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Phentermine and topiramate and Zyrtec

Determining the interaction of Phentermine and topiramate and Zyrtec and the possibility of their joint administration.

Check result:
Phentermine and topiramate <> Zyrtec
Relevance: 06.08.2023 Reviewer: Shkutko P.M., M.D., in

In the database of official manuals used in the service creation an interaction registered by statistical results of studies was found, which can either lead to negative consequences for the patient health or strengthen a mutual positive effect. A doctor should be consulted to address the issue of joint drug administration.

Consumer:

Topiramate may increase the blood levels and effects of phentermine. You may need a dose adjustment or more frequent monitoring by your doctor to safely use both medications. Contact your doctor if you experience increased side effects such as dizziness, restlessness, insomnia, tremor, headache, mood changes, palpitation, rapid heart beat, or blood pressure elevation. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

Professional:

MONITOR: Coadministration with topiramate may increase the plasma concentrations of phentermine. The exact mechanism of interaction has not been established. When a single 15 mg dose of phentermine was administered with a 92 mg dose of topiramate, phentermine peak plasma concentration (Cmax) and systemic exposure (AUC) increased by 13% and 42%, respectively, compared to phentermine administered alone. No significant changes were observed in the pharmacokinetics of topiramate.

MANAGEMENT: Caution is advised when phentermine is used in combination with topiramate. Patients should be monitored for potentially increased adverse effects of phentermine such as dizziness, restlessness, insomnia, tremor, headache, euphoria, dysphoria, palpitation, tachycardia, and blood pressure elevation.

References
  • "Product Information. Ionamin (phentermine)." Rhone-Poulenc Rorer, Collegeville, PA.
Phentermine and topiramate

Generic Name: phentermine / topiramate

Brand name: Qsymia

Synonyms: Phentermine and Topiramate

Zyrtec

Generic Name: cetirizine

Brand name: All Day Allergy, All Day Allergy Children's, GoodSense All Day Allergy, Indoor/Outdoor Allergy Relief, Zyrtec, Zyrtec

Synonyms: n.a.

In the course of checking the drug compatibility and interactions, data from the following reference sources was used: Drugs.com, Rxlist.com, Webmd.com, Medscape.com.

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