TUSEPTIL

Guaifenesin is an expectorant the action of which promotes or facilitates the removal of secretions from the respiratory tract. The precise mechanism of action of guaifenesin is not known; however, it is thought to act as an expectorant by increasing the volume and reducing the viscosity of secretions in the trachea and bronchi. In turn, this may increase the efficiency of the cough reflex and facilitate removal of the secretions. Guaifenesin is over-the-counter drug for the treatment of cough and common cold.

Diphenhydramine is an ethanolamine-derivative antihistamine. It is an antihistamine with anticholinergic and marked sedative effects. It acts by inhibiting the effects on H₁-receptors. Diphenhydramine is effective in reducing sleep onset (i.e., time to fall asleep) and increasing the depth and quality of sleep.

Phenylpropanolamine is a sympathomimetic agent which is used as a decongestant and appetite suppressant. It was commonly used in prescription and over-the-counter cough and cold preparations. Although originally thought to act as a direct agonist of adrenergic receptors, phenylpropanolamine was subsequently found to show only weak or negligible affinity for these receptors, and has been instead characterized as an indirect sympathomimetic which acts by inducing norepinephrine release and thereby activating adrenergic receptors.