Tripelennamine hydrochloride, a H1-receptor antagonist, is a psychoactive drug and member of the pyridine andethylenediamine classes that is used as an antipruritic and first-generation antihistamine.IC50 Value:Target: Histamine H1 receptorTripelennamine can be used in the treatment of asthma, hay fever, rhinitus and urticaria.in vitro: Arterial and mixed venous blood-gas and pH measurements were made at rest before and after saline or drug administration and during incremental exercise leading to maximal exertion at 14 m/s on 3.5% uphill grade for 120 s. Galloping at this workload elicited maximal heart rate and induced exercise-induced pulmonary hemorrhage in all horses in both treatments, thereby indicating that capillary stress failure-related pulmonary injury had occurred [1].in vivo: The data obtained (median and range in brackets) in camels and horses, respectively, were as follows: the terminal elimination half-lives were 2.39 (1.91-6.54) and 2.08 (1.31-5.65) h, total body clearances were 0.97 (0.82-1.42) and 0.84 (0.64-1.17)L/h/kg. The volumes of distribution at steady state were 2.87 (1.59-6.67) and 1.69 (1.18-3.50) L/kg, the volumes of the central compartment of the two compartment pharmacokinetic model were 1.75 (0.68-2.27) and 1.06 (0.91-2.20) L/kg [2]. After intramuscular administration of 50 or 100 mg tripelennamine, mean plasma concentrations at 30 minutes were 105 and 194 ng/ml, respectively, and mean plasma t1/2 values were 2.9 and 4.4 hours, respectively [3].

References:
[1]. Manohar M, Goetz TE, Humphrey S, H1-receptor antagonist, tripelennamine, does not affect arterial hypoxemia in exercising Thoroughbreds. J Appl Physiol. 2002 Apr;92(4):1515-23.
[2]. Wasfi IA, Abdel Hadi AA, Elghazali M, Comparative disposition of tripelennamine in horses and camels after intravenous administration. J Vet Pharmacol Ther. 2000 Jun;23(3):145-52.
[3]. Yeh SY, Todd GD, Johnson RE, The pharmacokinetics of pentazocine and tripelennamine. Clin Pharmacol Ther. 1986 Jun;39(6):669-76.