Carbinoxamine Maleate; Pseudoephedrine Hydrochloride
Indications: Congestion, nasal
DESCRIPTION:
Antihistamine/decongestant for oral use.
Carbinoxamine maleate (2-[p-Chloro-alpha-[2-(dimethylamino)ethoxy] benzyl] pyridine maleate) is one of the ethanolamine class of H1 antihistamines.
Pseudoephedrine HCl (Benzenemethanol, alpha-[1-(methylamino) ethyl]-, [S-(R', R')]-, HCl) is the HCl of pseudoephedrine, a naturally occurring dextrorotatory stereoisomer of ephedrine.
CLINICAL PHARMACOLOGY:
Antihistaminic and decongestant actions.
Carbinoxamine maleate possesses H1 antihistaminic activity and mild anticholinergic and sedative effects. Serum half-life for carbinoxamine is estimated to be 10 to 20 hours. Virtually no intact drug is excreted in the urine.
Pseudoephedrine HCl is an oral sympathomimetic amine that acts as a decongestant to respiratory tract mucous membranes. While its vasoconstrictor action is similar to that of ephedrine, pseudoephedrine has less pressor effect in normotensive adults. Serum half-life for pseudoephedrine is 6 to 8 hours. Acidic urine is associated with faster elimination of the drug. About one-half of the administered dose is excreted in the urine.
INDICATIONS AND USAGE:
For symptomatic relief of seasonal and perennial allergic rhinitis and vasomotor rhinitis.
Carbinoxamine maleate; pseudoephedrine HCl oral drops, syrup and tablet are immediate-release dosage forms allowing titration of dose up to four times a day.
Carbinoxamine maleate; pseudoephedrine HCl time release tablet utilizes a gradual-release mechanism providing approximately a 12-hour therapeutic effect, thus allowing twice-daily dosage.
CONTRAINDICATIONS:
Patients with hypersensitivity or idiosyncrasy to any of its ingredients. Sympathomimetic amines are contraindicated in patients with severe hypertension, severe coronary artery disease and patients on monoamine oxidase (MAO) inhibitor therapy. Antihistamines are contraindicated in patients with narrow-angle glaucoma, urinary retention, peptic ulcer and during an asthma attack.
WARNINGS:
Sympathomimetic amines should be used judiciously and sparingly in patients with hypertension, diabetes, ischemic heart disease, hyperthyroidism, increased intraocular pressure or prostatic hypertrophy (see CONTRAINDICATIONS). Sympathomimetic amines may produce CNS stimulation with convulsions or cardiovascular collapse with accompanying hypotension. The elderly (60 years and older) are more likely to exhibit adverse reactions. Antihistamines may cause excitability, especially in children. At doses higher than the recommended dose, nervousness, dizziness, or sleeplessness may occur. Do not exceed recommended dosage.
PRECAUTIONS:
General
Use with caution in patients with hypertension, heart disease, asthma, hyperthyroidism, increased intraocular pressure, diabetes mellitus and prostatic hypertrophy and hyper-reactivity to sympathomimetic amines. Antihistamines may cause drowsiness and ambulatory patients who operate machinery or motor vehicles should be cautioned accordingly.
Information for the Patient
Avoid alcohol and other CNS depressants while taking these products. Patients sensitive to antihistamines may experience moderate to severe drowsiness. Patients sensitive to sympathomimetic amines may note mild CNS stimulation. While taking these products, exercise care in driving or operating appliances, machinery, etc.
Pregnancy Category C
Animal reproduction studies have not been conducted with these products. It is also not known whether these products can cause fetal harm when administered to a pregnant woman or affect reproduction capacity. Give to pregnant women only if clearly needed.
Nursing Mothers
It is not known whether the drugs in carbinoxamine maleate; pseudoephedrine HCl are excreted in human milk. Because many drugs are excreted in human milk and because of the potential for serious adverse reactions in nursing infants, a decision should be made whether to discontinue nursing or discontinue the product, taking into account the importance of the drug to the mother.
