Terfenadine is an antihistamine that is used to treat allergies.

It works by blocking the action of histamine, a substance that causes allergic symptoms.

Terfenadine Side effects can include drowsiness, dizziness, nausea and abdominal pain.

Due to these side effects terfenadine should not be taken before driving or operating machinery.

If you are pregnant or breastfeeding then consult your doctor before taking terfenadine as it may harm your baby.

Likewise if you have liver disease or kidney disease avoid terfenadine as it will worsen this condition.

Taking two doses close together could lead to life-threatening heart rhythm problems.

Make sure to take at least four hours between doses of terfenadine.

Terfenadine can interact with other drugs, including over-the-counter medications, vitamins, and supplements.

These interactions can increase your risk of side effects or make the medication less effective.

If you are taking any medications, tell your doctor before starting terfenadine.