Clemastin actavis

Overdose

Antihistamine overdosage reactions may vary from central nervous system depression to stimulation. In children, stimulation predominates initially in a syndrome which may include exclient, hallucinations, ataxia, incoordination, muscle twitching, athetosis, hyperthermia, cyanosis convulsions, tremors, and hyperreflexia followed by postictal depression and cardio-respiratory arrest. Convulsions in children may be preceded by mild depression. Dry mouth, fixed dilated pupils, flushing of the face, and fever are common. In adults, CNS depression, ranging from drowsiness to coma, is more common. The convulsant dose of antihistamines lies near the lethal dose. Convulsions indicate a poor prognosis.

In both children and adults, coma and cardiovascular collapse may occur. Deaths are reported especially in infants and children.

There is no specific therapy for acute overdosage with antihistamines. The latent period from ingestion to appearance of toxic effects is characteristically short (1/2-2 hours). General symptomatic and supportive measures should be instituted promptly and maintained for as long as necessary.

Since overdoses of other classes of drugs (i.e. tricyclic antidepressants) may also present anticholinergic symptomatology, appropriate toxicological analysis should be performed as soon as possible to identify the causative agent.

In the conscious patient, vomiting should be induced even though it may have occurred spontaneously. If vomiting cannot be induced, gastric lavage is indicated. Adequate precautions must be taken to protect against aspiration, especially in infants and children. Charcoal slurry or other suitable agents should be instilled into the stomach after vomiting or lavage. Saline cathartics or milk of magnesia may be of additional benefit.

In the unconscious patient, the airway should be secured with a cuffed endotracheal tube before attempting to evacuate the gastric spans. Intensive supportive and nursing care is indicated, as for any comatose patient.

If breathing is significantly impaired, maintenance of an adequate airway and mechanical support of respiration is the most effective means of providing adequate oxygenation.

Hypotension is an early sign of impending cardiovascular collapse and should be treated vigorously. Although general supportive measures are important, specific treatment with intravenous infusion of a vasopressor titrated to maintain adequate blood pressure may be necessary.

Do not use with CNS stimulants.

Convulsions should be controlled by careful administration of diazepam or a short-acting barbiturate, repeated as necessary. Physostigmine may also be considered for use in controlling centrally mediated convulsions.

Ice packs and cooling sponge baths, not alcohol, can aid in reducing the fever commonly seen in children. A more detailed review of antihistamine toxicology and overdose management is available in Gosselin, R.E., et. al., "Clinical Toxicology of Commercial Products."

Contraindications

Antihistamines are contraindicated in patients hypersensitive to the drug or to other antihistamines of similar chemical structure (see PRECAUTIONS: DRUG INTERACTIONS).

Antihistamines should not be used in newborn or premature infants. Because of the higher risk of antihistamines for infants generally and for newborns and prematures in particular, antihistamine therapy is contraindicated in nursing mothers (see PRECAUTIONS-Nursing Mothers).

Undesirable effects

The most frequent adverse reactions are italicized:

Sedation, sleepiness, dizziness, disturbed coordination, fatigue, confusion, restlessness, excitation, nervousness, tremor, irritability, insomnia, euphoria, paresthesia, blurred vision, diplopia, vertigo, tinnitus, acute labyrinthitis, hysteria, neuritis, convulsions.

Epigastric distress, anorexia, nausea, vomiting, diarrhea, constipation.

Thickening of bronchial secretions, tightness of chest and wheezing, nasal stuffiness.

Hypotension, headache, palpitations, tachycardia, extrasystoles.

Hemolytic anemia, thrombocytopenia, agranulocytosis.

Urinary frequency, difficult urination, urinary retention, early menses.

Urticaria, drug rash, anaphylactic shock, photosensitivity, excessive perspiration, chills, dryness of mouth, nose and throat.

Therapeutic indications

Clemastin Actavise Fumarate Syrup is indicated for the relief of symptoms associated with allergic rhinitis such as sneezing, rhinorrhea, pruritus and lacrimation. Clemastin Actavise Fumarate Syrup is indicated for use in pediatric populations (age 6 years through 12) and adults (see DOSAGE AND ADMINISTRATION).

It should be noted that Clemastin Actavise is indicated for the relief of mild uncomplicated allergic skin manifestations of urticaria and angioedema at the 2 mg dosage level only.

Name of the medicinal product

Qualitative and quantitative composition

Special warnings and precautions for use

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.

Clemastin Actavise has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc.).

Patients should be warned about engaging in activities requiring mental alertness such as driving a car or operating appliances, machinery, etc.

Antihistamines are more likely to cause dizziness, sedation, and hypotension in elderly patients.

Clemastin Actavise fumarate should be used with caution in patients with: history of bronchial asthma, increased intraocular pressure, hyperthyroidism, cardiovascular disease, and hypertension.

Teratogenic Effects

Although quantitative determinations of antihistaminic drugs in breast milk have not been reported, qualitative tests have documented the excretion of diphenhydramine, pyrilamine, and tripelennamine in human milk.

Because of the potential for adverse reactions in nursing infants from antihistamines, a decision should be made whether to discontinue nursing or to discontinue the drug.

The safety and efficacy of Clemastin Actavise Fumarate Syrup has been confirmed in the pediatric population (age 6 years through 12). Safety and dose tolerance studies have confirmed pediatric patients 6 through 11 years tolerated dosage ranges of 0.75 to 2.25 mg Clemastin Actavise. In pediatric patients particularly, antihistamines in overdosage may produce hallucinations, convulsions and death. Symptoms of antihistamine toxicity in pediatric patients may include fixed dilated pupils, flushed face, dry mouth, fever, excitation, hallucinations, ataxia, incoordination, athetosis, tonic-clonic convulsions, and postictal depression (see OVERDOSAGE).

Teratogenic Effects

Although quantitative determinations of antihistaminic drugs in breast milk have not been reported, qualitative tests have documented the excretion of diphenhydramine, pyrilamine, and tripelennamine in human milk.

Because of the potential for adverse reactions in nursing infants from antihistamines, a decision should be made whether to discontinue nursing or to discontinue the drug.

The safety and efficacy of Clemastin Actavise Fumarate Syrup has been confirmed in the pediatric population (age 6 years through 12). Safety and dose tolerance studies have confirmed pediatric patients 6 through 11 years tolerated dosage ranges of 0.75 to 2.25 mg Clemastin Actavise. In pediatric patients particularly, antihistamines in overdosage may produce hallucinations, convulsions and death. Symptoms of antihistamine toxicity in pediatric patients may include fixed dilated pupils, flushed face, dry mouth, fever, excitation, hallucinations, ataxia, incoordination, athetosis, tonic-clonic convulsions, and postictal depression (see OVERDOSAGE).

Dosage (Posology) and method of administration

DOSAGE SHOULD BE INDIVIDUALIZED ACCORDING TO THE NEEDS AND RESPONSE OF THE PATIENT.

For Symptoms of Allergic Rhinitis - The starting dose is 2 teaspoonfuls (1 mgClemastin Actavise) twice daily. Dosage may be increased as required, but not to exceed 12 teaspoonfuls daily (6 mg Clemastin Actavise).

For Urticaria and Angioedema - The starting dose is 4 teaspoonfuls (2 mg Clemastin Actavise) twice daily, not to exceed 12 teaspoonfuls daily (6 mg Clemastin Actavise).