Pharmacotherapeutic group: Hypnotics and sedatives.
ATC vet code: QN05CM93
Pharmacodynamic properties
Romifidine is an alpha-2-agonist of the imino-imidazolidine class. It exerts sedative and analgesic effects. Its sedative effect is induced by stimulation of alpha-2-adrenoreceptors in the central nervous system. The substance possesses a strong specific affinity for these receptors.
After administration of romifidine, blood pressure increases initially due to its effect on peripheral postsynaptic α1-receptors in combination with activation of extrajunctional α2b-adrenoceptors located on smooth muscle cells in the arteriolar resistance vessels. Subsequently, blood pressure decreases due to the effect on peripheral presynaptic receptors (inhibition of noradrenaline release from sympatic nerve endings) and decrease of sympathetic tone resulting in vasodilatation.
Pharmacokinetic properties
Approximately 20% of romifidine is bound to plasma proteins. Romifidine is found predominantly in the kidney and muscle, whereas the liver contains only traces of the parent compound. The main hepatic metabolites, SHT 2130, STH 2337 and ESR 1235, have been shown to be pharmacologically inactive.
Following intravenous injection, romifidine is rapidly eliminated: approximately 80% of the administered dose is eliminated via urine and the remainder via the faeces.