see also: [[haemorrhagic stroke]], [[Nicardipine]], [[Hypertensive Emergency]] see: [RMH Urapidil guideline](x-devonthink-item://1AEAAC5E-9956-4D41-8C55-B6F36D940DD2) > [Drug_Class:: antihypertensive] > [Indications:: [[haemorrhagic stroke]]] ## Mechanism  - α1-antagonist (vasodilation and ↓ PVR)  - 5HT1A receptor agonist (↓ sympathetic tone, ↑ renal blood flow, suppresses reflex tachycardia  - does *not* elicit reflex tachycardia (weak β antagonist activity) ## Contraindications - coarctation of the aorta - AV shunt (unless dialysis hsunt is not haemodynamically active ### Precautions > [!warning] Reduce dose if impaired renal or function or frailty - use with caution with other antihypertensive therapy - contains propylene glycol; high doses or prlonged use can lead ot hyperosmolality, lactic acidosis, ATN - liver impairment may require dose reduction, and predominately metabolised in liver - moderate to severe renal impairment may require dose reduction ### Use in pregnancy - crosses the placenta. reproductive studies have shown reporductive toxicity without teratogencty - although evaluated for treating pre-eclampsia and severe HTN in pregnancy, other agents are preferred - not recommended for breastfeeding; not known if present in breast milk ## pharmacokinetics - onset of action within 5 min of IV bolus - half-life : 2.7 hours ## Dose > comes in 25mg/5mL and 50mg/10mL ampoules for a dose of 5mg/mL. > (27.35mg urapidil hydrochloride is 25mg urapidil) ### Bolus doses - initial dose **5-10mg IV over 20 seconds** *(1-2mL)* - subsequent doses 5-25mg IV (1-5mL) ### Continuous infusion - if SBP >180 or no bolus given, commence at **2mg/min** (*120mg/hour*) - if bolus given or SBP <180, commence at 30-50mg/hour (6-10mL/hour) | SBP | Action | | --------- | ------------- | | \< 120 | stop infusion | | 121 - 130 | down-titrate | | 131-160 | no change | | \> 160 | up-titrate | ## Monitoring - monitor BP and HR Q5-15 min during titration - continue until 2 stable readings - upon cessation of urapidil, monitor BP and HR at 30-min intervals for at least 2 hours