Penbutolol

Penbutolol (Levatol, Levatolol, Lobeta, Paginol, Hostabloc, Betapressin) is a medication in the class of beta blockers, used in the treatment of high blood pressure. Penbutolol is able to bind to both beta-1 adrenergic receptors and beta-2 adrenergic receptors (the two subtypes), thus making it a non-selective β blocker [1]. Penbutolol is a sympathomimetic drug with properties allowing it to act as a partial agonist at β adrenergic receptors [2]. Penbutolol has also been found to be one of very few compounds that are 5-HT1A antagonists. 5-HT1A receptors are activated by serotonin, which have many different actions in different species. This makes it difficult to create generalizations about serotonin and its effects [1].