Drug Interactions between dofetilide and rifapentine
This report displays the potential drug interactions for the following 2 drugs:
- dofetilide
- rifapentine
Interactions between your drugs
rifapentine dofetilide
Applies to: rifapentine and dofetilide
Dofetilide is metabolized to a small extent by CYP450 3A4 microsomal enzymes in the liver. The clinician should be aware of the potential for an interaction when dofetilide is used in combination with another medication that induces CYP450 3A4. When concomitant therapy is required, the manufacturer recommends monitoring the patient for alterations in therapeutic effect. Dosage modifications may be necessary.
References (1)
- (2001) "Product Information. Tikosyn (dofetilide)." Pfizer U.S. Pharmaceuticals
Drug and food interactions
rifapentine food
Applies to: rifapentine
ADJUST DOSING INTERVAL: Administration with food may increase the oral bioavailability of rifapentine and reduce the incidence of gastrointestinal adverse events. Administration with a high fat meal typically increases rifapentine's maximum concentration (Cmax) and systemic exposure (AUC) by approximately 40% to 50% over that observed when rifapentine is administered under fasting conditions. Rifapentine is often prescribed in combination with isoniazid. When single doses of rifapentine (900 mg) and isoniazid (900 mg) were administered with a low fat, high carbohydrate breakfast, the Cmax and AUC of rifapentine increased by 47% and 51%, respectively. On the other hand, isoniazid's Cmax and AUC decreased by 46% and 23%, respectively.
MANAGEMENT: Products containing oral rifapentine as the sole ingredient recommend administration with a meal to increase bioavailability and reduce the occurrence of gastrointestinal upset, nausea, and/or vomiting. Consultation of product labeling for combination products and/or relevant guidelines may be helpful if rifapentine is combined with a medication that is typically taken on an empty stomach.
References (2)
- (2021) "Product Information. Isoniazid/Rifapentine 300 mg/300 mg (Macleods) (isoniazid-rifapentine)." Imported (India), 2
- (2021) "Product Information. Priftin (rifapentine)." sanofi-aventis
dofetilide food
Applies to: dofetilide
In vitro data suggest that grapefruit juice may inhibit the CYP450 3A4 first-pass metabolism of dofetilide. Decreased first-pass metabolism may increase dofetilide concentrations and increase the risk of QT interval prolongation and arrhythmias. The clinical significance is unknown, since dofetilide has a high oral bioavailability and a low affinity for CYP450 3A4. The manufacturer recommends caution.
References (1)
- (2001) "Product Information. Tikosyn (dofetilide)." Pfizer U.S. Pharmaceuticals
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
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
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