It has no analgesic or addictive properties. The onset of antitussive action occurs in 15 to 30 minutes after administration and is of long duration. Phenylpropanolamine stimulates both alpha and beta adrenergic receptors, similar to ephedrine. Part of its peripheral action is indirect and is due to the displacement of norepinephrine from storage sites, but it also has direct effect on the adrenergic receptors. Brompheniramine maleate is a histamine antagonist, specifically an H1-receptor blocking agent belonging to the alkylamine class of antihistamines.
Antihistamines appear to compete with histamine for receptor sites on effector cells.
This combination drug is indicated for the relief of coughs and upper respiratory symptoms, including nasal congestion, associated with allergy or the common cold. Do not use in newborns, in premature infants, in nursing mothers, in patients with severe hypertension or severe coronary artery disease, or in those receiving MAO inhibitors. Antihistamines should not be used to treat lower respiratory tract conditions including asthma. A persistent cough may be a sign of a serious condition. If cough persists for more than one week, tends to recur or is accompanied by fever, rash or persistent headache, consult a physician.