MedicineNet.com

SIDE EFFECTS: Drowsiness, dizziness, headache, constipation, stomach upset, blurred vision, trouble walking/clumsiness, or dry mouth/nose/throat may occur. These effects may decrease as your body adjusts to the medication. If any of these effects persist or worsen, contact your doctor or pharmacist promptly.To relieve dry mouth, suck on (sugarless) hard candy or ice chips, chew (sugarless) gum, drink water, or use a saliva substitute. Clemastine can dry up and thicken mucus in your lungs, making it more difficult to breathe and clear your lungs. To help prevent this effect, drink plenty of fluids unless otherwise directed by your doctor.If your doctor has prescribed this drug, remember that he or she has judged 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 any of these unlikely but serious side effects occur: mental/mood changes (e.g., hallucinations, irritability, nervousness), ringing in the ears, trouble urinating.Tell your doctor immediately if any of these rare but very serious side effects occur: easy bruising/bleeding, fast/irregular heartbeat, seizure.A very serious allergic reaction to this drug is rare. 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.This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.In the US -Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

PRECAUTIONS: 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. Talk to your pharmacist for more details.Before using this medication, tell your doctor or pharmacist your medical history, especially of: breathing problems (e.g., asthma, emphysema), a certain eye problem (glaucoma), heart problems, high blood pressure, liver disease, seizures, stomach problems (e.g., ulcers, blockage), overactive thyroid (hyperthyroidism), urination problems (e.g., trouble urinating due to enlarged prostate, urinary retention).This drug may make you dizzy or drowsy or cause blurred vision. Do not drive, use machinery, or do any activity that requires alertness or clear vision until you are sure you can perform such activities safely. Limit the use of alcohol and certain other medications that cause drowsiness. (See also Drug Interactions.)To minimize dizziness and lightheadedness, get up slowly when rising from a sitting or lying position.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.The elderly may be more sensitive to the effects of this drug, especially dizziness, drowsiness, and low blood pressure.Children may be more sensitive to the effects of antihistamines. In young children, this medication may cause agitation/excitement instead of drowsiness.If you are pregnant, consult your doctor before using this medication. Discuss the risks and benefits with your doctor.This drug passes into breast milk and may have undesirable effects on a nursing infant. Consult your doctor before breast-feeding.

Report Problems to the Food and Drug Administration   You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088. Need help identifying pills and medications? Use the pill identifier tool on RxList.