Drug and placebo preparations
| Bolus (syringe 1) | Continuous infusion (syringe 2) | |||
| Intravenous bolus (dose) | Intravenous bolus (rate) | Intravenous continuous (dose) | Intravenous continuous (rate) | |
| Treatment | 12.5 mL (ie, 10 mg of sildenafil). Diluted with 5% glucose to a total of 15 mL Marked as syringe 1 | 45 mL/h; that is, to run over 20 min | 2.5 mg sildenafil as a 2-hour continuous infusion, diluted to a total of 50 mL in 5% glucose Marked as syringe 2 | 25 mL/hour, that is, to run over 2 hours |
| Placebo | 15 mL 5% glucose Marked as syringe 1 | 45 mL/hour; that is, to run over 20 min | 50 mL 5% glucose Marked as syringe 2 | 25 mL/hour, that is, to run over 2 hours |