Clemastine fumarate tablets are also indicated for the relief of mild, uncomplicated allergic skin manifestations of urticaria and angioedema.
It should be noted that clemastine is indicated for the dermatologic indications at the 2.68 mg dosage level only.
Dosage and Administration
Dosage should be individualised according to the needs of each patient
The recommended starting dose is 1.34 mg (1/2 tablet) twice daily. Dosage may be increased as required. Clemastine fumarate tablets are recommended for the dermatologic indications at the 2.68 mg dosage level only.
The maximum recommended dosage is 2.68mg three times daily. Many patients respond favorably to a single dose which may be repeated as required, but not to exceed three tablets daily.
Supply
Clemastine fumarate tablets, USP are available as:
2.68 mg: Round, white tablets, scored, debossed GG 160 on one side and plain on the reverse side and supplied as:
NDC 0781-1359-01 bottles of 100
NDC 0781-1359-05 bottles of 500
NDC 0781-1359-10 bottles of 1000
Store below 25° C. Dispense in a tight, light-resistant container
Side Effects
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 fumarate.
The most frequent adverse reactions are underlined.
General: Urticaria, drug rash, anaphylactic shock, photosensitivity, excessive perspiration, chills, dryness of mouth, nose, and throat.
Cardiovascular System: Hypotension, headache, palpitations, tachy-cardia, 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
Drug Interactions
MAO inhibitors prolong and intensify the anticholiner-gic (drying) effects of antihistamines
Warnings
Antihistamines should be used with considerable caution in patients with: narrow angle glaucoma, stenosing peptic ulcer, pyloroduo-denal obstruction, symptomatic prostatic hypertrophy, and bladder neck obstruction.
Use in Children: Safety and efficacy of clemastine fumarate have not been established in children under the age of 12 years.
Use in Pregnancy: Experience with this drug in pregnant women is inadequate to determine whether there exists a potential for harm to the developing fetus.
Use with CNS Depressants: Clemastine has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc.)
Use 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.
Use in the Elderly (approximately 60 years or older): Antihistamines are more likely to cause dizziness, sedation, and hypotension in elderly patients.
Precautions
General: Clemastine fumarate should be used with caution in patients with: history of bronchial asthma, increased intraocular pressure, hyperthyroidism, cardiovascular disease, and hypertension.
Overdose
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 occured 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 unsuccessfulgastric 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.
Contraindictions
Use 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.
Use 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).
