Chlorcyclizine
Chlorcyclizine is a first-generation antihistamine medication used to treat various allergic conditions including hay fever, allergic rhinitis, and skin reactions such as hives. It works by blocking histamine H1 receptors in the body, which helps reduce common allergy symptoms like sneezing, itching, watery eyes, and runny nose. This medication has been available for many years and is used in patients who need relief from acute or chronic allergic symptoms.
Chlorcyclizine is an antihistamine used to treat allergies by blocking histamine receptors and relieving symptoms like sneezing, itching, and runny nose.
Key facts at a glance
- ATC
- R06AE04
- RxNorm
- 20823
- Generic
- Chlorcyclizine
- Class
- atc-r06
- Brands
- Dallergy Reformulated Nov 2011, Stahist AD, Ahist Antihistamine
- Availability
- otc
- Pregnancy
- C
- Lactation
- caution
- Half-life (h)
- 12
- Onset (min)
- 30
- Duration (h)
- 6
- Routes
- oral
- Forms
- tablet, capsule
- Regions
- United States
- Monitoring
- sedation, anticholinergic effects
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.
Chlorcyclizine is used to treat allergic rhinitis (hay fever), seasonal allergies, chronic urticaria (hives), allergic skin reactions, and pruritus (itching). It may also be used for allergic conjunctivitis and other histamine-mediated allergic conditions.
Chlorcyclizine works by blocking H1 histamine receptors in the body. Histamine is a substance released during allergic reactions that causes symptoms like itching, sneezing, and nasal discharge. By preventing histamine from binding to these receptors, chlorcyclizine reduces or eliminates allergic symptoms.
As a first-generation antihistamine, chlorcyclizine may cause drowsiness, dry mouth, blurred vision, and dizziness. Patients should avoid alcohol and use caution when driving or operating machinery. It may interact with other sedating medications or anticholinergic drugs. Consult a healthcare provider before use if pregnant, breastfeeding, or taking other medications.
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