2 accepted methods:
1. 20mg slow IV or IO injection over 2 minutes. Supine BP should be taken immediately prior to and 5 - 10 minutes after administration. Additional injections of 40mg can be given every 10 minutes until desired supine BP is achieved or max dose of 300mg is given.
2. 500mg added to 250mL of D5W (1.0 mg/mL) at a rate of 2 mg/min to a max dose of 300mg. BP should be constantly monitored.