Clemastine Fumarate
Clemastine fumarate is an antihistamine medication used to treat a variety of allergic conditions. It works by blocking the action of histamine, a substance in the body that causes allergic symptoms. This medication is commonly prescribed for seasonal allergies, allergic rhinitis, and associated symptoms like sneezing, itching, and runny nose.
Antihistamine medication for treating allergies and their associated symptoms.
Key facts at a glance
- RxNorm
- 142430
- Generic
- Clemastine Fumarate
- Class
- pin-variant
- Brands
- Dayhist-1, Wal-Hist 12 HR Relief, Clemasz, Clemsza, Tavist
- Availability
- rx
- Lactation
- unknown
- Routes
- —
- Forms
- —
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Treatment of seasonal allergic rhinitis (hay fever), perennial allergic rhinitis, and other allergic conditions including sneezing, rhinorrhea, itching, and watery eyes. May also be used for allergic skin reactions and pruritus (itching).
Clemastine fumarate is a selective H1 histamine receptor antagonist. It blocks the binding of histamine to these receptors, thereby reducing or preventing allergic symptoms such as sneezing, itching, and nasal discharge.
May cause drowsiness; avoid operating machinery or driving until aware of effects. Use with caution in patients with glaucoma, urinary retention, or thyroid disorders. May interact with other sedating medications or alcohol. Not recommended for use in elderly patients due to increased sensitivity to anticholinergic effects. Consult healthcare provider before use if pregnant or breastfeeding.
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 27, 2026. · Read our editorial policy