemotherapy trials in MB leprosy using conventional and newer drugs pefloxacin and minocycline
Kiran Katoch, VM Katoch, M Natrajan, VD Sharma, Si
Source of Support: None, Conflict of Interest: None
One hundred, untreated, smear positive BB, BL and LL patients were treated with a regimen comprising of once a month, supervised, 600 mg of Rifampicin+ 400 mg Ofloxacin + 100 mg of Minocycline in addition to self administered 100 mg dapsone and 50 mg of clofazimine daily for twelve months.The treatment was then stopped and patients were followed up on placebo. This study reports the preliminary results after 2.5 to 3.5 years of post treatment follow-up. The drugs were well tolerated, the clinical response to the treatment was very good, and there was no case of treatment failure. Bacteriologically 25 out of the total 70 patients available for follow- up were still positive at the end of one year of treatment. These patients continued to progress satisfactorily and four patients were still positive at the end of 2 years. No growth was observed in the normal mouse foot pad after one year of therapy. No bacillary ATP was detected in the biopsy tissues after one year. While no M. leprae specific rRNA was detectable in any of the specimens after one year of treatment, weak PCR signals were detectable in 3/57 specimens at that period. In the follow up available no patient has relapsed. The patients are being followed up on placebo and longer follow-up is required to draw firm conclusions.
Keywords: Leprosy, Treatment, ROM regime
|How to cite this article:|
Katoch K, Katoch V M, Natrajan M, Sharma V D, Si. Chemotherapy trials in MB leprosy using conventional and newer drugs pefloxacin and minocycline. Indian J Dermatol Venereol Leprol 2000;66:18-25
|How to cite this URL:|
Katoch K, Katoch V M, Natrajan M, Sharma V D, Si. Chemotherapy trials in MB leprosy using conventional and newer drugs pefloxacin and minocycline. Indian J Dermatol Venereol Leprol [serial online] 2000 [cited 2020 Nov 29];66:18-25. Available from: https://www.ijdvl.com/text.asp?2000/66/1/18/4854
| Introduction|| |
In the last three decades, rapid advances have been made in the treatment and management of leprosy. More effective regimens are now available and the treatment has been shortened considerably but still some problems do remain. The relapse rate in MB patients with the standard WHO recommended MDT (WHO 1982) is negligible, but the time taken for achieving bacteriological negativity ranges from 2 to 6 years depending on the bacterial load of the patients. In order to cut short the duration of treatment the WHO advocated that the treatment be stopped after 2 years in all the patients regardless of their bacteriological status. They hypothesized that this much duration of treatment will kill most of the bacteria and also take care of the drug resistant strains. When highly bacillated MB patients, treated with two years MDT, were followed up for about 3 years after stopping therapy the patients appeared to be responding well,  but when the duration of follow-up increased to 7 to 9 years, the relapse increased to upto 20% in these patients.  Furthermore none of these relapsed patients suffered from drug resistant disease. It can therefore be inferred that there are a sub group of MB patients who relapse with fixed duration MDT of 2 years, and require prolonged therapy. Although the number of these patients requiring therapy has decreased tremendously, a substantial number of patients still remain and require prolonged treatment. Several potent newer drugs for the treatment of leprosy are now available. Both ofloxacins and minocycline ,are potent bactericidal drugs and have been tested in animals and in humans. However their effect as monthly supervised doses in combination with the standard WHO therapy for limited duration has not been assessed. In the present study an attempt has been made to see the effect of this combination in multibacillary patients and also if the addition of these to the treatment regimen could help in effectively reducing the duration of therapy.
| Patients and Methods|| |
One hundred, untreated or less than 3 months treated positive BB, BL and LL patients between the age group of 16 to 60 years who consented to be a part of the study group were included in the study. After obtaining their written consent, the patients were thoroughly examined, details charted on the body chart, clinical score noted,  smears taken from four standard sites and the result recorded. A skin tissue biopsy was taken from an active site and processed for routine histopathology, mouse foot pad inoculation,  ATP estimation,  detection of r RNA of M leprae andPCR. 
These patients were then treated with a regimen comprising of twelve supervised doses of once a month 600 mgs of Rifampicin +100 mgs of Minocyline +400 mgs of Ofloxacin combined with 50 mgs of clofazimine and 100 mgs of dapsone daily for one year. The patients had to complete the schedule in a maximum period of 18 months. After completion of therapy it is envisaged to follow up the patients on placebo for 8 to 10 years.
