(fesoterodine fumarate)

Prescribing Information
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7 DRUG INTERACTIONS

7 DRUG INTERACTIONS

7.1 Antimuscarinic Drugs

Coadministration of Toviaz with other antimuscarinic agents that produce dry mouth, constipation, urinary retention, and other anticholinergic pharmacological effects may increase the frequency and/or severity of such effects. Anticholinergic agents may potentially alter the absorption of some concomitantly administered drugs due to anticholinergic effects on gastrointestinal motility.

7.2 CYP3A4 Inhibitors

Doses of Toviaz greater than 4 mg are not recommended in adult patients taking strong CYP3A4 inhibitors, such as ketoconazole, itraconazole, and clarithromycin [see Dosage and Administration (2.5)]. The Toviaz dose in pediatric patients taking strong CYP3A4 inhibitors is recommended to be reduced to 4 mg once daily in patients >35 kg and is not recommended in patients weighing greater than 25 kg and up to 35 kg [see Dosage and Administration (2.5)].

In a study in adults, coadministration of the strong CYP3A4 inhibitor ketoconazole with fesoterodine led to approximately a doubling of the maximum concentration (Cmax) and area under the concentration versus time curve (AUC) of 5-hydroxymethyl tolterodine (5-HMT), the active metabolite of fesoterodine. Compared with CYP2D6 extensive metabolizers not taking ketoconazole, further increases in the exposure to 5-HMT were observed in subjects who were CYP2D6 poor metabolizers taking ketoconazole [see Clinical Pharmacology (12.3)].

There is no clinically relevant effect of moderate CYP3A4 inhibitors on the pharmacokinetics of fesoterodine. Following blockade of CYP3A4 by coadministration of the moderate CYP3A4 inhibitor fluconazole 200 mg twice a day for 2 days, the average (90% confidence interval) increase in Cmax and AUC of the active metabolite of fesoterodine was approximately 19% (11%–28%) and 27% (18%–36%) respectively. No dosing adjustments are recommended in the presence of moderate CYP3A4 inhibitors (e.g., erythromycin, fluconazole, diltiazem, verapamil and grapefruit juice).

The effect of weak CYP3A4 inhibitors (e.g. cimetidine) was not examined; it is not expected to be in excess of the effect of moderate inhibitors [see Clinical Pharmacology (12.3)].

7.3 CYP3A4 Inducers

No dosing adjustments are recommended in the presence of CYP3A4 inducers, such as rifampin and carbamazepine. Following induction of CYP3A4 by coadministration of rifampin 600 mg once a day, Cmax and AUC of the active metabolite of fesoterodine decreased by approximately 70% and 75%, respectively, after oral administration of Toviaz 8 mg. The terminal half-life of the active metabolite was not changed.

7.4 CYP2D6 Inhibitors

The interaction with CYP2D6 inhibitors was not tested clinically. In poor metabolizers for CYP2D6, representing a maximum CYP2D6 inhibition, Cmax and AUC of the active metabolite are increased 1.7- and 2-fold, respectively.

No dosing adjustments are recommended in the presence of CYP2D6 inhibitors.

7.5 Drugs Metabolized by Cytochrome P450

In vitro data indicate that at therapeutic concentrations, the active metabolite of fesoterodine does not have the potential to inhibit or induce Cytochrome P450 enzyme systems [see Clinical Pharmacology (12.3)].

7.6 Oral Contraceptives

In the presence of fesoterodine, there are no clinically significant changes in the plasma concentrations of combined oral contraceptives containing ethinyl estradiol and levonorgestrel [see Clinical Pharmacology (12.3)].

7.7 Warfarin

A clinical study has shown that fesoterodine 8 mg once daily has no significant effect on the pharmacokinetics or the anticoagulant activity (PT/INR) of warfarin 25 mg. Standard therapeutic monitoring for warfarin should be continued [see Clinical Pharmacology (12.3)].

7.8 Drug-Laboratory Test Interactions

Interactions between Toviaz and laboratory tests have not been studied.

Medication Guide

MEDICATION GUIDE

Patient Information
TOVIAZ® (TOH-vee-as)
(fesoterodine fumarate)
extended-release tablets, for oral use

Read the Patient Information that comes with TOVIAZ before you start taking it and each time you get a refill. There may be new information. This leaflet does not take the place of talking with your healthcare provider about your medical condition or your treatment.

What is TOVIAZ?
TOVIAZ is a prescription medicine used:

•
in adults to treat symptoms of a condition called overactive bladder (OAB), including urge urinary incontinence (leaking or wetting accidents due to a strong need to urinate), urinary urgency (having a strong need to urinate right away), or urinary frequency (having to urinate too often).
•
in children 6 years of age and older with a body weight greater than 55 pounds (25 kg) to treat neurogenic detrusor overactivity (NDO). TOVIAZ is used to increase the amount of urine your bladder can hold and reduce urine leakage.

It is not known if TOVIAZ is safe and effective in children younger than 6 years of age or with a body weight 55 pounds (25-kg) or less.

