Captopril Captopril is a fast-acting ACE inhibitor that can be administered sublingually. Abrupt and first dose hypotension is rarely seen with the administration of ACE inhibitors. The rare cases are usually observed in patients with high renin levels. This drug should be used cautiously in patients with significant renal insufficiency or who are volume depleted. Clonidine Clonidine is a centrally acting agonist, with a relatively slow onset of action that can be administered hourly to safely reduce elevated blood pressure.
Sedation is a major side effect of the drug.
It also can cause rebound hypertension upon sudden discontinuation, so it should not be used in patients in whom compliance may be an issue. This agent is an alpha and beta blocker that can be administered hourly. It also has a slower onset of action. Summary The sublingual administration of immediate-release nifedipine has been demonstrated to not only result in unreliable absorption of the drug, but also has been shown to precipitate serious, and in some cases, fatal adverse effects. Other oral agents have been shown to be safe and effective methods to lower blood pressure when used to treat cases of hypertensive urgency.