Drug Interaction Report
3 potential interactions and/or warnings found for the following 2 drugs:
- fexofenadine
- trospium / xanomeline
Interactions between your drugs
fexofenadine xanomeline
Applies to: fexofenadine, trospium / xanomeline
MONITOR: Xanomeline may increase the concentration of sensitive oral CYP450 3A4 substrates and/or narrow therapeutic index (NTI) oral P-glycoprotein (P-gp) substrates. In vitro data suggest that xanomeline may transiently inhibit CYP450 3A4 and P-gp locally in the intestine after dosing. Xanomeline does not appear to inhibit CYP450 3A4 and/or P-gp systemically. Clinical data evaluating this interaction are not available.
MANAGEMENT: Caution and clinical monitoring are advised if xanomeline is used in combination with an orally administered CYP450 3A4 sensitive substrate and/or NTI P-gp substrate for which a small change in substrate plasma concentration could lead to serious toxicities. The labeling of the substrate may be consulted for specific monitoring and dose adjustment recommendations should adverse reactions result from this combination.
References (1)
- (2024) "Product Information. Cobenfy (trospium-xanomeline)." Bristol-Myers Squibb
Drug and food interactions
fexofenadine food
Applies to: fexofenadine
GENERALLY AVOID: Coadministration with large amounts of certain fruit juices, including grapefruit, orange and apple, may decrease the oral bioavailability of fexofenadine. The proposed mechanism is inhibition of drug efflux via intestinal organic anion transporting polypeptides (e.g., P-glycoprotein), of which fexofenadine is a substrate. In a five-way crossover study with 10 healthy volunteers, 1/4-strength grapefruit juice, grapefruit juice, orange juice and apple juice (300 mL with drug administration and 150 mL every 1/2 hour for up to 3 hours, total volume 1.2 L) reduced the mean area under the plasma concentration-time curve (AUC) of a 120 mg dose of fexofenadine by 23%, 67%, 72% and 77%, respectively, compared to water. Mean peak plasma concentration (Cmax) was similarly affected. The clinical significance of these changes is unknown. However, results from studies using histamine-induced skin wheals and flares found that the size of wheal and flare was significantly larger when fexofenadine was administered with either grapefruit or orange juices compared to water.
MANAGEMENT: To maximize plasma levels and therapeutic effects, fexofenadine should be taken with water. In addition, patients should refrain from consuming large amounts of grapefruit, orange, or apple juice.
References (2)
- Bailey DG, Dresser GK, Munoz C, Freemar DJ, Kim RB (2001) "Reduction of fexofenadine bioavailability by fruit juices." Clin Pharmacol Ther, 69, PI-82
- Dresser GK, Bailey DG, Leake BF, et al. (2002) "Fruit juices inhibit organic anion transporting polypeptide-mediated drug uptake to decrease the oral availability of fexofenadine." Clin Pharmacol Ther, 71, p. 11-20
trospium food
Applies to: trospium / xanomeline
ADJUST DOSING INTERVAL: Food may reduce the oral absorption and bioavailability of trospium chloride. According to the product labeling, administration of trospium chloride with a high fat meal reduced the peak plasma concentration (Cmax) and area under the concentration-time curve (AUC) by 70% to 80% compared to administration while fasting.
MANAGEMENT: To ensure maximal oral absorption, trospium chloride should be administered at least 1 hour before meals or on an empty stomach. If trospium chloride is administered as a combination with xanomeline, the manufacturer recommends administering the capsules at least 1 hour before a meal or at least 2 hours after a meal. Capsules should be taken whole.
References (5)
- (2012) "Product Information. Sanctura (trospium)." Odyssey Pharmaceuticals
- (2024) "Product Information. Cobenfy (trospium-xanomeline)." Bristol-Myers Squibb
- (2019) "Product Information. Trosec (trospium)." Oryx Pharmaceuticals Inc
- (2022) "Product Information. Regurin (trospium)." Mylan Healthcare Sdn. Bhd.
- (2023) "Product Information. Trospium Chloride (trospium)." Padagis
Therapeutic duplication warnings
No duplication 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.
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. |
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Further information
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