Rationale:
Treatment of multidrug or extensively drug resistant tuberculosis (MDR/XDR-TB) is a real
challenge as failure in response to treatment and serious side-effects are frequently
encountered. New, more effective drugs with less side effects are therefore urgently needed
to solve this problem. Although several new drugs against TB are in the pipeline, physicians
currently have limited treatment options for treatment of complicated MDR/XDR-TB cases.
Therefore, drugs developed and labeled for other infectious diseases are evaluated for TB.
Co-trimoxazole consists of sulfamethoxazole and trimethoprim. Sulfamethoxazole could be
effective in the treatment of tuberculosis as shown by Forgacs et al. and Huang et al.
Furthermore, with dried blood spot (DBS) analysis, the exposure to co-trimoxazole could be
analyzed with only some blood drops withdrawn with a finger prick on paper. This paper is
suitable for storage, transportation and subsequently analysis without additional cooling or
storage requirements.
Objective:
The main objective of this prospective clinical trial is to evaluate pharmacokinetics of 960
mg co-trimoxazole in TB patients. This clinical trial will provide important information on
PK of co-trimoxazole in TB patients for future studies.
The second objective is to calculate the T>MIC and AUC0-24h/Minimal inhibitory concentration
(MIC) ratio as efficacy predicting parameter. Furthermore, the analysis of dried blood spots
will be clinically validated by comparing results of blood samples withdrawn from venous
blood versus withdrawn by finger prick and transferred to filter paper. Retrospectively, data
from this study can be used for limited sampling strategies for co-trimoxazole based on a
pharmacokinetic population model constructed from the full PK curves of the patients.
Study design:
A prospective pharmacokinetic study.
Study population: 12 TB patients.
Intervention: on 4 to 6 days, 960 mg co-trimoxazole daily will be added to the normal
treatment regimen.
Main study parameters/endpoints:
The pharmacokinetic parameters (Vd, Cl, AUC, etc) of co-trimoxazole are the primary endpoints
of the study. The T>MIC and AUC0-24h/Minimal inhibitory concentration (MIC) ratio are most
likely the best predictive parameters for efficacy of co-trimoxazole treatment and will be
calculated for a range of M tuberculosis isolates.
Phase:
Phase 2
Details
Lead Sponsor:
University Medical Center Groningen
Treatments:
Sulfamethoxazole Trimethoprim Trimethoprim, Sulfamethoxazole Drug Combination