Antihypertensive Agents

Question 1

Broad Categories of Antihypertensive Agents

Answer 1

• Adrenergic agents: Clonidin, Doxazasin (alpha 1 blocker), Labetalol (alpha and beta blocker)
• Angiotension-converting enzyme (ACE) inhibitors: Captopril, Enalapril, Lisinopril
• Angiotension II receptor antagonists (ARBs): Losartan
• Calcium Channel Blockers (see Antianginal drugs)
• Diuretics (see diuretic drugs)
• Vasodilators: Hydralazine, Sodium Nitroprusside

Question 2

Adrenergic Agonists

Answer 2

Key Drug: CLONIDINE

Alpha 2 Agonists
- Mechanism of Action and Drug Effects: Synthetic Stimulation of Alpha 2 receptors in CNS; Peripherally causes kidneys to reduce the amount of renin produced

• Topical/patch and Oral
• Indications: Hypertension (not first line), Opioid Withdrawal
• Contraindications: Allergy, hypotension, MAOIs,
  ACUTE Heart Failure
• Adverse Effects: Postural/orthostatic hypotension, hypotension, hypertension, fatigue, Dizziness,
• Interactions: Additive- Diuretics, nitrates, other antihypertensives; Competitive- MAOIs, Amphetamines

Question 3

Adrenergic-Blocking drugs

Answer 3

Key Drugs: DOZAZOSIN (alpha 1 blocker); LABETALOL (alpha and beta blocker)

• Alpha Blockers
• MOA
  Block Alpha 1 receptors-Vasodilation
• Indications
  Hypertension & BPH (decrease inflamm in smooth muscle)
• Contraindications
  Allergy, hepatic & renal disease, hypotension, acute heart failure
• Adverse Effects
  Hypotension, Orthostatic Hypotension, Palpitations, Tachycardia, Chest Pain, Dizziness, Head ache
• Interactions
  Additive Effect-CNS Depressants, alcohol, BB, antihypertensives

Question 4

ACE inhibitors

Answer 4

Key Drugs: CAPTOPRIL, ENALAPRIL, LISINOPRIL - oral meds

• “PRIL”s; First line drug
• MOA
  Blocks Angiotensin-Converting enzyme
• Indications: First line drugs for Hypertension, Heart Failure
• Contraindications: K+ of > 5meq/L, Lactating Women

 - Adverse Effects
CNS-fatigue, dizziness, mood changes, HA
DRY, NONPRODUCTIVE COUGH
Hyperkalemia-promote K resorption
Hypotension

• Interactions-NSAIDs (competitive), antihypertensives (additive), lithium (lithium toxicity)

Question 5

Angiotensin II Receptor Blockers

Answer 5

Key Drug: LOSARTAN - oral med

• “Sartan”s
• MOA
  Blocks angiotensin II from binding to type 1 receptors
• Indication
  Hypertension and/or CHRONIC heart failure
• Contraindication
  Pregnancy, with caution in elderly, renal dysfunction
• Adverse Effects
  Upper Respiratory infections, headaches, dizziness, hypotension, hyperkalemia
• Interactions
  NSAID, lithium, rifampin, K+ supplements

Question 6

Vasodilators

Answer 6

Key Drug: HYDRALAZINE, SODIUM NITROPRUSSIDE (breaks down into cyanide) - oral and IV form

• Direct acting vasodilators
• Mechanism of action: Act directly on vascular smooth muscle
• Indications: Management of hypertension; hypertensive crisis
• Contraindications
• Hypotension, head injury, ACUTE MI, CAD, heart failure (with diastolic dysfunction…which is when heart has become so stiff it can’t relax even when encouraged to do so)
• Adverse Effects
  Dizziness, HA, orthostatic hypotension, Na+ and H2O retention, dysrhythmias, hyperglycemia in diabetics
• Interactions
  Other antihypertensives