Use
Phenindamine tartrate,2,3,4,9-tetrahydro-2-methyl-9-phenyl-1H-indeno[2, 1-c]pyridine bitartrate, occurs as a creamy-white powder, usuallywith a faint odor and sparingly soluble in water (1:40). A 2%aqueous solution has a pH of about 3.5. It is most stable inthe pH range of 3.5 to 5.0 and is unstable in solutions of pH 7or higher. Oxidizing substances or heat may cause isomerizationto an inactive form.Structurally, phenindamine can be regarded as an unsaturatedpropylamine derivative, in that the rigid ring systemcontains a distorted, trans-alkene. Like the other commonlyused antihistamines, it may produce drowsiness and sleepiness;it may also cause a mildly stimulating action in somepatients and insomnia when taken just before bedtime.