Ketanserin (INN, USAN, BAN) (brand name Sufrexal; former code name R41468) is a drug used clinically as an antihypertensive agent and in scientific research to study the serotonin system; specifically, the 5-HT2A receptor. It was discovered at Janssen Pharmaceutica in 1980.
Uses
Antihypertensive
It is classified as an antihypertensive by the World Health Organization and the National Institute of Health.
It has been used to reverse hypertension caused by protamine (which in turn was administered to reverse the effects of heparin overdose).
The reduction in hypertension is not associated with reflex tachycardia.
It has been used in cardiac surgery.
As a radioligand
With tritium (3H) radioactively labeled ketanserin is used as a radioligand for the serotonin 5-HT2A receptor, e.g. in receptor binding assays and autoradiography. This radiolabeling enables the study of the serotonin-2A receptor distribution in the human brain.
An autoradiography study of the human cerebellum has found an increasing binding of H-3-ketanserin with age (from below 50 femtomol per milligram tissue at around 30 years og age to over 100 above 75 years). The same research team found no significant correlation with age in their homogenate binding study.
As a blocker with another radioligand
Ketanserin has also been used with carbon (11C) radioactively labeled NNC112 in order to image cortical D1 receptors without contamination by 5-HT2A receptors.
Pharmacology
Ketanserin is a high-affinity antagonist of the 5-HT2A receptor (Ki = 2-3 nM). However, it also blocks the H1 receptor with high affinity (Ki = 2 nM). In addition, ketanserin less potently antagonizes the α1-adrenergic (Ki = ~40 nM), α2-adrenergic = ~200 nM), 5-HT1D (Ki = ? nM), 5-HT2B (Ki = ? nM), 5-HT2C (Ki = 100 nM), 5-HT6 (Ki = ~300 nM), 5-HT7 (Ki = ? nM), D1 (~300 nM), and D2 (Ki = ~500 nM) receptors. It also blocks the vesicular monoamine transporter (VMAT).
See also
- Lidanserin
- Pirenperone
- RH-34
- Risperidone
- Ritanserin
- Setoperone
- Volinanserin