Clemastine Fumarate
FDA Drug Information • Also known as: Clemastine Fumarate, Clemsza
- Brand Names
- Clemastine Fumarate, Clemsza
- Route
- ORAL
- Dosage Form
- TABLET
- Product Type
- HUMAN PRESCRIPTION DRUG
Description
DESCRIPTION Clemastine belongs to the benzhydryl ether group of antihistaminic compounds. The chemical name is (+)-(2 R )-2-[2-[[( R )- p -Chloro-α-methyl-α-phenylbenzyl]-oxy]ethyl]-1-methylpyrrolidine fumarate (1:1). C 21 H 26 C1NO∙C 4 H 4 O 4 M.W. 459.97 Each tablet for oral administration contains 2.68 mg of clemastine fumarate, USP. Inactive ingredients: colloidal silicon dioxide, corn starch, lactose monohydrate, povidone, pregelatinized starch and stearic acid. Chemical Structure
What Is Clemastine Fumarate Used For?
INDICATIONS AND USAGE Clemastine Fumarate Tablets USP, 2.68 mg are indicated for the relief of symptoms associated with allergic rhinitis such as sneezing, rhinorrhea, pruritus, and lacrimation. Clemastine Fumarate Tablets USP, 2.68 mg are also indicated for the relief of mild, uncomplicated allergic skin manifestations of urticaria and angioedema. It should be noted that clemastine fumarate is indicated for the dermatologic indications at the 2.68 mg dosage level only.
Dosage and Administration
DOSAGE AND ADMINISTRATION DOSAGE SHOULD BE INDIVIDUALIZED ACCORDING TO THE NEEDS AND RESPONSE OF THE PATIENT. Clemastine Fumarate Tablets 2.68 mg The maximum recommended dosage is one tablet three times daily. Many patients respond favorably to a single dose which may be repeated as required, but not to exceed three tablets daily.
Side Effects (Adverse Reactions)
ADVERSE REACTIONS Transient drowsiness, the most common adverse reaction associated with clemastine fumarate, occurs relatively frequently and may require discontinuation of therapy in some instances. Antihistaminic Compounds It should be noted that the following reactions have occurred with one or more antihistamines and, therefore, should be kept in mind when prescribing drugs belonging to this class, including clemastine. The most frequent adverse reactions are italicized. General: Urticaria, drug rash, anaphylactic shock, photosensitivity, excessive perspiration, chills, dryness of the mouth, nose, and throat. Cardiovascular System: Hypotension, headache, palpitations, tachycardia, extrasystoles. Hematologic System: Hemolytic anemia, thrombocytopenia, agranulocytosis. Nervous System: Sedation, sleepiness, dizziness, disturbed coordination , fatigue, confusion, restlessness, excitation, nervousness, tremor, irritability, insomnia, euphoria, paresthesias, blurred vision, diplopia, vertigo, tinnitus, acute labyrinthitis, hysteria, neuritis, convulsions. GI System: Epigastric distress, anorexia, nausea, vomiting, diarrhea, constipation. GU System: Urinary frequency, difficult urination, urinary retention, early menses. Respiratory System: Thickening of bronchial secretions, tightness of chest and wheezing, nasal stuffiness.
Warnings and Precautions
WARNINGS Antihistamines should be used with considerable caution in patients with: narrow angle glaucoma, stenosing peptic ulcer, pyloroduodenal obstruction, symptomatic prostatic hypertrophy, and bladder neck obstruction. Usage in Children Safety and efficacy of clemastine fumarate have not been established in children under the age of 12 years. Usage in Pregnancy Experience with this drug in pregnant women is inadequate to determine whether there is exists a potential for harm to the developing fetus. Usage with CNS Depressants Clemastine has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc.). Usage in Activities Requiring Mental Alertness Patients should be warned about engaging in activities requiring mental alertness such as driving a car or operating appliances, machinery, etc. Usage in the Elderly (approximately 60 years or older) Antihistamines are more likely to cause dizziness, sedation, and hypotension in elderly patients.
Drug Interactions
Drug Interactions MAO inhibitors prolong and intensify the anticholinergic (drying) effects of antihistamines.
Contraindications
CONTRAINDICATIONS Usage in Nursing Mothers Because of the higher risk of antihistamines for infants generally and for newborns and prematures in particular, antihistamine therapy is contraindicated in nursing mothers. Usage in Lower Respiratory Disease Antihistamines should not be used to treat lower respiratory tract symptoms including asthma. Antihistamines are also contraindicated in the following conditions: Hypersensitivity to clemastine fumarate or other antihistamines of similar chemical structure. Monoamine oxidase inhibitor therapy (see Drug Interactions section).
Overdosage
OVERDOSAGE Antihistamine overdosage reactions may vary from central nervous system depression to stimulation. Stimulation is particularly likely in children. Atropine-like signs and symptoms: dry mouth; fixed, dilated pupils; flushing; and gastrointestinal symptoms may also occur. If vomiting has not occurred spontaneously the conscious patient should be induced to vomit. This is best done by having him drink a glass of water or milk after which he should be made to gag. Precautions against aspiration must be taken, especially in infants and children. If vomiting is unsuccessful gastric lavage is indicated within 3 hours after ingestion and even later if large amounts of milk or cream were given beforehand. Isotonic and 1/2 isotonic saline is the lavage solution of choice. Saline cathartics , such as milk of magnesia, by osmosis draw water into the bowel and therefore, are valuable for their action in rapid dilution of bowel content. Stimulants should not be used. Vasopressors may be used to treat hypotension.
How Supplied
HOW SUPPLIED Clemastine Fumarate Tablets USP, 2.68 mg are white, round, scored tablets debossed with "NH" and "268". Tablets are packaged in bottles of 30 (NDC 64950-268-03) and 100 (NDC 64950-268-10) Store at 20° to 25°C (68° to 77°F) [See USP Controlled Room Temperature]. Dispense in a tight, light-resistant container as defined in the USP, with a child-resistant closure (as required).
About This Information
This drug information is sourced from FDA-approved labeling via the openFDA database. It is intended for educational and reference purposes only. This is not medical advice. Always consult your healthcare provider before making decisions about medication. Drug information may be updated by the FDA; check with your pharmacist for the most current information.
What are side effects?
Side effects are unwanted reactions that can occur when taking a medication. They range from mild (headache, nausea) to severe (allergic reactions, organ damage). Not everyone experiences side effects, and severity varies. Report any concerning side effects to your doctor.
What are drug interactions?
Drug interactions occur when a medication is affected by another drug, food, or supplement. Interactions can make medications less effective or cause dangerous side effects. Always tell your doctor about all medications and supplements you take.