Pharmacology Flashcards
name some examples of ACEi
- ramipril
- lisinopril
- captopril
look for “pril” ending
describe the mechanism of action ACEi
- angiotensin converting enzyme (ACE) is found in the pulmonary circulation and endothelium of blood vessels
- ACE converts angiotensin I to angiotensin II, thereby increasing the blood pressure
- ACEi block this conversion and reduces blood pressure
reduces the activity of the renin-angiotensin-aldosterone system (RAAS)
describe the effects fo angiotensin II
increase blood pressure
* vasoconstriction
* vascular smooth muscle hypertrophy
* ventricular remodelling
* hypertrophy
* aldosterone and vasopressin release
what are the indications for an ACEi?
- hypertension
- angina
- post-MI
- symptomatic heart failure
- diabetic nephropathy
- prevention of cardiovascular events
describe ACEi side-effects
CAPTOPRIL
* Cough - caused by an increase in bradykinin levels
* Angio-oedema
* Proteinuria
* Taste disturbance/teratogenic in 1st trimester
* Other (fatigue, headache)
* Potassium increased
* Renal impairment
* Itch
* Low BP (1st dose)
what are the contra-indications to ACEi use?
- pregnancy and breast feeding
- aortic stenosis
- renovascular disease
- idiopathic angioedema
what U&Es need to be monitored while on ACEi?
- creatinine - increase of 30% = acceptable
- potassium - increased to 5.5mmol/L = acceptable
name some thiazide-like diuretics
mineralocorticoid antagonists
- spironolactone
- eplerenone
describe the mechanism of action of thiazide-like diuretics
mineralocorticoid antagonists
- mineralocorticoids are synthesized in the adrenal glands
- bind to mineralocorticoid receptors in the cells in the renal tubule
- leads to increased sodium reabsorption and potassium excretion in the distal tubule and collecting duct
- via the formation of more Na-K-ATPase pumps and epithelial sodium channels (ENaC)
- thiazide-like diuretics block this mechanism
- leads to potassium reabsorption and sodium excretion
- this results in water excretion which decreases blood pressure
what are the indications for thiazide-like diuretics?
- ascites in liver cirrhosis
- congestive heart failure
- nephrotic syndrome
- resistant hypertension
- primary hyperaldosteronism
what are the side-effects of thiazide-like diuretics?
- increased urination
- nausea and vomiting
- stomach cramps
- hyperkalaemia
- diarrhoea
- gynaecomastia
what are the contra-indicatiosn to thiazide-like diuretics?
- addison’s disease
- anuria
- hyperkalaemia
what classic of medication is isoprenaline?
selective beta-adrenoceptor agonist
describe the mechanism of action of isoprenaline
- stimulation of b1-adrenoceptors leads to positive inotropic and chronotropic effects
- leads to an increase in cardiac force and rate
- stimulation of b2-adrenoceptors leads to vasodilatation
- reduces peripheral resistance and blood pressure
- mean arterial pressure falls
- this hypotension leads to reflex tachycardia due to the baroreceptor reflex
describe the mechanisms of action of digoxin
- inhibits the Na/K ATPase ion pump in the myocardium
- also has parasympathetic effects on the AV node
- negatively chronotropic and positively ionotropic
- slows heart rate but increases contractility
what effects does digoxin have on an ECG?
- downslopping ST depression
- T-wave changes (inversion)
- biphasic/flattened and shortened QT interval
- slight PR interval prolongation
- prominent U-waves
morphology of the QRS complex/ST segment = slurred/sagging and resembling a reverse tick
what are the features of digoxin toxicity?
- nausea/vomiting
- diarrhoea
- blurred vision
- yellow/green discolouration of vision
- haloes in vision
- confusion
- fatigue
- palpitations
- syncope
name some examples of statins
- simvastatin
- atorvastatin
- pravastatin
describe the mechanism of action of statins
- statins inhibit the action of hydroxy beta-methylglutaryl-CoA (HMG-CoA) reductase which is the rate-limiting enzyme in hepatic cholesterol synthesis
- means less cholesterol is produced by the liver so the levels in the blood will decrease
what time of day should statins be taken?
at night - because this is when most cholesterol synthesis takes place
what are the indications for statins?
primary prevention
* anyone with a 10-year cardiovascular risk (Qrisk) >= 10%
* type 1 diabetes mellituse diagnosed for >10 years or aged >40 years or with concurrent nephropathy
secondary prevention
* stoke/TIA
* ischaemic heart diseae
* peripheral arterial disease
what are the side-effects of statins?
- myalgia
- myositis
- rhabdomyolysis
- hepatic impairment
what are the contra-indications to statins?
- macrolides (erythromycin, clarithromycin)
- pregnancy
what is the most serious acute side-effect in statins?
myositis in the form of rhabdomyolysis