Pediatric Use
Safety and effectiveness of carbinoxamine maleate; pseudoephedrine HCl oral drops in pediatric patients below the age of one month have not been established. Safety and effectiveness of carbinoxamine maleate; pseudoephedrine HCl syrup in pediatric patients below the age of 18 months have not been established. Safety and effectiveness of carbinoxamine maleate; pseudoephedrine HCl Tablets in pediatric patients below the age of 6 years have not been established. Safety and effectiveness of carbinoxamine maleate; pseudoephedrine HCl time release tablets in pediatric patients below the age of 12 years have not been established.
DRUG INTERACTIONS:
Antihistamines may enhance the effects of tricyclic antidepressants, barbiturates, alcohol, and other CNS depressants. MAO inhibitors prolong and intensify the anticholinergic effects of antihistamines. Sympathomimetic amines may reduce the antihypertensive effects of reserpine, veratrum alkaloids, methyldopa and mecamylamine. Effects of sympathomimetics are increased with MAO inhibitors and beta-adrenergic blockers.
ADVERSE REACTIONS:
Antihistamines: Sedation, dizziness, diplopia, vomiting, diarrhea, dry mouth, headache, nervousness, nausea, anorexia, heartburn, weakness, polyuria and dysuria and, rarely, excitability in children. Urinary retention may occur in patients with prostatic hypertrophy.
Sympathomimetic Amines: Convulsions, CNS stimulation, cardiac arrhythmias, respiratory difficulty, increased heart rate or blood pressure, hallucinations, tremors, nervousness, insomnia, weakness, pallor and dysuria.
OVERDOSAGE:
No information is available as to specific results of an overdose of these products. The signs, symptoms and treatment described below are those of H1 antihistamines and ephedrine overdose.
Symptoms
Should antihistamine effects predominate, central action constitutes the greatest danger. In the small child, symptoms include excitation, hallucination, ataxia, incoordination, tremors, flushed face and fever. Convulsions, fixed and dilated pupils, coma and death may occur in severe cases. In the adult, fever and flushing are uncommon; excitement leading to convulsions and postictal depression is often preceded by drowsiness and coma. Respiration is usually not seriously depressed; blood pressure is usually stable.
Should sympathomimetic symptoms predominate, central effects include restlessness, dizziness, tremor, hyperactive reflexes, talkativeness, irritability and insomnia. Cardiovascular and renal effects include difficulty in micturition, headache, flushing, palpitation, cardiac arrhythmias, hypertension with subsequent hypotension and circulatory collapse. Gastrointestinal effects include dry mouth, metallic taste, anorexia, nausea, vomiting, diarrhea and abdominal cramps.
Treatment
Evacuate stomach as condition warrants. Activated charcoal may be useful.
Maintain a nonstimulating environment.
Monitor cardiovascular status.
Do not give stimulants.
Reduce fever with cool sponging.
Support respiration.
Use sedatives or anticonvulsants to control CNS excitation and convulsions.
Physostigmine may reverse anticholinergic symptoms.
Ammonium chloride may acidify the urine to increase excretion of pseudoephedrine.
Further care is symptomatic and supportive.
DOSAGE AND ADMINISTRATION:
TABLE 1
Age Dose* Frequency
Carbinoxamine maleate; pseudoephedrine
HCl Oral Drops for oral use only
1-3 months 1/4 dropperful (1/4 ml) q.i.d.
3-6 months 1/2 dropperful (1/2 ml) q.i.d.
6-9 months 3/4 dropperful (3/4 ml) q.i.d.
9-18 months 1 dropperful (1 ml) q.i.d.
Carbinoxamine maleate; pseudoephedrine
HCl Syrup and Tablet
18 months-6 years 1/2 teaspoonful (2.5 ml) q.i.d.
adults and pediatric patients 6 years
and over 1 teaspoonful (5 ml) or 1 tablet q.i.d.
Carbinoxamine maleate; pseudoephedrine
HCl Time Release Tablet
adults and adolescents 12 years and over 1 tablet q.i.d.
* In mild cases or in particularly sensitive patients, less frequent or reduced doses may be adequate.