ISSN:
1569-8041
Keywords:
chemotherapy
;
drug interaction
;
in vitroassay
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract Background: Chemotherapy using multi-drug regimens is consideredmore active than single-agent therapy. This may be due to synergisticinteractions or, simply, a higher probability of administering an activeagent. We investigated in vitrothe type of drug interactions in arecognized regimen in relationship to tumour type and drug sensitivity. Patients and methods: The possibility of synergistic and additiveinteractions between individual cytotoxic drugs was investigated for thecomponent drugs of the established FEC regimen, i.e., 5-fluorouracil,epirubicin and cyclophosphamide, in 243 patient tumour samples representingvarious drug sensitivity using the non-clonogenic fluorometric microculturecytotoxicity assay. Results: Using a cell survival of ≤50% as a limit fordrug activity and sample sensitivity, the overall response rates to the mostactive single drug (Dmax) and the combination were 56% and64%, respectively, with a distribution among diagnoses similar to thatin the clinic. For 86% of the samples there was concordance withrespect to judgement of activity using either Dmax or thecombination. For samples being sensitive to at least one single drug,95% were also sensitive to the combination whereas for samples withinsignificant Dmax effect, only 2% were sensitive to thecombination. In samples with modest Dmax effects, i.e., cellsurvival in the range 〉50%–≤80%, 45%responded to the combination. The effect of the combination was generally wellpredicted from the Dmax effect. Conclusions:The superior antitumour effect of drug combinationscompared with single drugs may be due to the higher chance of selecting anactive agent. However, for intermediately sensitive tumours, additionalinteraction effects of a combination may be of clinical significance.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1008332816407
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