Prizidilol (also known as SKF 92657) is arylpyridazinylhydrazine derivative patented by Smith Kline and French Laboratories Ltd. as an antihypertensive agent. In clinical trials, Supine and standing blood pressure measured 24--27 h after drug intake was reduced Slight but significant decreases in heart rate were seen after moderate doses of prizidilol. A more pronounced blood pressure reduction was noticed 2--7 h after drug administration. Prizidilol was well tolerated, although dizziness and tiredness were reported by four patients and edema by two.