Pharmacodynamics<unk>  acts primarily as an antihistamine, or H1 receptor antagonist. It has little to no anticholinergic activity, with 180-fold selectivity for the H1 receptor over the muscarinic acetylcholine receptors (for comparison, diphenhydramine had 20-fold selectivity for the H1 receptor). In addition to its antihistamine properties,<unk>  also acts as a weak serotonin-norepinephrine-dopamine reuptake inhibitor (SNDRI). Pharmacokinetics The elimination half-life of<unk>  is 4 to 6 hours. In a clinical study, the half-life of<unk>  following intramuscular injection of 50 to 100 mg was 2.9 to 4.4 hours.
Tripelennamine
Benzoctamine
Tesofensine
Apomorphine
Bremazocine
Desomorphine
Ephedrine
Droperidol