During the treatment phase the patients reported every month. They were physically examined, their clinical details recorded, any adverse effect noted and then administered the supervised doses. The daily medicines were given for taking at home and advised to come after one month for the supervised dose. However, they were advised to report immediately if there was any adverse effect. After completion of twelve such cycles of treatment, the patients were again thoroughly examined and the details recorded in the body chart, clinical score calculated and noted. Their smears were retested from the same sites as was done earlier and recorded. Skin tissue biopsy was taken from the same site as was done previously and again sent for histopathology, mouse foot pad inoculation, ATP estimation and detection of nucleic acid by the same methods as referred to earlier.The patients were now given a placebo daily and advised to come every 3 to 6 months or earlier if there was any problem. The following parameters were used for assessing the outcome in the present study.
| Treatment failure|| |
The clinical criteria usd for the definition of treatment failure were the appearance of new lesions and/ or a definite worsening of existing lesions not related to or accompanied by reversal reactions. Bateriologically it should be associated with an increase in average BI by more than one unit from the inital average BI. Additionally a rise in the bacillary ATP levels as compared to the initial levels would be considered as supporting evidence.
| Relapse|| |
Relapse is to be suspected if there is an average BI increase of more than one unit from the value at the time of completion of treatment, at any site with the appearance of new lesions or definite worsening of existing lesions. An increase in bacillary ATP levels and/or positive mouse foot pad result would be taken as additional confirmatory evidence.
| Results|| |
Of the total one hundred patients included in the study, there were 15 LL, 35 BL, and 501313 patients. Of these there were 17 female and 83 male patients. Seventy patients (57 males, 13 females) completed the treatment phase and the subsequent follow-up of two to three years [Table - 1]
All the patients tolerated the drugs well. Only 2 patients had nausea after taking the supervised dose. In none of them the treatment had to be suspended due to these symptoms. One patient had jaundice during treatment (3rd month), and treatment was temporarily stopped. After recovery from hepatitis the treatment was restarted and there was no recurrence of the symptoms. He probably had an attack of infective hepatitis which regressed susbsequently and was unrelated to the treatment.
Twenty-three patients gave history of lepra reactions before starting treatment. In 16 patients there were episodes of both type 1 and 2 reactions (9 patients had ENL and 7 patients had reversal reaction) during treatment. They all responded to anti- reaction therapy consisting of the required doses of steroids which were gradually tapered off, and in no case the treatment had to be stopped due to the reactions. After stoppage of treatment four patients continued to have ENL reactions. These patients are being treated with steroids in addition to the placebo and are being fololwed up. Neuritis was present as a part of ENL and or reversal reaction and in no case neuritis alone was present.
| Clinical progress|| |
The clinical response of patients to the treatment was very good. The lesions started regressing, erythema subsided and the lesions became wrinkled in a few months. The infiltration also regressed gradually and was slowly replaced by wrinkling of the skin. For assessing the clinical response of the patients by measurement of the clinical score the patients have been divided into three depending on their clinical classificatoin [Table - 2]. In the LL group the clinical score decreased from an average of 16 at the start of therapy to an average of 8 at the time of stoppage of treatment. In the BL group this decreased from an initial 14 to 7, and in the BB group this fell from an intial 10 to 4 at the time of completion of treatment. No case of treatment failure was observed.
| Bacteriological progress|| |
The bacteriological response of the patients to treatment was also very good. While all patients were smear positive at the beginning of treatment (range 4+ to 1+), at the time of completion of treatment i.e at the end of one year, 25 patients were still positive. After 2 to 3 years, 70 patients were available for follow-up. The bacteriological progress of these patients is given in [Table - 3]. For detailed analysis these patients have been further subdivided into 5 subgroups depending on their BI status.
(a) As is observed, from the table, 8 patients were available for follow-up from the first sub-group. Their average BI at the start of treatment was 4.4 (range 4 to 5+). None of these patients became smear negative at the end of one year of treatment and the average BI at this time was 2.30. Treatment in all these patients was stopped and they were followed up on placebo. Three patients from this group continued to have ENL reaction while on placebo and were treated with steroids in addition to the placebo. Six patients from this sub-group became smear negative by the end of two years. The average BI was 0.64. Two patients from this group continued to have ENL in the second year also and were treated with steroids. At the end of three years one more patient i.e. 7 patients have become smear negative. The 8th patient has not completed the three years and is due for follow-up soon. By three years the ENL reaction had subsided in all of the patients.
