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Let’s talk Blood Pressure and Antihypertensive medications. A normal BP is defined as a systolic pressure of less than 120 over a diastolic pressure of less than 80. If the blood pressure ranges from 120-139 over 80-90, the patient is considered to be pre-hypertensive. Stage 1 hypertension is classified by a pressure of 140-159 over 90-99. Stage 2 hypertension is defined as 160-180 over 100-110. Anything above 180 over 110 is often considered a hypertensive crisis. Sometimes this is narrowed further into hypertensive urgency or hypertensive emergency depending on the level of end-organ involvement, or how symptomatic the patient is. Sometimes, patients can experience relative hypotension at “normal” pressures when they are used to living with a very high blood pressure.
To treat hypertension, there are three main classes of antihypertensives, which we often supplement with other medications such as diuretics.
First is ACE Inhibitors, or medications that end in -PRIL (Enalapril, Lisinopril, Captopril). These work by inhibiting the conversion of angiotensin 1 to angiotensin 2, thus preventing fluid retention and vasoconstriction. Common side effects include dizziness, headache, drowsiness, low BP, rash, and a dry, hacking (very annoying) cough.
Second is Beta Blockers which act to slow heart rate and heart muscle contractility. These medications end in -OLOL, including propranolol, atenolol, metoprolol, esmolol, and timolol. Beta blockers can also cause dizziness, headache, fatigue, and low BP, and can also cause a masking of symptoms of hypoglycemia (so take caution in diabetic patients). They can also counteract bronchodilators in asthmatic patients, so keep this in mind.
Finally, calcium channel blockers decrease the contractility of the heart by blocking calcium uptake in the cardiac muscle. Most of them end is -IPINE with a couple exceptions. There’s Nifedipine, Nicardipine, and Amlodipine, but also Verapamil and Diltiazem. Calcium Channel Blockers can cause low BP and heart rate as well as drowsiness, orthostatic hypotension, and some GI symptoms.
Choosing an antihypertensive depends on the etiology of the patient’s hypertension and will be determined by the provider. It is important that you know how to evaluate for side effects and effectiveness of the medication.
Date Published - Apr 30, 2018
Date Modified - May 1, 2018