Therapeutics of HTN pt. 4 Flashcards
Direct arterial vasodilators agents
Hydralazine, minoxidil
Are direct arterial vasodilators a last line therapy for HTN
Yes
Who are direct arterial vasodilators reserved for
Reserved for pts w/ special indications or very difficult to control BP (i.e. severe CKD or hemodialysis)
Which of the direct arterial vasodilators is more potent
Minoxidil is more potent than hydralazine
What is a requirement with direct arterial vasodilators
requires concomitant therapy w/ diuretic and B blocker
which of the direct arterial vasodilators is more preferred
Hydralazine is preferred over minoxidil
If a pt is on minoxidil, which class of diuretic must the pt be on
Loop diuretic
Direct arterial vasodilators AEs
- Palpitations, tachycardia, chest pain, GI SEs, headache, hematologic dyscrasias, hepatotoxicity, fluid retention
- Hydralazine specific - lupus like syndrome/rash
- Minoxidil specific - hair growth
frequency of hydralazine
2-4/day
frequency of minoxidil
1-3/day
what are the boxed warning summaries of minoxidil
- may cause pericarditis and pericardial effusion that may progress to tamponade
- may increase oxygen demand and exacerbate angina pectoris
what should be used before minoxidil is ever added
maximum therapeutic doses of a diuretic and two other antihypertensives
direct arterial vasodilators use caution with:
CVA, renal impairment, CAD, liver disease, SLE
alpha 1 blockers agents
doxazosin, prazosin, terazosin
what is the use of alpha 1 blockers
- NEVER considered 1st line for HTN
- 2nd line for pts with concomitant BPH
what is alpha 1 blockers associated with (esp. in elderly)
orthostatic hypotension
central alpha 2 agonists agents
clonidine, methyldopa, guanfacine
what is the use of central alpha 2 agonists
last line for htn due to AEs
which of the central alpha 2 agonists has the most severe AEs
clonidine
central alpha 2 agonists AEs
CNS depression, dizziness, fatigue, anticholinergic effects, bradycardia, reflex tachycardia, fluid retention
why should central alpha 2 agonists never be abruptly stopped
abrupt cessation causes rebound htn
what central alpha 2 agonist is preferred in pregnancy
methyldopa
clonidine dosage forms and strength
- PO: 0.1-0.2 mg BID or TID (max 2.4 mg/day)
- Transdermal weekly patch: 0.1-0.3 mg/24h
what is an advantage the clonidine patch has over the oral route
lower risk of rebound htn and improved adherence with patch
methyldopa strength and frequency
250-500 mg BID
guanfacine strength and frequency
0.5-2mg daily
what is the process to titrating off clonidine
- slow wean; half dose every 2-3 days
- concomitant B blocker prescribed
- wean B blocker several days prior to clonidine wean
what is the process of transitioning from oral clonidine to transdermal patch
- overlap oral regimen for 3-4 days
- Day 1: place patch, administer 100% of oral clonidine dose
- Day 2: administer 50% of oral dose
- Day 3: administer 25% of oral dose
- Day 4: patch only
what is the process of transitioning from clonidine patch to oral route
consider starting oral clonidine no sooner than 8 hours after patch removal
what if pt is not at BP goal?
- consider nighttime dosing of one antihypertensive (except diuretics)
- assess adherence
- educate on diet, exercise, smoking cessation
- rule out white coat htn
- d/c interfering substances
- pt may have resistant htn
what are the risk factors of resistant htn
older age, obesity, CKD, diabetes, AA
what is step 1 of AHA stepwise guidance for management of resistant htn
- maximize lifestyle interventions; optimize 3-drug (ACEi or ARB, CCB, and diuretic)
what is step 2 of AHA stepwise guidance for management of resistant htn
- substitute optimized thiazide-like diuretic (chlorthalidone, indapamide)
what is step 3 of AHA stepwise guidance for management of resistant htn
- add mineralocorticoid receptor antagonist (spironolactone, eplerenone)
what is step 4 of AHA stepwise guidance for management of resistant htn
- add BB (or diltiazem depending on HR) if HR >70 bpm
consider central alpha 2 agonist (clonidine or guanfacine at bedtime) if BB CI and/or HR <70 bpm
what is step 5 of AHA stepwise guidance for management of resistant htn
- add hydralazine
what is step 6 of AHA stepwise guidance for management of resistant htn
- substitute minoxidil for hydralazine