(b) In the second sub-group the BI ranged from 3 to 3.9+. Seven patients from this sub-group were available for follow-up. None of the patients from this sub-group became negative after one year of therapy, when treatment was stopped. The average BI at the time of stopping treatment was 1.4. Treatment in all these patients was stopped and they continued on placebo. One patient from this group continued to have ENL after stopping treatment and was treated with steroids in addition to the placebo. By the end of second year, 5 patients became smear negative while 2 patients continued to be smear positive. In one of these patients there was no fall in the BI in this year. The average BI at the end of this period was 0.2 and one patients continued to have ENL at this time also. In the third year a fall in BI was observed in the above patient who did not register a fall in BI in the second year.
(C) Thirteen patients were available for follow-up who had an average BI of 2.25 (range 2 to 2.9). By the end of one year, 4 of these patients became smear negative. The rest of the 9 patients had very few bacilli in their skin and the average BI was 0.27. No patient in this sub-group suffered from any reaction after stoppage of therapy. The lesions regressed in these patients and all of them became smear negative by two years. They are all being followed up.
(d) In the sub- group of patients who had an average BI of 1.28 (range 1 to 1.9), 17 patients were available for follow-up. By the end of one year, 16 of these patients became smear negative. Only one patient was smear positive, and had a reversal reaction. He responded to steroids and continued on placebo. He became smear negative by the end of the second year. All other patients progressed well and continued on placebo.
(e) Twenty-five patients were available who had smear positivity at one or more lesions in the body and had an average BI of 0.55 at the start of therapy. All these patients became smear negative by the end of one year. Their lesions have regressed and all of them are being followed on placebo. In none of them there was any worsening of the disease in the follow-up period.
| Viability assessment|| |
The number of viable bacilli in these patients were estimated by inoculation of skin tissue biopsies from all of these patients into foot pads of normal mice and harvesting them as described by Desikan and Venkatraman,  and also by estimating the ATP content of the bacilli from the tissue biopsies at the start of therapy and at the end of one year when the treatment was stopped. These results are being published separately. To summarise the results are as follows. There was growth in the mouse foot pads in 40% of the cases at the start of treatment and no growth observed in any of the specimens after completion of treatment. Bacillary ATP was detectable in 100% of the patients at the start of therapy. Bacillary ATP content exhibited a large range with most of the specimens having a low ATP content, as expected, as the BI of the patients varied from 1 to 4+. However no bacillary ATP was detectable in any of the biopsy specimens at the end of one year of treatment.
| Gene probes and Gene amplification|| |
All the 95 patients tested with rRNA targetting probes tested positive at the start of therapy. While all the specimens were positive for PCR at the beginning of treatment, at the end of one year 3 of the 57 samples tested showed weak PCR signals.  Weak PCR signals were detectable in the tissue of 2 of the 4 bacteriological positive patients at the end of 2 years.
| Discussion|| |
The WHO recommended MDT has considerably shortened the duration of treatment of leprosy. Recently in a bid to eradicate leprosy by the year 2000 certain new recommendations have been made which include stoppage of therapy in MB cases after completion of one year of standard recommended therapy.  Unfortunately these recommendations are not based on appropriate trials with a sufficient duration of follow-up. As already reported by the Marchoux chemotherapy group, these MB patients have to be followed over a sufficient length of time to ascertain the actual relapse rate. In that trial when the post treatment follow-up was upto 27 months, the relapse rate was 2% but when the follow-up period increased to 72 months after completion of two years of MDT, 20% relapses were observed.
Several potent drugs are now available and are being used for treatment of the disease, it is now being hoped that the duration of treatment can be effectively shortened with the addition of these drugs to the treatment regimens.
Gelber et al,  studied the activity of combination of dapsone, rifampin, minocycline, clarithromycin and sparfloxacin against M leprae infected mice. They reported that the combination of the antileprosy drugs were generally additive. Ji et al sub studied the bactericidal activity of a single dose combination of ofloxacin plus minocycline, with or without rifampin against M leprae in mice and in lepromatous leprosy patients. They observed that RFM-OFLO- MINO combination was well tolerated and definite bactericidal activity was observed. In the present study also the combination of supervised doses of rifampicin plus minocycline plus ofloxacin with daily dapsone and clofazimine is well tolerated and does not have any undue side effects. It also has added advantage of easy administration in the field. The clinical response of the patients to this regimen was also very good. At the end of one year of treatment the erythema in the lesions had subsided and there was wrinkling in the skin. No case of treatment failure was observed. Twenty-three percent of patients gave history of reaction even before the treatment was started. They all responded to the anti reaction treatment which was given in addition to the treatment regimen. After stoppage of therapy 4 patients continued to have ENL reaction. They were all treated for the reaction with steroids while continuing on placebo. Neuritis was observed as a part of reaction, and in no case only neuritis was observed. One patient had reversal reaction after stoppage of therapy. He also responded to steroids while continuing on placebo. No patient developed deformity during treatment or during the follow-up.
