Anti-HPN Drugs Flashcards
Sympatholytic: Alpha-adrenoceptor Antagonist
A. Alpha-adrenoceptor Antagonist - not recommended for initial treatment of hypertension
* Doxazosin
* Prazosin
* Terazosin
S/E: Reflex Tachycardia, Fluid Retention, Orthostatic HPN (first dose syncope)
Sympatholytic: Beta-adrenoceptor Antagonist
MOA: Blocks B1-receptors
Selective: Metoprolol, Atenolol
Non-Selective: Propranolol, Nadolol, Labetalol, Carvedilol
Use: Reduce HR, Contractility, renin secretion
Sympatholytic: Centrally-Acting Drugs
(+) Alpha-2 Agonists
- Clonidine (Catapres)
- Guanfacine
- Guanabenz
- Methyldopa (Aldomet®, Dopamet®) - converted first to ⍺-methyldopamine & ⍺-methylNE
Calcium Channel Blockers
i. Dihydropyridines (DHPs) - Vasoselective
* Nifedipine (Adalat®)
* Nimodipine (Nicardia®)
* Amlodipine (Norvasc®)
* Felodipine
ii. Non-DHPs - Antiangina, Antiarrhythmia
* Verapamil
* Diltiazem
MOA of Dihydropiridine CCBs
Block the L-type Ca channel in arteriolar smooth muscles
MOA of Non-DHP CCBs
Block the L-type Ca channel in arteriolar smooth muscles and myocardium
DOC for Subarachnoid hemorrhage
Nimodipine
A/Es of Dihydropiridines
Flushing
Gingival Hyperplasia
Reflex tachycardia
Peripheral edema
Cardioselective; greatest depressant effect in the heart amongst all CCBs
Verapamil
S/E: Constipation
DOC for Prinzmetal Angina
Verapamil + Trandolapril
Vasodilators
a. Arteriolar Vasodilators
* Hydralazine
* Minoxidil
* Diazoxide
b. Mixed Arteriolar/Venous dilators
* Na Nitroprusside
* Fenoldepam
Hydralazine MOA
Increases levels of Nitric
Oxide (endogenous vasodilator)
↑ NO ↑ cGMP. NO interacts with guanylate cyclase. GTP is thus converted
Hydralazine
Uses:
* Management of HTN specifically in pregnant wpmen with HTN crisis
* Adjunct in the management of CHF (with ISDN)
SE: Systemic Lupus Erythematous
Minoxidil
MOA: induce opening of K+ channel in the vascular/arteriol smooth muscles
Use: most efficacious but alternative only for HTN crisis
SE: Hirsutism, hypertrichosis
Diazoxide
MOA: same with minoxidil
Use: alternative for hypertensive crisis, Treatment of Insulinoma
SE: HyperGLU (metabolic related)
Common A/Es of Vasodilators
- All arteriolar vasodilators cause reflex
tachycardia - Peripheral edema
Na Nitroprusside
MOA: increase CGMP levels (Releases NO from drug molecule)
First line in hypertensive emergency
Na Nitroprusside
Special precautions: Na nitroprusside
Na nitroprusside must be freshly prepared, used within 24 hrs; prone to photodegradation
Adverse Effects of Na Nitroprusside
Cyanide Toxicity
Accumulation of cyanide (inhibits cytochrome oxidase =
cellular respiration is inhibited)
Management of Cyanide Toxicity
Cyanide Antidote Kit
* amyl nitrate!
* Na nitrite (NaNO2)
* Na thiosulfate (Na2S2O4)
Hydroxo / Hydroxycobalamin
Methylene blue (high dose)
Fenoldepam
Activates Dopamine 1 → Vasodilation
Base treatment in px with CHF, HPN + Diabetic nephropathy
ACE Inhibitors (-pril)
1st line in the management of HTN in px with CKD or
DM; 1st line in the management of Albuminuria
ACEIs & ARBs
MOA of Angiotensin Converting Enzyme
Inhibitors (ACEIs)
Prevent formation of Angiotensin II
Dec. vasoconstriction, Inc. bradykinin, increase prostaglandin
Decrease AII, BV, SVR
Inc. bradykinin, decreasing SVR
Angiotensin Converting Enzyme
Inhibitors (ACEIs)
Captopril
Fosinopril
Ramipril
Enalapril
Angiotensin Converting Enzyme
Inhibitors (ACEIs)
Captopril - sulfhydryl group
Fosinopril
Ramipril
Enalapril
all -prils are prodrugs except: Acute ACEi where their parent molecules are already activates
- Capropril
- Lisinopril
- Enalaprilat (IV)
Adverse Effects of ACEIs
Hyperkalemia
Fetal Injury
Dry cough (Inc. bradykinin)
* NSAIDS - reduce the efficacy of ACEi in the mx HTN
Angiotensin Receptor Blockers (ARBs: -sartan)
Losartan
Candesartan
Valsartan
Saralasin
MOA of Angiotensin Receptor Blockers
(ARBs)
Prevents the action of AT1
Blocks the binding of AT1 to its receptor
A/Es of Angiotensin Receptor Blockers
(ARBs)
Hyperkalemia
Fetal Injury
NO Dry cough
Renin Inhibitor
Aliskerin
Aliskerin
MOA: Renin inhibitor; reduces angiotensin I synthesis /(binds to rennin preventing interaction of rennin to angiotensin
CLINICAL USE/S: add-on to ACE-inhibitors or ARBs for HTN
SE: Angioedema, renal impairment, dry cough, rashes