Antihypertensives: Central alpha 2 receptor agonists

1. AE: sedation, dry moth mc; dizzy depression (central effects); orthostasis uncommon; Na and H2O retention, give w/ diuretics; rebound HTN if you stop w/o tapering; bradycardia;

2. AE: methyldopa-> hepatitis or immune hemolytic anemia Coombs positive; periodically check LFTs and CBC

3. AE: long term use leads to decrease sensitivity of alpha 2 receptors to NE so when NE binds it does not inhibit the NE release -> NE up and more HTN

4. clonidine

4.1. PO and transdermal system

5. guanfacine

5.1. rarely used, more for children w/ tic disorders, severe impulsivity or insomnia; transdermal may have less adverse effects than oral route

6. methyldopa

6.1. metabolized into alpha 2 agonist; reserved for moderate to severe cases; use with diuretic (aboid Na and water retention)

6.2. Used for HTN IN PREGNANCY

7. guanabenz

8. MOA: stimulate alpha2, reduction in symp outflow, more vagal tone, reduces PVR/BP

8.1. lowers PRV, HR, cardiac output which may lead to renin activation and eventually water and sodium retention if given alone