antihypertensives Flashcards
what are the first line antihypertensives?
- ACE inhibitors
- lisinopril, captorpil, enalapril - Angiotensin II Type 1 Blockers
- valsartan, losartan, smth ‘sartan’ - Beta adrenoreceptor Antagonists
- [non-selective] propanolol, pindolol, carvedilol
- [beta-1 selective] atenolol, bisoprolol, metoprolol
- [mixed - 3rd gen] nebivolol - Calcium channel blockers
- dihydropyridines (nifedipine, amlodipine)
- non-DHP (verapamil, diltiazem) - Diuretics
- thiazide
What are the second line antihypertensives?
- Alpha adrenoreceptor Antagonists
- prazosin, smth “zosin” - Hydralazine
- Mineralocorticoid Receptor Blockers
- spironolactone, smth ‘one’
What is the MOA of ACE inhibitors?
- inhibits ACE
- prevents Angiotensin I from converting to Angiotensin II
- decrease in angiotensin II
- decrease vasoconstriction -> decrease peripheral resistance
- decrease aldosterone -> decrease Na+/H2O retention
=> lowers BP - reduce bradykinin inactivation
- bradykinin increases and starts to accumulate
- increases NO, PG
- increases vasodilation
=> lowers BP
Contradictions using ACE Inhibitors (“pril”)?
Pregnancy
What is the MOA of Angiotensin II Type 1 blockers (“sartan”)?
- blocks AT1 receptor -> blocks angiotensin II
Contraindications using Angiotensin II Type 1 blockers (“sartan”)
Prenancy
What beta adrenoreceptor blockers are also heart failure meds?
Carvedilol, Bisoprolol, Metoprolol, Nebivolol
MOA of beta adrenoreceptor antagonists (“olol”)
- blocks B1 adrenoreceptor on cardiac myocytes
- decrease adenylate cyclase
- decrease ATP conversion to cAMP
- decrease PKA activation
- decrease opening of Ca2+ channels
- decrease influx of Ca2+ into cardiac myocytes
- decrease cytosolic Ca2+
- decrease calcium induced calcium release
- decrease activation of sarcoplasmic reticulum calcium
- decrease calmodulin activation
- decrease activation of actin-myosin complex
- decrease contractility of cardiac myocytes
MOA of calcium channel blocker
- blocks calcium channels
- decrease influx of Ca2+
- decrease cytosolic Ca2+
- decrease calcium induced calcium release
- decrease activation of sarcoplasmic reticulum calcium
- decrease calmodulin activation
- decrease activation of actin-myosin complex
- decrease contractility of cardiac myocytes
Effects of calcium channel blocker
- decrease SA and AV nodes -> decrease supra ventricular reentry tachycardia (non-DHP)
- decrease contractility of cardiac myocytes -> decrease O2 demand & CO (DHP)
- decrease vascular smooth muscle tone -> decrease BP (DHP)
What calcium channel blockers are preferred for lowering BP?
verapamil = diltiazem = nifedipine
What calcium channel blockers are preferred as vasodilator?
nifedipine > diltiazem > verapamil
What calcium channel blockers are preferred as cardiac depressant?
verapamil > diltiazem > nifedipine
What are NON-DHP
verapamil, diltiazem
- anti-arrhythmic
higher affinity to Ca channels on smooth muscles /electrical conduct of the heart
- blocks SA and AV nodal conduction
MOA of diuretics (thiazides)
- Ca2+ is reabsorbed at the distal convoluted tubule epithelial cell via apical Ca2+ channels and basolateral Na+/Ca2+ exchanger
- Thiazides will block Na+/Cl- transporter, inhibiting Na+ reabsorption
- concentration of Na+ in the tubular cells will decrease, increasing the activity of Na+/Ca2+ exchanger, driving the reabsorption of Ca2+ through the Ca2+ epithelial channels
- increased Ca2+ reabsorption -> decrease hypercalciuria