Antihypertensive Drugs Flashcards
What drugs can induce hypertension
Nasal decongestant
NSAIDs
How do drugs that aim to reduce BP generally work
They aim to reduce TPR or cardiac output
BP=TPRxCO
What are the first line antihypertensive drugs
ACE I and ARBS
Beta blockers
Calcium channel blockers
Diuretics - thiazides
What’s first line diuretics for antihypertensive
Thiazides - hydrochlorothiazide, indapamide and chlorthalidone
Thiazides mechanism of action
Inhibition of Na+ - Cl- symporter in the distal convoluted tubule leading to
Increased secretion of —>Na,K and water
Thiazides adverse effects
Hypokalemia, hypercalcemia, hyperuricemia(gout), hyper lipidimia Hyponatremia Hypovolemia Hyperglycaemia
What are the second line diuretics for antihypertensive drugs
Loop diuretics Furosemide Torsemide Bumetanide Ethacrync acid
Loop diuretics mechanism of action
Block Na+/K+/Cl- transporter in the thick ascending limb of loop of henle
Loop diuretics side effects
Hypokalemia
Hypocalcemia
Hypomagnesemia
Ototoxicity
ACE I suffix
-pril
ACE I mechanism of action
Block conversion of ang 1 to ang2 —> decreasing TPR and aldos
Which RAAs are not prodrugs
Captopril and lisinopril
What does ACE I cause leading to side effects
Increases level of bradykinin levels (dry cough and angioedema and increased PGE -> vasodilation
What are ACE I first line for and why
ACE I inhibit progression of kidney changes hence they are 1st line drugs in patients with HTN and diabetes mellitus
ACE I contraindications
Pregnancy
History of angioedema
Presistant cough
Bilateral renal artery stenosis
List AT blockers
-sartan
Losartan
Valsartan
When are ARBs given instead of ACE I
- Given to patients with ways of Ang 2 formation (angiotensin escape)
- Can’t tolerate ACE-I side effects
What effect does losartan have on uric acid
Increase excretion of uric acid and decrease blood levels
The the case of
Hypertension + increased CV risk /metabolic complications
Which is preferred ACE I vs ARBs
ACE I > AT blockers / ARBs
In the case of
Uncomplicated hypertension + decreased CV risk
Which is preferred ACE I vs ARBs
ACE I = AT blockers
Can AT blockers be given to pregnant women
No they are teratogenic
Aliskiren mechanism of action
Direct inhibition of renin -> preventing conversion of angiotensinogen to Ang1
Can aliskiren be given to pregnant women
No it’s Teratogenic
What are the types of calcium channel blockers
Dihydropyridine and non dihydropyridine
List the Dihydropyridine CCB
Nifedipine and amlodipine
Dihydropyridine mechanism of action
Blocks Ca2+ channels on blood vessels only causing vasodilation
List non Dihydropyridines
Diltiazem and verapamil
Non dihydropyridine mechanism of action
Blocks Ca2+ channels on blood vessels and heart
Adverse effects of dihydropyridines
Can cause Peripheral artery disease
Causes peripheral edema
Treatment ACE I or ARBS
Non dihydropyridine side effects
Constipation
Which drugs that alter the CNS are used in hypertension
Non selective a antagonists
a1 antagonists
B blockers
Centrally acting agents
List non selective a-antagonists used in hypertension
Phentolamine- reversible
Phenoxybenzamine- irreversible
Non selective a-antagonists indication
Pheochromacytoma
List a1 antagonists used in hypertension
Doxazosin and terazosin
a1 antagonists mechanism of action
Inhibits a1 on blood vessels leading to vaso dilation and decrease in TPR
Also increases HDL and decreases LDL and beneficial in insulin resistance
a1 antagonists Adevrse effects
Orthostatic hypotension, nasal congestion and heart failure
B-blockers mechanism of action
- Decrease CO - inotropic and - chronotropic
- reduction in renin release from kidneys
- vasodilation (only third generation)
List centrally acting agents
Clonidine and methyldopa
Centrally acting agents mechanism of action
Central a2 receptors agonists
Which centrally acting agent is safe in HYN in pregnancy
Methyldopa
Centrally acting agents adverse effects
Rebound HTN if discontinued abruptly and that leads to hypertensive crisis
List the direct vasodilators
Hydralazine and minoxidil
Direct vasodilators mechanism of action
Decrease TPR by relaxing arterioles but can lead to reflex tachycardia and fluid retention
Hydralazine mechanism of action
Inhibits release of Ca2+ from sarcoplasmic reticulum in arterial smooth muscles
Hydralazine side effects
SLE and reflex tachycardia
Minoxidil mechanism of action
Opening of K+ channels in smooth muscle membranes
Minoxidil side effects
Hypertrichosis (increase hair growth) can be used in bald people
What is the initial therapy drug strategy
Low dose dual therapy
ACE-I or ARB + CCB or Diuretic
Why is low dose dual therapy better than highdose monotherapy
Because all adverse effects are dose dependant except in ACE-I
What triple therapy drug strategy
ACEi or ARB + CCB + Diuretic
When are B-blockers added to therapy?
Can be added at any step when indicated heart failure, angina l, post MI and fibrillation
Medications used for hypertension in pregnancy
Methyldopa, labetolol and nifedipine
