W1, 4 Antihypertensive Drugs Flashcards
β¦β¦β¦β¦β¦.. is the term for high blood pressure with
unknown cause. It accounts for about 95% of cases.
Essential hypertension
β¦β¦β¦β¦ is the term for high blood pressure with
a known direct cause, such as kidney disease, tumors or drug-induced.
Secondary hypertension
Chronic elevated blood pressure increases risk of damage to β¦. (What organs)?
kidneys, heart and brain.
Complete the table:
Non-drug Treatment (Life style modifications)
Anti-hypertensive agents are used to:
(how do they act?)
- To antagonize the actions of factors that increase blood pressure.
- To potentiate the actions of factors that decrease blood pressure
Classes of Antihypertensive Drugs
What drugs are classified under Diuretics?
(Only the Highlighted is on the drug list)
guidelines of American Heart Association to treat HTN
First-line drug for hypertension
diuretics
Route of administration of diuretics?
Given orally, alone or combined with other anti-hypertensives.
Mechanism of action of diuretics?
Most diuretics act by interfering with sodium reabsorption
resulting in sodium and water excretion (diuresis).
Side effect of both diuretics loop & thiazide?
Thiazide and loop diuretics an cause depletion of K+, leading to hypokalemia.
β¦β¦β¦ are one of the preferred initial mono- therapies for HTN.
Thiazide diuretics
Side effects of Thiazide Diuretics
- hypokalemia
- hyperglycemia
What type of diuretics is more potent &is called high ceiling diuretic ( have maximum secretion)
Loop diuretics (Furosemide)
Side effects of loop diuretics
- hypokalemia
- ototoxicity (hearing loss)
What causes the release of renin?
Activation of Ξ²1 in the kidneys will cause the release of renin
Whatβs the action of renin?
Converts Angiotensinogen to Angiotensin 1
How is Angiotensin 1 converted to Angiotensin 2?
By ACE (Angiotensin converting enzyme)
The Renin-Angiotensin System (Slide)
Give example of Renin Inhibitor
Aliskiren
Mechanism of action of Aliskiren (selective or not + how does it lower BP)?
Aliskiren a selective renin inhibitor. Acts earlier in RAS than ACE inhibitors or ARBs.
# Works by relaxing blood vessels, which lowers blood pressure.
ACE inhibitors example
Captopril (Blocks the conversion of angiotensin I to angiotensin II)
Mechanism of action of ACEIs
What drug prevent the loss of kidney function associated with diabetic nephropathy?
Captopril (ACEI)
Side effects of ACEI?
Dry cough is the most common side effect of ACEI therapy
(cough due to increase bradykinin)
Angiotensin II Receptor Blockers (ARBs) example
Losartan
What is more effective ACEI or ARBS and why?
Mechanism of action of ARBs
Commonly side effects of ARBs
Hypotension, Orthostatic hypotension, Weakness, fatigue, diarrhea
Dosage & route of administration of ARBs
- Initial dose: 50 mg orally once a day.
- Maintenance dose: 25 to 100 mg orally in 1 to 2 divided doses.
Calcium Channel Blockers (CCB) drug examples
What CCB are smooth muscle selective?
Dihydropyridines: Nifedipine, Amlodipine
What CCB are smooth cardio-selective?
Non-dihydropyridines: Verapamil
What CCB acts on Both vascular smooth muscles & myocardial cells?
Diltiazem (intermediate)
What drugs cause Vasodilator effect in the arteries, decrease peripheral resistance and lower blood pressure.
Dihydropyridines: Nifedipine, Amlodipine
What drugs do the following:
# Decrease AV and SA nodal conduction.
# Lower blood pressure.
Non-dihydropyridines (e.g. Verapamil acts on the heart)
Side Effects of Calcium Channel Blocker
- Include headache or constipation.
- Non-dihydropyridines can decrease heart rate, cause heart failure.
What CCB is intermediate in specificity.
Diltiazem
Beta Adrenoceptor Blocking Agents drug examples
- Non-selective: Propranolol
- Beta-1 selective: Atenolol
How do beta-blockers work?
Lower blood pressure by decreasing cardiac output & inhibiting the release of renin.
(as we said earlier We have Ξ²1 receptors on the heart & kidneys β> so if we Block Ξ²1 receptors:
* on the heart -> reduce cardiac output
* on kidneys -> inhibit renin -> reduce RAAS
Beta adrenoceptor blockers (slide)
Side effects of beta blockers
Antagonism of Beta-2 adrenergic receptors may lead to bronchospasm.
What type of beta blockers is given for asthmatic patients?
- you need to give selective Ξ²1 antagonist if the patient is asthmatic
(Bcz if you use a Non-selective Ξ² blocker you will block Ξ²1 in the heart and help the patient reduce BP But you will also block Ξ²2 in bronchioles and cause bronchoconstriction so you will increase the problem if the patient has asthma)
What drugs are Alpha-1 Adrenoceptor Blocking Agents?
Doxazosin, Prazosin
Alpha-1 Adrenoceptor Blocking Agents actions?
- Block alpha1-adrenergic receptors on vascular smooth muscle.
- Vasoconstriction is reduced, and peripheral vasodilation occurs.
Uses a1 receptor blockers
- For treatment of high blood pressure, also improve urine flow, reduce urinary symptoms associated with prostate enlargement.
- Beneficial for treatment of prostate gland enlargement, benign prostatic hyperplasia (BPH). Enlarged prostate can cause problems with passing urine. (Relax the muscles around the bladder and prostate, improve urinary flow.)
Side Effects of a1 receptor blockers
Most common side-effects include drowsiness, headaches and dizziness.
Alpha-1/Beta-adrenoceptor Blocking Agents drugs examples?
Carvedilol (combined nonselective antagonism at alpha-1 and beta adrenergic receptors)
Contraindications of Alpha-1/Beta-adrenoceptor Blocking Agents (Carvedilol)
- Bronchial asthma (bcz Ξ² blockers might exaggerate bronchoconstriction)
- Severe bradycardia (Bcz blocking Ξ²1 receptors will reduce heart rate)
Alpha-2 Adrenergic Agonists (Centrally acting) drug examples?
Alpha-Methyldopa, Clonidine
MOA of Alpha-2 Adrenergic Agonists?
- They stimulate presynaptic alpha-2 receptors on adrenergic neurons within the medulla, which controls sympathetic outflow.
- This prevents the release of noradrenaline and subsequent postsynaptic alpha-1 receptor activation.
β¦.. is used to treat pregnancy-induced hypertension?
Methyldopa
Direct Vasodilators drug examples
Hydralazine, Minoxidil
MOA of Direct Vasodilators
They act directly on the vascular smooth muscle cell to cause relaxation mostly in arteries and arterioles. (Result in decreased peripheral resistance and blood pressure.)
Side effects of Direct Vasodilators
headache, swelling in the lower legs.
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FIRST LINE THERAPY FOR COMPELLING INDICATIONS
Table (slide)
