Clemastine: What is it? Uses, Instructions for Use, Side Effects and Precautions

It is an antihistamine used to relieve the symptoms of allergy, hay fever and the common cold.

Uses of Clemastine

These symptoms include a rash, watery eyes, itchy eyes / nose / throat / skin, cough, runny nose and sneezing.

This medication works by blocking a certain natural substance (histamine) that your body makes during an allergic reaction.

By blocking another natural substance produced by the body ( acetylcholine ), it helps dry some body fluids to relieve symptoms such as watery eyes and runny nose.

It has not been demonstrated that products with and without cough are safe or effective in children under 6 years of age. Therefore, do not use this product to treat cold symptoms in children under 6 unless specifically directed by the doctor.

Some products (such as long-acting pills / capsules) are not recommended for children under 12 years of age. Consult your doctor or pharmacist for more information about the safe use of your product.

These products do not cure or shorten the duration of the common cold and can cause serious side effects.

To reduce the risk of serious side effects, carefully follow all dosage instructions. Do not use this product to make the child sleepy.

Do not give other cough and cold medicines that may contain the same ingredients or similar ingredients (see also the Interactions with other medicines section).

Ask your doctor or pharmacist about other ways to relieve cough and cold symptoms (such as drinking enough fluids, using a humidifier, or saline drops / sprays).

How to use

If you are taking an over-the-counter medication, read all instructions on the product package before taking this medication. If you have any questions, ask your pharmacist.

If your doctor has prescribed this medication, take it as directed. Take the tablet or liquid by mouth with or without food. Follow the instructions for dosing on the label, or take as directed by your doctor.

This medicine can be taken with food or milk if stomach upset occurs. If you are using the liquid, use a medication measuring device to carefully measure the prescribed dose.

Do not use a domestic spoon. Your dosage will depend on your age, medical condition and response to therapy.

Do not increase your dose or take this medication more often than recommended by your doctor or the package instructions without your doctor’s approval.

Take this medication regularly to get the most benefit from it. To remember, take it at the same time every day. If your condition persists or worsens, or if you think you may have a serious medical problem, seek immediate medical attention.

Side Effects of Clemastine

Drowsiness, dizziness, headache, constipation, upset stomach, blurred vision, difficulty walking / clumsiness, or dry mouth / nose / throat may occur.

To relieve dry mouth, suck on candy (without sugar) or ice chips, chew gum (no sugar), drink water or use a saliva substitute.

Clemastine can dry out and thicken the mucus in your lungs, which makes it harder to breathe and clean your lungs. To help prevent this effect, drink plenty of fluids unless your doctor tells you otherwise.

If your doctor has prescribed this medication, remember that he or she has determined that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor immediately if you have any of these unlikely but serious side effects:

Mental / mood changes (for example, hallucinations, irritability, nervousness, confusion), ringing in the ears, difficulty urinating.

Tell your doctor immediately if you have any of these rare but very serious side effects: easy bruising / bleeding, fast / irregular heartbeat, seizures.

It is unlikely that a very serious allergic reaction to this drug will occur.

However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including: rash, itching / swelling (especially of the face / tongue / throat), severe dizziness, trouble breathing.


Before taking clemastine, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems.

Consult your pharmacist for more information.

Before using this medication, tell your doctor or pharmacist your medical history, especially about:

Respiratory problems (for example, asthma , emphysema ), certain eye problems ( glaucoma ), heart problems, high blood pressure , liver disease, seizures, stomach problems.

Also ulcers, obstruction, overactive thyroid ( hyperthyroidism ), problems of urination (for example, difficulty urinating due to enlarged prostate, urinary retention).

This medicine may cause dizziness, drowsiness or blurred vision. Do not drive, use machinery or perform activities that require alertness or a clear vision until you are sure you can perform those activities safely.

Limit the use of alcohol and certain other medications that cause drowsiness. (Also see Interactions with other medications).

To minimize dizziness and lightheadedness, get up slowly when you get up while sitting or lying down. The liquid preparations of this product may contain sugar and / or alcohol.

Caution is advised if you have diabetes, alcohol dependence or liver disease. Ask your doctor or pharmacist about the safe use of this product.

Older adults may be more sensitive to the side effects of this medication, especially drowsiness, constipation, trouble urinating, or confusion.

Drowsiness and confusion can increase the risk of falls. Children may be more sensitive to the effects of antihistamines . In young children, this medication may cause agitation / excitement instead of drowsiness.

During pregnancy, this medication should be used only when clearly necessary. Talk to your doctor about the risks and benefits. This medicine passes into breast milk and may have undesirable effects on the infant. Consult your doctor before breast-feeding.