Protriptyline HCl is N -methyl-5 H -dibenzo[ a,d ]-cycloheptene-5-propanamine hydrochloride. Its molecular formula is C19H21N·HCl and its structural formula is:
Protriptyline HCl, a dibenzocycloheptene derivative, has a molecular weight of 299.84. It is a white to yellowish powder that is freely soluble in water and soluble in dilute HCl. Protriptyline HCl is supplied as 5 mg or 10 mg film-coated tablets. Inactive ingredients are anhydrous lactose, carnauba wax, corn starch, dibasic calcium phosphate, hydroxypropyl cellulose, hydroxypropyl methylcellulose, magnesium stearate, microcrystalline cellulose, polyethylene glycol, polysorbate 80, propylene glycol, sodium starch glycolate, titanium dioxide, and the 5 mg tablets contain FD&C Yellow #6 and FD&C Red #40; the 10 mg tablets contain D&C Yellow #10 and D&C Red #30.
Protriptyline hydrochloride is an antidepressant agent. The mechanism of its antidepressant action in man is not known. It is not a monoamine oxidase inhibitor, and it does not act primarily by stimulation of the central nervous system.
Protriptyline has been found in some studies to have a more rapid onset of action than imipramine or amitriptyline. The initial clinical effect may occur within one week. Sedative and tranquilizing properties are lacking. The rate of excretion is slow.