Antihypertensive agents contraindications

If a stroke patient receives intravenous (IV) thrombolysis, care often continues in the ED until the patient arrives in the ICU. Close monitoring must continue during this time, with special attention to the blood pressure. The blood pressure is most commonly checked via an arm cuff, since the placement of invasive lines (e.g., arterial catheterization) is relatively contraindicated once the patient has received intravenous thrombolysis (unless the situation is emergent and mandates such treatment). The systolic pressure must not exceed 185 mm Hg, and the diastolic pressure limit should be 110 mm Hg. Should the blood pressure exceed these limits, IV antihypertensive agents should be administered. IV pushes of labetolol (10-20 mg over 1-2 minutes) may be effective, but if patients are refractory to these initial measures then a continuous infusion of labetolol (0.5-2.0 mg/minute), nicardipine (5-15 mg/hour), or nitro-prusside (0.25-10 mg/kg/minute) may be necessary to keep the patient s blood pressure within the range. There will be a more detailed discussion of these antihypertensive agents, including their side effect profiles, later in this chapter. 

Beta blockers Nonspecific beta blockers (block both Pj and P receptors) have been used as first-step antihypertensive agents. Because these agents block P receptors as well as Pj receptors, bronchospasm may occur. Newer agents are P,-specific and are not contraindicated in asthmatic patients. 

The angiotensin-converting enzyme (ACE) inhibitors are recommended when the preferred first-line agents (diuretics or (S-blockers) are contraindicated or ineffective. Despite their wide-spread use, it is not clear if antihypertensive therapy with ACE inhibitors increases the risk of other major diseases. 

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