Who should not take TOVIAZ?
Do not take TOVIAZ if you:

•
are allergic to TOVIAZ or any of its ingredients. See the end of this leaflet for a complete list of ingredients.
•
are allergic to tolterodine tartrate tablets or tolterodine tartrate extended-release capsules.
•
are not able to empty your bladder (urinary retention).
•
have delayed or slow emptying of your stomach (gastric retention).
•
have an eye problem called uncontrolled narrow-angle glaucoma.

Before you take TOVIAZ, tell your healthcare provider about all your medical conditions, including if you:

•
have problems emptying your bladder or you have a weak urine stream.
•
have any stomach or intestinal problems, or problems with constipation.
•
are receiving treatment for an eye problem called narrow-angle glaucoma.
•
have a condition called Myasthenia Gravis.
•
have kidney problems.
•
have liver problems.
•
are pregnant or plan to become pregnant. It is not known if TOVIAZ will harm your unborn baby. Talk to your healthcare provider if you are pregnant or plan to become pregnant.
•
are breastfeeding or plan to breastfeed. It is not known if TOVIAZ passes into your breast milk. You should talk to your healthcare provider about the best way to feed your baby while taking TOVIAZ.

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal products. TOVIAZ may affect the way other medicines work, and other medicines may affect how TOVIAZ works. Especially tell your healthcare provider if you are taking antimuscarinic, antibiotics, or antifungal medicines.

Know all the medicines you take. Keep a list of them with you to show your healthcare provider and pharmacist each time you get a new medicine.

How should I take TOVIAZ?

•
Take TOVIAZ exactly as your healthcare provider tells you to take it.
•
Your healthcare provider may lower your dose of TOVIAZ if you are an adult with severe kidney problems.
•
Your healthcare provider may lower or stop your dose of TOVIAZ if you are a child 6 years of age and older with a body weight greater than 77 pounds (35 kg) and have severe kidney problems or are taking certain medicines.
•
Take TOVIAZ with liquid and swallow the tablet whole. Do not chew, divide, or crush the tablet.
•
Take TOVIAZ with or without food.
•
If you miss a dose of TOVIAZ, begin taking TOVIAZ again the next day. Do not take 2 doses of TOVIAZ in the same day.
•
If you take too much TOVIAZ, call your healthcare provider or go to an emergency department right away.

What should I avoid while taking TOVIAZ?

•
TOVIAZ can cause blurred vision, dizziness, and drowsiness. Do not drive, operate machinery, or do other dangerous activities until you know how TOVIAZ affects you.
•
Use caution in hot environments. Decreased sweating and severe heat illness can happen when medicines such as TOVIAZ are used in a hot environment.
•
Drinking alcohol while taking medicines such as TOVIAZ may cause increased drowsiness.

What are the possible side effects of TOVIAZ?
TOVIAZ may cause serious side effects, including:

•
serious allergic reactions. Symptoms of a serious allergic reaction may include swelling of the face, lips, throat, or tongue. If you have any of these symptoms, you should stop taking TOVIAZ and get emergency medical help right away.
•
inability to empty bladder (urinary retention). TOVIAZ may increase your chances of not being able to empty your bladder if you have bladder outlet obstruction. Tell your healthcare provider right away if you are unable to empty your bladder.
•
central nervous system (CNS) effects. Talk to your healthcare provider right away if you get any of these side effects: headache, dizziness, and drowsiness.
•
worsening of Myasthenia Gravis symptoms.

The most common side effects of TOVIAZ in adults include:

•
dry mouth
•
constipation

The most common side effects of TOVIAZ in children 6 years of age and older include:

•
diarrhea
•
urinary tract infection
•
dry mouth
•
constipation
•
stomach pain
•
nausea
•
weight gain
•
headache

Talk to your healthcare provider about any side effect that bothers you or that does not go away. These are not all the possible side effects of TOVIAZ. Call your healthcare provider for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

How should I store TOVIAZ?

•
Store TOVIAZ at room temperature between 68° to 77°F (20° to 25°C).
•
Protect the medicine from moisture by keeping the bottle closed tightly.
•
Keep TOVIAZ and all medicines out of the reach of children.

General information about the safe and effective use of TOVIAZ.
Medicines are sometimes prescribed for purposes other than those listed in a Patient Information leaflet. Do not use TOVIAZ for a condition for which it was not prescribed. Do not give TOVIAZ to other people, even if they have the same symptoms you have. It may harm them. You can ask your pharmacist or healthcare provider for information about TOVIAZ that is written for health professionals.

What are the ingredients in TOVIAZ?
Active ingredient: fesoterodine fumarate.
Inactive ingredients: glyceryl behenate, hypromellose, indigo carmine aluminum lake, lactose monohydrate, soya lecithin, microcrystalline cellulose, polyethylene glycol, polyvinyl alcohol, talc, titanium dioxide, and xylitol.

This product's labeling may have been updated. For the most recent prescribing information, please visit www.pfizer.com.

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LAB-0382-14.0
For more information, go to www.TOVIAZ.com or call 1-877-9-TOVIAZ (1-877)-986-8429.

This Patient Information has been approved by the U.S. Food and Drug Administration.

Revised: 2/2024

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