Bacteriologically also the response to treatment was very good. At the beginning of treatment all patients were smear positive (4 to 1+). As this is a very big range, for analysis of data they have been divided into five sub-groups depending on their smear status, as detailed in [Table - 3] and discussed above. Of the 70 patients who were available for follow-up, 25 were smear positive at the end of treatment schedule ie.one year. [Table 4]. Two years after stoppage of therapy, 4 patients continued to be smear positive. Subsequently in the follow-up available 3 of these patients have become smear negative. If these patients are re-grouped into groups i.e one group with a BI of 2+ and more and another with a BI of less than 2+, it is observed that 28 patients belonged to the first group and 42 to the latter group. In the first group 24 patients were still smear positive at the time of stoppage of therapy (average BI 1.23), out of which 20 became negative after a follow-up of one year. In the second group out of the total 42 patients all except one patient became smear negative during the treatment phase of one year. This is a very rapid fall compared to what was observed earlier with the standard WHO therapy.,,The mean fall in BI with the regimen as reported by various authors was about 1 log per year. After the widespread use of MDT, the profile of patients now presenting have undergone a change. ,This could be one of the reasons of better response in the present study. The addition of two potent bactericidal drugs to the treatment schedule has also helped in achieving this result.
By the addition of two potent bactericidal drugs it was envisaged that there would be more rapid killing of viable bacilli. Bacilli from tissue biopsy specimens were inoculated into foot pads of normal mice at the start of therapy and after one year at the completion of the treatment schedule. While growth was observed in 40% of specimens at the start of therapy no growth was observed in any of the patients at the completion of therapy. The ATP content of the bacilli was also estimated in the tissue biopsies. While bacillary ATP was detected in 100% of the patients at the start of therapy, no bacillary ATP was detectable in any of the biopsy specimens at the end of one year of treatment. In the earlier studies viability assessments were done at the beginning of treatment and at the end of 2 years, which was then considered the optimum duration. Viable persisters were detected in 9 to 16% of the cases by using various methods., Only a few reports are available on the viability parameters at the end of one year of treatment. However limited experience is available from our earlier studies.,It was observed that out of the 8 patients who were on the slightly modified WHO regimen, (the only difference from the WHO regimen was that in this regimen 300mgs of supervised dosage of monthly clofazimine was not administered, but the patient did receive the daily dosage of clofazimine) there was growth on inoculation of bacilli from tissue biopsies in the mouse footpad in one patient and bacillary ATP was detectable in the tissue biopsies of 2 patients after one year of treatment. In an another study we tried to retrieve the highly bacillated patients who had stopped treatment (MDT) after varying duration of therapy and assessed them. It was observed that all the retrieved patients who had stopped treatment after 12 to 18 months of therapy worsened clinically and bacteriologically, and high levels of bacillary ATP was detectable in their tissue biopsies which was tested 4 to 5 years after stoppage of therapy. In the present study no bacillary ATP was detected at the end of one year of therapy. However these patients of the present study need to be retested after sufficient duration of follow-up to draw firm conclusions.
At the start of therapy, positive signals with rRNA targetting probes and PCR were observed in all the 95 patients studied. The effect of the bactericidal efficacy of this regimen used in this study is further confirmed by the absence of any detectable rRNA signals at the end of one year of treatment. Somewhat similar trends were observed with PCR using 36kDa gene. After 1 year of therapy weak signals were observed in 3 of the 57 patient's tissue biopsy samples.These signals persisted even at 2 years in 2 of the 4 specimens who were smear positive at this time period. Although there is not much experience in the use of PCR for the assessment of viability, it has been used by some workers for this purpose.This will have to be repeated in patients after a sufficient follow-up for correlation with other viability parameters.
To conclude, this regimen is well tolerated, safe, does not induce or increase the incidence of reactions and can be easily administered in the field.The patients improved clinically and bacteriologically and this was more than what was seen with the WHO recommended MDT used earlier.As the profile of presentation of leprosy has changed since the introduction of MDT two and a half decades earlier, these patients need to be compared to those patients who are undergoing the earlier WHO recommended MDT now, to observe the difference in response to the addition of two more bactericidal agents. These patients also need to be followed up for a longer period to find out the incidence of relapses in these patients.
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[Table - 1], [Table - 2], [Table - 3], [Table - 4]