Related Experiment Videos
Proposals for concomitant use of several modulators of multidrug resistance in clinics
1Fondation Bergonié, Bordeaux, France.
Abstract:
Numerous modulators of multidrug resistance present a good in vitro activity which has not always been reproduced in vivo or in clinics. One reason is the fact that the plasma concentration required might exceed the maximum tolerated dose of modulator, due to its own toxicity. In addition, it has been suggested that the different modulators thus far identified might act on different sites of P-glycoprotein and eventually on different targets. It has been shown that the combination of verapamil and quinine, and of verapamil and cyclosporine A, behave synergistically in the circumvention of multidrug resistance. There is therefore a good rationale for the evaluation of protocols combining two different modulators to cytotoxic chemotherapy.
Insights
Many drug resistance modulators show promise in lab tests but fail in clinical settings due to toxicity. Combining two modulators may overcome this, improving chemotherapy effectiveness against multidrug resistance.
Area of Science:
- Pharmacology
- Oncology
- Drug Discovery
Background:
- Multidrug resistance (MDR) significantly limits chemotherapy efficacy.
- In vitro activity of MDR modulators often doesn't translate to clinical success due to toxicity and dose limitations.
- Existing modulators may target different sites or mechanisms of P-glycoprotein, suggesting combination therapy potential.
Purpose of the Study:
- To explore the rationale for combining different multidrug resistance modulators.
- To evaluate combination protocols of modulators with cytotoxic chemotherapy.
Main Methods:
- Review of existing literature on multidrug resistance modulators.
- Analysis of synergistic effects of combined modulators (e.g., verapamil with quinine or cyclosporine A).
Main Results:
- Many modulators exhibit good in vitro activity but face in vivo toxicity issues.
- Synergistic effects observed with combinations like verapamil and quinine, and verapamil and cyclosporine A.
- Potential for overcoming resistance through combined modulator strategies.
Conclusions:
- Combining different multidrug resistance modulators is a promising strategy to enhance chemotherapy.
- Further evaluation of combination protocols is warranted to improve clinical outcomes in cancer treatment.