Drug Interactions between mercaptopurine and Tequin
This report displays the potential drug interactions for the following 2 drugs:
- mercaptopurine
- Tequin (gatifloxacin)
Interactions between your drugs
mercaptopurine gatifloxacin
Applies to: mercaptopurine and Tequin (gatifloxacin)
Limited data suggest that chemotherapy with antineoplastic agents may reduce the plasma concentrations of oral quinolone antibiotics. The proposed mechanism is decreased quinolone absorption secondary to alteration of intestinal mucosa by cancer chemotherapy. In six patients with newly diagnosed hematologic malignancy, treatment with various antineoplastic agents (cyclophosphamide, cytarabine, daunorubicin, doxorubicin, mitoxantrone, prednisolone, vincristine) decreased the mean peak serum concentration (Cmax) and area under the concentration-time curve (AUC 0 to 4 hours) of ciprofloxacin by approximately 46% each. Data are not available for other quinolone antibiotics.
References
- Johnson EJ, MacGowan AP, Potter MN, et al. (1990) "Reduced absorption of oral ciprofloxacin after chemotherapy for haematological malignancy." J Antimicrob Chemother, 25, p. 837-42
Drug and food interactions
mercaptopurine food
Applies to: mercaptopurine
ADJUST DOSING INTERVAL: Limited data suggest that food may decrease the oral bioavailability of 6-mercaptopurine (6-MP). In one study, the pharmacokinetics of 6-MP were studied on two separate occasions in seven patients. A single dose of 6-MP was administered after an overnight fast on one occasion and 15 minutes after a standard breakfast on the other. The authors reported that peak plasma levels of 6-MP were lower and took longer to reach following administration in the fed state. In addition, plasma levels were undetectable (less than 20 ng/mL) in two patients.
MANAGEMENT: Until more information is available regarding the effect of food on 6-MP absorption, it may be advisable to take 6-MP on an empty stomach 1 hour before or 2 hours after a meal.
References
- Schmidt LE, Dalhoff K (2002) "Food-drug interactions." Drugs, 62, p. 1481-502
gatifloxacin food
Applies to: Tequin (gatifloxacin)
Concurrent ingestion of calcium-fortified foods (i.e., cereal, orange juice) may alter the bioavailability of gatifloxacin. The mechanism is chelation of calcium and the quinolone, resulting in decreased bioavailability. In the case of orange juice, inhibition of intestinal transport mechanisms (P-glycoprotein or organic anion-transporting polypeptides) by flavones may also be involved. Data have been conflicting: One study has reported no effect with milk coadministration. Another study reported a modest decrease in gatifloxacin bioavailability (13.5% decrease in Cmax,12% decrease in AUC, 15% increase in total clearance) when taken with 12 ounces of calcium-fortified orange juice instead of water, which could be clinically significant if the infecting organisms have borderline susceptibilities. The manufacturer states that gatifloxacin may be taken without regard to food, milk, or calcium. Clinicians should be aware of the possibility of an interaction if subtherapeutic effects are observed.
References
- (2001) "Product Information. Tequin (gatifloxacin)." Bristol-Myers Squibb
- Wallace AW, Victory JM, Amsden GW (2003) "Lack of bioequivalence of gatifloxacin when coadministered with calcium-fortified orange juice in healthy volunteers." J Clin Pharmacol, 43, p. 92-6
Therapeutic duplication warnings
No warnings were found for your selected drugs.
Therapeutic duplication warnings are only returned when drugs within the same group exceed the recommended therapeutic duplication maximum.
See also
Drug Interaction Classification
Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit. | |
Moderately clinically significant. Usually avoid combinations; use it only under special circumstances. | |
Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan. | |
No interaction information available. |
Further information
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