Clemastine
Written By Dr. Subita Alagh
Reviewed By Dr. Rajeev SharmaLast updated 25 Nov 2025 | 09:34 AM (UTC)
Clemastine Uses
Clemastine is used in the treatment of allergic conditions.
How Clemastine works
Clemastine is an antihistaminic medication. It blocks the action of certain chemical messengers that are responsible for inflammation, congestion, itching, and other allergic reactions.
Common side effects of Clemastine
Fatigue, Sedation
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Expert advice for Clemastine
- Avoid driving or operating dangerous machinery as it may decrease alertness.
- Avoid consuming alcohol when taking the Clemastine, as it may cause excessive sleepiness or drowsiness.
- Avoid driving or operating dangerous machinery as it may decrease alertness.
- Avoid consuming alcohol when taking the Clemastine, as it may cause excessive sleepiness or drowsiness.
Frequently asked questions for Clemastine
Clemastine is an anti-allergic that works by blocking the action of a chemical named histamine, which causes allergic symptoms.
Yes, this medicine has sedative properties and can make you feel sleepy. So, it is advisable to avoid driving or indulging in any sort of activity.
No, it is not advisable to drink alcohol while taking this medicine since it can raise your risk of side effects, especially sleepiness. Talk to your doctor in case of any doubts.
You may start to feel the effects of this medicine in 2-3 hours. The full effects of this medication are usually felt after 5 to 7 hours of taking the dose.
If you accidentally take Clemastine in excess, you may develop symptoms like rapid heartbeat, dilated pupils (larger than normal size) or flushing, upset stomach, and dry mouth. Contact your doctor or hospital casualty department immediately.
If you happen to miss a dose, take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up for the missed dose. Discuss this with your doctor. In order to avoid missing a dose, use a calendar, pillbox, alarm clock, or cell phone alert to help you remember to take your medication. You may also ask a family member a friend to remind you or check in with you to be sure you are taking your medication.