Tavist-1

For all patients taking Tavist-1 (clemastine tablets):

• If you have an allergy to clemastine or any other part of this medicine.
• If you are allergic to any drugs like this one, any other drugs, foods, or other substances. Tell your doctor about the allergy and what signs you had, like rash; hives; itching; shortness of breath; wheezing; cough; swelling of face, lips, tongue, or throat; or any other signs.
• If you have taken certain drugs used for low mood (depression) like isocarboxazid, phenelzine, or tranylcypromine or drugs used for Parkinson's disease like selegiline or rasagiline in the last 14 days. Taking Tavist-1 within 14 days of those drugs can cause very bad high blood pressure.
• If you are breast-feeding. Do not breast-feed while you take this medicine.

Children:

• If your child is a premature baby or is a newborn. Do not give Tavist-1 to a premature baby or a newborn.

This medicine may interact with other drugs or health problems.

Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take this medicine with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.

Use this medicine as ordered by your doctor. Read all information given to you. Follow all instructions closely.

• Take with or without food. Take with food if it causes an upset stomach.

What do I do if I miss a dose?

• If you take Tavist-1 on a regular basis, take a missed dose as soon as you think about it.
• If it is close to the time for your next dose, skip the missed dose and go back to your normal time.
• Do not take 2 doses at the same time or extra doses.
• Many times this medicine is taken on an as needed basis. Do not take more often than told by the doctor.

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

• Feeling sleepy.
• Dizziness.
• Belly pain.

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at 1-800-FDA-1088. You may also report side effects at http://www.fda.gov/medwatch.

If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

Applies to clemastine: compounding powder, oral syrup, oral tablet

Nervous system

Nervous system side effects have included central nervous system depression which has commonly resulted in drowsiness, dizziness, and headache. Dyskinesias have rarely been reported following chronic use of antihistamines.[Ref]

Nearly all patients experience drowsiness. This drowsiness may subside in some patients with extended use. Patients should be warned against driving, as well as concomitant ingestion with alcohol and other sedative-hypnotic drugs.

Few cases of dyskinesias and tremors, often of the face, have been reported in patients whose chronic use of antihistamines extended over a period of 3 to 10 years. Some of these cases were only partially relieved by discontinuation of the drug. Haloperidol was successful in relieving symptoms.[Ref]

Gastrointestinal

Gastrointestinal side effects have included dry mouth and constipation due to anticholinergic effects. This has occurred in up to one-third of patients.[Ref]

Cardiovascular

Cardiovascular side effects have included hypotension, tachycardia, and palpitations.[Ref]

Ocular

Ocular effects are due to the anticholinergic effects and may include blurred vision, diplopia, and dry eyes.[Ref]

Genitourinary

Genitourinary side effects have included dysuria, urinary hesitancy, decrease in urine flow, and in rare cases, acute urinary retention.[Ref]

Hematologic

Hematologic side effects that have been reported with antihistamines include bone marrow suppression, thrombocytopenia, and aplastic anemia.[Ref]

A fatal case of agranulocytosis has been reported in a patient taking chlorpheniramine, pseudoephedrine, acetaminophen, dextromethorphan, phenylpropanolamine, and aspirin. Chlorpheniramine was felt to be the cause.[Ref]

Respiratory

Respiratory side effects have included thickening of bronchial secretions, wheezing, and tightness in the chest.[Ref]

Dermatologic

At least one case of toxic pustuloderma has been reported during clemastine (the active ingredient contained in Tavist-1) therapy.[Ref]

Dermatologic side effects have included toxic pustuloderma.[Ref]

Some side effects of Tavist-1 may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.