Antihypertensive Drugs Flashcards
What can hypertension cause?
Stroke
Ischaemic heart disease and peripheral vascular disease
What is the equation for blood pressure?
Blood pressure = cardic output x total peripheral resistance
What would be the initial treatment for someone suffering from hypertension?
Cut salt and alcohol Reduce weight Exercise Stop smoking Eat healthy
What controls blood pressure?
Baro receptors
> to medulla > to San and articles when then add or decrease blood flow.
WhT are the targets for hypertension drugs?
Kidney
Heart
Blood vessels
Brain
Explain the renin - angiotensin system?
Low blood pressure - leads to kidney releasing renin - converts to angiotensinogen - to angiotensin 1 - Ace enzyme converts angiotensinogen 2 - causes vaso constriction which then increases blood pressure
Ace inhibitors
action
examples
side effects
Action -blocks ace enzyme which causes vaso desolation which reduces peripheral resistance
Example -first line of therapy would be captopril, enalapril, lisinopril.
Side effects - persistent dry cough, rash, renal problems, hypotension not for pregnancy
What is an alternative to ace inhibitors?
Angiotensinogen receptor antagonists these block receptors that ang2 binds to which causes vaso dililation no cough, cause dizziness and hyper kalaemia.
Beta blockers
Action
Side effects
Action - block beta1 receptors so reduce heart rate, reduce sympathetic mediated vaso constriction, it increases blood flow to kidneys and decreases renin secretion
Examples atenolol propranolol
Side effects - lethargy, impaired concentration, aching limbs , erectile dysfunction, aggravation of asthma .
Explain A blockers and their side effects?
Blocks action of nadr and adrenalin on blood vesicles which leads to vaso dialation. Eg prazosin
Explain the mechanism of calcium Chanel blockers and give examples?
Increases myocardial contractability which cause increased heart rate and av node conduction and vaso constriction
Eg nifedipine, and amlodipine- more potent on bv than heart - headache flushing dizziness and oedema
Eg verapamil and diltiazem - more potent on heart than bv - constipation, cardiac failure
What do some calcium blockers interact with?
Grapefruit juice
How does diretics produce a decrease in blood pressure
Example
Side effects
The increase urine input which decreases blood volume which decreases blood pressure
Eg indapamide
Side effects decrease ka , decrease insulin release, increased plasma lipids, leads to gout and erectile dysfunction
What are the causes of hypertension?
Genetic Low birth weight Environmental Diabetes Drugs Kidney/ cardio vascular disease
