Drug Interactions between Intuniv and ritlecitinib
This report displays the potential drug interactions for the following 2 drugs:
- Intuniv (guanfacine)
- ritlecitinib
Interactions between your drugs
guanFACINE ritlecitinib
Applies to: Intuniv (guanfacine) and ritlecitinib
MONITOR: Coadministration with ritlecitinib may increase the plasma concentrations and effects of drugs that are primarily metabolized by the CYP450 3A4 isoenzyme. The mechanism is reduced clearance due to inhibition of CYP450 3A4 by ritlecitinib. When ritlecitinib (200 mg once daily for 11 days) was administered in combination with the sensitive CYP450 3A4 substrate midazolam, the mean peak plasma concentration (Cmax) and systemic exposure (AUC) of midazolam increased by 1.81- and 2.69-fold, compared to administration of midazolam alone. The interaction may be significant for sensitive CYP450 3A4 substrates or those that demonstrate a narrow therapeutic index.
MANAGEMENT: Caution is advised with the concomitant use of ritlecitinib with CYP450 3A4 substrates, particularly sensitive substrates or those that demonstrate a narrow therapeutic index (e.g., cisapride, ergot alkaloids, colchicine, fentanyl, macrolide immunosuppressants, midazolam, pimozide, triazolam, vinca alkaloids). If concomitant use is required, clinical and laboratory monitoring may be appropriate whenever ritlecitinib is added to or withdrawn from therapy. The prescribing information for concomitant medications should be consulted to assess the benefits versus risks of coadministration and for any dosage adjustments that may be required.
References
- (2023) "Product Information. Litfulo (ritlecitinib)." Pfizer U.S. Pharmaceuticals Group
Drug and food interactions
guanFACINE food
Applies to: Intuniv (guanfacine)
GENERALLY AVOID: Grapefruit juice may increase the plasma concentrations of guanfacine. The risk of adverse reactions such as hypotension, bradycardia, and sedation may increase. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruit. Ketoconazole, a potent CYP450 3A4 inhibitor, has been reported to increase guanfacine peak plasma concentration (Cmax) and systemic exposure (AUC) by approximately 2- and 3-fold, respectively. A computer simulation suggests that fluconazole, a moderate CYP450 3A4 inhibitor, would increase guanfacine Cmax and AUC by about 1.5- and 2-fold, respectively. In general, the effect of grapefruit juice is concentration-, dose- and preparation-dependent, and can vary widely among brands. Certain preparations of grapefruit juice (e.g., high dose, double strength) have sometimes demonstrated potent inhibition of CYP450 3A4, while other preparations (e.g., low dose, single strength) have typically demonstrated moderate inhibition.
GENERALLY AVOID: Alcohol may enhance the sedative and hypotensive effects of guanfacine.
GENERALLY AVOID: Administration of extended-release guanfacine with a high-fat meal may increase the bioavailability of guanfacine. When a single 4 mg dose of extended-release guanfacine was administered to adult volunteers with a high-fat breakfast, mean guanfacine peak plasma concentration (Cmax) and systemic exposure (AUC) increased by approximately 75% and 40%, respectively, compared to dosing in a fasted state.
MANAGEMENT: Patients treated with guanfacine should avoid consumption of grapefruit and grapefruit juice. In addition, it is preferable to avoid or limit the use of alcohol during treatment. Patients should be advised against driving or operating hazardous machinery until they know how the medication affects them. The extended-release formulation of guanfacine should not be taken together with a high-fat meal.
References
- (2001) "Product Information. Tenex (guanfacine)." Wyeth-Ayerst Laboratories
- Cerner Multum, Inc. "UK Summary of Product Characteristics."
- (2009) "Product Information. Intuniv (guanfacine)." Shire US Inc
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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