Clarithromycin vs ciprofloxacin as adjuncts to rifampicin and ethambutol in treating opportunist mycobacterial lung diseases and an assessment of Mycobacterium vaccae immunotherapy
- 1Mycobacterium Reference Laboratory, Cardiff, UK
- 2Llandough Hospital, Penarth, UK
- 3Singleton Hospital, Swansea, UK
- 4Department of Medical Statistics, Edinburgh University, Edinburgh, UK
- Dr I A Campbell, Llandough Hospital, Penarth CF64 5SD, UK;
- Received 30 July 2007
- Accepted 9 January 2008
- Published Online First 4 February 2008
Background: The mainstays of treatment for pulmonary disease caused by opportunist mycobacteria are rifampicin (R) and ethambutol (E). The role of macrolides, quinolones and immunotherapy with Mycobacterium vaccae is not clear. A trial was undertaken to compare clarithromycin (Clari) and ciprofloxacin (Cipro) as third drugs added after 2 years of treatment with R and E for pulmonary disease caused by M avium-intracellulare (MAC), M malmoense and M xenopi (REClari and RECipro). An optional comparison of immunotherapy with M vaccae vs no immunotherapy was also performed.
Methods: Progress was monitored annually during the 2 years of treatment and for 3 years thereafter. If the patient was not improving at 1 year the regimen was supplemented by the addition of the drug not received in the original allocation of treatment.
Results: 371 patients (186 REClari, 185 RECipro) entered the study (170 MAC, 167 M malmoense, 34 M xenopi). All-cause mortality was high for both groups (44% REClari, 43% RECipro); for MAC it was higher with REClari than with RECipro (48% vs 29%) but for M malmoense (42% vs 56%) and M xenopi (29% vs 47%) it was higher with RECipro (p = 0.006). 3% died from their mycobacterial disease (REClari = RECipro). At the end of treatment, 4% of REClari and 10% of RECipro patients still had positive cultures. Among those with negative cultures at the end of treatment, 6% of the REClari group and 4% of the RECipro group had relapsed. At 5 years 30% of the REClari group were known to have completed treatment as allocated and to be alive and cured compared with 21% of the RECipro group (p = 0.04), but this difference was principally due to those with M malmoense (REClari 38%, RECipro 20%). Patients with MAC or M xenopi were more likely to have a poor outcome than those with M malmoense (p = 0.004), with no difference between REClari and RECipro. Overall, 20% in each group were unable to tolerate the regimen allocated, Cipro being associated with more unwanted effects than Clari (16% vs 9%, p = 0.05). No significant differences in outcomes were found between M vaccae-treated patients and those not treated with M vaccae immunotherapy.
Conclusion: Considering all three species together, there were no differences in outcome between the REClari and RECipro groups. Immunotherapy did not improve outcome. New therapies, optimised management of co-morbid conditions and a more holistic approach must be explored in the hope of improving outcome.
Funding: This study was funded by grants to the Research Committee of the British Thoracic Society from Abbott Laboratories and Bayer Laboratories.
Competing interests: None.
Contributors: The first draft of the protocol was written by IAC and modified after discussion by the subcommittee. Data entry was overseen by IAC. RJP supervised data checking and performed the statistical analyses. The first draft of the report was produced by IAC, who made amendments in the light of discussion and comment by the subcommittee. The penultimate draft was scrutinised by the Research Committee and the final version then prepared by IAC.