Anti-HTN drugs Fatema Pinky MAM Flashcards
(46 cards)
What is hypertension?
Sustained raise of blood pressure ≥ 140/90 mmHg
What is pre-hypertension?
120-139/80-89 mmHg
What defines Stage 1 Hypertension?
140-159/90-99 mmHg
What defines Stage 2 Hypertension?
> 160/100 mmHg
What are the causes of hypertension?
Primary / essential / idiopathic; Secondary: Renal diseases, endocrine diseases, metabolic syndrome, drugs
What are the determinants of blood pressure?
Cardiac output * peripheral vascular resistance
BP= CO*PVR
What is the formula for blood pressure?
BP = CO x PVR
What factors affect cardiac output?
- Heart rate
- Stroke volume
What lifestyle changes can help lower high blood pressure?
- Eating a healthy, low-salt diet
- Losing weight
- Being physically active
- Quitting tobacco
What are the two main therapeutic approaches to hypertension?
- Decrease of PVR
- Decrease of CO
Name an anatomical site of action of antihypertensive drugs.
- Heart
- Kidneys
- Sympathetic nervous system
- Renin-angiotensin-aldosterone axis
- Vascular smooth muscle
What are the classes of antihypertensive drugs?
- Diuretics
- ACE inhibitors
- Angiotensin receptor blockers
- Calcium channel blockers
- Sympatholytics
- Vasodilators
- Renin inhibitors
What is the antihypertensive action of alpha-methyl dopa?
Acts as a pre-synaptic α2 agonist, inhibits release of NA from presynaptic neurons
What are the kinetic properties of alpha-methyl dopa?
Prodrug, 25% bioavailability, maximum action within 4-6 hours, duration of action 12-24 hours
List adverse effects of methyl dopa.
- Sedation
- Depression
- Increased prolactin secretion
- Rarely diarrhea and hepatitis
- Coombs positive hemolytic anemia
What is the mechanism of action of clonidine?
Directly stimulates non-neuronal α2 in arterioles, inhibits release of NA from presynaptic neurons
List uses of clonidine.
- Moderate hypertension
- Prophylaxis of migraine
- Postmenopausal syndromes
- Withdrawal symptoms of addictive drugs
- Attention deficit in hyperactive children
What are ganglion blockers?
Competitively block N receptor on post-ganglionic neurons, causing sympathoplegic effects
What are the adverse effects of ganglion blockers?
- Orthostatic hypotension
- Sexual disturbances
- Antimuscarinic effects (dry mouth, blurred vision)
What is the role of reserpine as an antihypertensive agent?
Blocks storage/release of noradrenaline from sympathetic neurons
What are the adverse effects of reserpine?
- Sedation
- Severe mental depression
- Extrapyramidal side effects
- Abdominal cramps
- Hyperacidity
List the alpha adrenergic blockers.
- Prazosin
- Terazosin
- Phenoxybenzamine
- Phentolamine
- Tolazoline
What is the antihypertensive action of prazosin?
Competitively blocks α1, dilates resistance and capacitance vessels, decreases PVR
List adverse effects of alpha adrenergic receptor blockers.
- Postural hypotension
- Palpitations
- Dizziness
- Headaches
- Syncope