RespiVent Dosepack DF

Chlorpheniramine maleate is an alkylamine-type antihistamine. This group of antihistamines is among the most active histamine antagonists and is generally effective in relatively low doses.

Methscopolamine nitrate is a quaternary ammonium derivative of the anticholinergic scopolamine which possesses the peripheral actions of the belladonna alkaloids, but does not exhibit the central actions because of its lack of ability to cross the blood-brain
barrier. Its antimuscarinic effect causes inhibition of salivary secretions, reduction in volume and total acid content of gastric secretion, and inhibition of gastrointestinal motility. It is poorly and unreliably absorbed. Drug effects appear in about one hour and
persist for about 4 to 6 hours. It is excreted primarily in the urine and bile, or as unabsorbed drug in feces.

This product is contraindicated in patients with hypersensitivity to methscopolamine nitrate and chlorpheniramine maleate. RespiVent™ DF is contraindicated in patients with severe hypertension, severe coronary artery disease, and in nursing mothers.
RespiVent™ DF is also contraindicated in patients with narrow-angle glaucoma, and peptic ulcer.

Antihistamines may cause excitability, especially in children. At dosages higher than the recommended dose, nervousness, dizziness, or sleeplessness may occur. Do not exceed recommended dosage. Methscopolamine nitrate may produce drowsiness or blurred vision. The patient should be cautioned regarding activities requiring mental alertness such as operating a motor vehicle or performing hazardous work while taking RespiVent™ DF.

Co-administration of sildenafil citrate and other organic nitrates has been shown to potentiate the hypotension effects of nitrates. Co-administration of RespiVent™ DF and sildenafil citrate has not been studied. Therefore, the use of sildenafil citrate and RespiVent™ DF together is not recommended.

General

RespiVent™ DF should be used with caution in patients with diabetes mellitus, hypertension, and cardiovascular disease.  Antihistamines may cause drowsiness, and ambulatory patients who operate machinery or motor vehicles should be cautioned accordingly. Methscopolamine nitrate should be used with caution in the elderly and all patients with autonomic neuropathy, hepatic or renal disease, or ulcerative colitis.

Drug Interactions

Additive anticholinergic effects may result from concomitant use with antipsychotics, tricyclic antidepressants, and other drugs with anticholinergic effects. Concomitant administration with antacids may interfere with the absorption of methscopolamine nitrate.

Carcinogenesis, Mutagenesis, Impairment of Fertility

Animal studies to assess the long-term carcinogenic and mutagenic potential or the effect on fertility in animals or humans have not been performed.

Pregnancy Category C

It is not known whether RespiVent™ DF can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity.  RespiVent™ DF should be given to a pregnant woman only if clearly needed.

Nursing Mothers

It is not known whether this combination drug is excreted in human milk.

Pediatric Use

The safety and effectiveness in children under 12 years of age have not been established.

Geriatric Use

The elderly (60 years and older) are more likely to experience adverse reactions to methscopolamine.

Adverse reactions include drowsiness, lassitude, nausea, giddiness, dryness of mouth, blurred vision, and increased irritability or excitement (especially in children). Antihistamines and anticholinergics may cause drowsiness, dizziness, blurred vision, and excessive dryness of the nose, throat, and mouth.