Drug Interaction Checker

Find out if your medicines are safe to take together.

1 Add each medicine you take: the brand on the box or the medicine inside it.
2 We check every pair, including each ingredient of combination medicines.
3 See what could happen and what to do, in plain language.

Your medicines

Take these together with care

We found interactions that usually need care rather than stopping a medicine. Your doctor may adjust a dose or check on you more often.

1 Moderate 1 pair checked

1 interaction

Fesoterodine Fumarate Rifampicin

Moderate

Rifampicin (rifampin) and carbamazepine are CYP3A4 inducers, meaning they speed up the enzyme that breaks down fesoterodine's active form. When rifampin 600 mg was taken once a day with Toviaz (fesoterodine) 8 mg, the peak level (Cmax) of the active metabolite fell by about 70%. The total amount of it in the blood over time (AUC) fell by about 75%. Even so, the leaflet says no dose change is recommended when a CYP3A4 inducer like rifampin is used.

What should I do?

These medicines are often taken together with some care. Your doctor may change a dose, space them apart or check on you more often. Make sure your doctor and pharmacist know you take both.

Feeling unwell after taking your medicines? For an emergency call 999. For free advice from a doctor, call the 16263 health line (Shasthya Batayon), any time.

What do Major, Moderate and Minor mean?

Major

The combination can cause serious harm or stop a medicine from working. Usually avoided, or only used with close medical supervision.

Moderate

The combination may need care: a different dose, taking them at different times, or extra check-ups.

Minor

Little or no effect is expected. Usually nothing needs to change.

Duplicate

Two of your medicines contain the same ingredient, which can add up to a double dose.

Important: This checker lists interactions found in medicine leaflets and may not be complete. It does not know your dose, your health conditions, or food and supplement interactions. Never start, stop or change a medicine because of this tool alone: ask a registered doctor or pharmacist.