What is Clemastine: Uses, Warnings & Interactions

Updated May 14, 2025  •  Published Dec 30, 2020

Clemastine overview

BRAND NAMES:

  • Tavist Allergy, TopCare Dayhist Allergy, TopCare Dayhist Allergy, TopCare Dayhist Allergy, TopCare Dayhist Allergy

Generic Names:

  • Clemastine Fumarate

Uses:

  • Treats allergy symptoms (hay fever).

Therapeutic Classes:

  • Respiratory Agent

Forms:

  • Liquid, Tablet

How it’s taken:

  • By mouth

What is Clemastine used for?

What form(s) does Clemastine come in

  • Liquid

  • Tablet

What are common Clemastine doses?

  • Tablet 2.68MG

Common Clemastine prescriptions

  • Clemastine Fumarate
    100 tablets bottle

  • Clemastine Fumarate
    120ml of 0.67mg/5ml bottle

  • Clemastine Fumarate
    2.68mg tablet

How to take Clemastine

  • Keep this medicine at room temperature, away from heat, direct light, and moisture. Do not freeze the oral liquid.

  • Missed dose: Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose.

  • You may take this medicine with food to prevent stomach upset.

  • Missed dose: Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose.

  • Keep this medicine at room temperature, away from heat, direct light, and moisture. Do not freeze the oral liquid.

  • You may take this medicine with food to prevent stomach upset.

What to do if you miss a dose of Clemastine

Clemastine contraindications

  • This medicine is not right for everyone. Do not use it if you had an allergic reaction to clemastine or any other antihistamine medicines. Do not use it if you are breastfeeding, you have a lung disorder such as asthma, or you are using a monoamine oxidase inhibitor (MAOI) such as isocarboxazid, phenelzine, selegiline, or tranylcypromine.

Clemastine warnings

  • This medicine may make you drowsy. Be careful when you drive or operate dangerous machinery.

  • Keep all medicine out of the reach of children. Never share your medicine with anyone.

  • Tell your doctor if you have glaucoma, an ulcer, or problems with your bladder or prostate.

  • This medicine should not be given to children under 12 years of age unless ordered by a doctor.

  • Side effects of this medicine may be more likely in children and older adults. Clemastine syrup contains alcohol.

  • Tell your doctor if you are pregnant or breastfeeding.

Clemastine interactions

  • Keep all medicine out of the reach of children. Never share your medicine with anyone.

  • This medicine may make you drowsy. Be careful when you drive or operate dangerous machinery.

  • Side effects of this medicine may be more likely in children and older adults. Clemastine syrup contains alcohol.

  • Some medicines and foods can affect how clemastine works. Tell your doctor if you are using any of the following: AntidepressantsNarcotic pain killersOther antihistaminesSleeping pillsTranquilizers

  • Do not drink alcohol while you are taking this medicine.

  • This medicine should not be given to children under 12 years of age unless ordered by a doctor.

Clemastine side effects

Serious Side Effects

  • Severe drowsiness

  • Fainting

  • Facial flushing

  • Trouble breathing

Less Serious Side Effects

  • Nausea, vomiting, diarrhea, constipation

  • Clumsiness, mild drowsiness, or dizziness

  • Urinating often, trouble urinating

  • Dry mouth or throat, or thickening of mucus