Clemastine (By mouth)


Clemastine (kle-MAS-teen)
Treats hay fever symptoms such as runny nose, watery eyes, and hives. This medicine is an antihistamine.

Brand Name(s)

There may be other brand names for this medicine.

TopCare Dayhist Allergy, Tavist-1, Good Sense Dayhist Allergy, Tavist

When This Medicine Should Not Be Used

You should not use this medicine if you have ever had an unusual or allergic reaction to clemastine or any other antihistamine medicines. This medicine should not be taken if you are breastfeeding, or have a lung disorder such as asthma. Clemastine should not be taken with monoamine oxidase (MAO) inhibitors such as Nardil®, Parnate®, or Marplan®.

How to Use This Medicine

Tablet, Liquid
  • Your doctor will tell you how much medicine to take and how often.
  • You may take your medicine with food to avoid stomach upset.
If a dose is missed:
  • Take your medicine as soon as you remember that you have missed your dose.
  • If it is nearly time for your next dose, wait until then to take the medicine and skip the missed dose.
  • You should not use two doses at one time.

How to Store and Dispose of This Medicine

  • Keep your medicine at room temperature, away from heat, direct light, and moisture. Do not freeze the oral liquid.
  • Keep all medicine away from children.

Drugs and Foods to Avoid

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.
  • Make sure your doctor knows if you are taking other antihistamines or atropine-like drugs (Donnatal®, Lomotil®).
  • Avoid drinking alcohol while taking this medicine.
  • Make sure your doctor knows if you are taking medicines such as sleeping pills, tranquilizers, narcotic pain killers, or antidepressants while taking clemastine.

Warnings While Using This Medicine

  • If you are pregnant or breastfeeding, talk to your doctor before taking this medicine.
  • Check with your doctor before taking if you have had an allergic reaction to other antihistamines, or have glaucoma, or problems with your bladder or prostate.
  • This medicine should not be given to children under 12 years of age unless ordered by a doctor.
  • Side effects of this medicine may be more likely in children and older adults. Clemastine syrup contains alcohol.
  • This medicine may make you drowsy. Be careful when driving or operating dangerous machinery.

Possible Side Effects While Using This Medicine

Call your doctor right away if you notice any of these side effects:
  • Severe drowsiness
  • Facial flushing
  • Fainting
  • Trouble breathing
If you notice these less serious side effects, talk with your doctor:
  • Drowsiness
  • Dry mouth or throat
  • Thickening of mucus
  • Clumsiness
  • Dizziness
  • Stomach upset
  • Urinating often

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088
Review Date: 2011-02-04 Reviewed By: Keywords: ,
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