Irtemazole

A single 50 mg dose of irtemazole was given orally to ten healthy male volunteers. The onset of effects was tested. Plasma uric acid began to decrease 15 to 25 min after irtemazole was administrated. Renal uric acid excretion and uric acid clearance increased 10 to 20 min after drug administration. Maximal renal uric acid excretion (mean 197.4 mg/h) and maximal uric acid clearance (mean 78.4 ml/min) were reached after 15 to 55 min. No side effects were observed. The effects of irtemazole occur earlier than those of benzbromarone. The therapeutic effects of long-term therapy remain to be investigated.

Following a single dose of 50 mg irtemazole per os, plasma uric acid levels decreased after 1 h and fell to 53.5% of the original value within 6-12 h. Renal uric acid excretion increased up to 66 mg/h 30 min after drug application and reached its maximum of 151 mg/h 30 min later. Uric acid clearance also increased after 30 min and reached its maximum of 56 ml/min after 60 min. The response of the kidney to irtemazole is faster than to benzbromarone or probenecid. Lowering of plasma uric acid has a shorter-lasting effect than benzbromarone or probenecid. At 24 h after the application of 50 mg irtemazole the decrease of the plasma uric acid was between 15.4% and 30.0%, or 24.7% on average. Three days after the application the basic plasma uric acid levels were reached again.