PPT Flashcards
Outline the stepwise approach to drug treatment of hypertension?
<55 and not African or Caribbean origin
1: ACE or ARB
2: add CBB
3: add thiazide-like diuretic
4: spironolactone
> 55 or African or Caribbean origin
1: CCB
2: add ARB (or ACEi)
3: add thiazide-like diuretic
4: spironolactone
How long should you leave Antihypertensive drug therapy to check for therapeutic effect?
Allow 1 month before emulating therapeutic effect
!!! Unless treating hypertensive crisis!
Whats the blood pressure level aims when on Antihypertensive drug therapy?
If <80
<140/90mmHg in clinic
<135/85mmHg (home bp measurement)
If >80
<150/90 in clinic
<145/85 at home
Why should you not use ACEi and ARBs together?
Particular risk of hyperkalaemia
What proportion of pt on ACEi will get a dry cough?
~10%
Why dont ARBs cause a dry cough like ACEi?
ACE inhibitors cause cough by increasing bradykinin levels
ARBs have minimal effect on bradykinin
What are the important cautions of ACEi?
First dose hypotension - take first dose before bed because of this
Agranulocytosis - very rare
Anaphylactoid reactions - also very rare
Risk of hyperkalaemia if taken with diabetes however these drugs are still given despite this
What are contraindications of ACEi?
Angioedema (hereditary or idiopathic)
Taking with aliskiren with eGFR or diabetes
Pregnancy and breast feeding
Aortic stenosis
Hyperkalaemia >= 5.0mmol/L
Renovascular disease
What do ACEi interact with?
Aliskiren (direct renin inhibitor) - significant increased risk of renal impairment and hyperkalaemia
Allopurinol - higher risk of hypersensitivity and haematological reactions e.g. Stevens-Johnson syndrome
Azathioprine - increased risk of anaemia and leukopenia
Everolimus (a protein kinase inhibitor for neuroendocrine tumours of GIT/pancreas) - increased risk of angioedema
Lithium (ACEi increase its concentration and increase risk of toxicity)
High-dose diuretic therapy e.g. >80mg furosemide - significantly increases risk of hypotension
What is Stevens-Johnson syndrome?
a severe systemic reaction affecting the skin and mucosa that is almost always caused by a drug reaction
What drugs cause Stevens-Johnson syndrome?
penicillin
sulphonamides
lamotrigine, carbamazepine, phenytoin
allopurinol
NSAIDs
oral contraceptive pill
What are features of Stevens-Johnson syndrome?
Maculopapular rash with target lesions that may develop into vesicles or Bullae
Mucosal involvement
Systemic symptoms - fever, arthralgia
What are the common + important SE of ACEi?
Dry cough
Dizziness
Headaches
Diarrhoea and vomiting
Blurry vision
Angioedema
Hyperkalaemia
First dose hypotension
Rare but important - agranulocytosis, liver dysfunction, kidney disease
Who is most likely to experience first-dose hypotension when taking ACEi?
Pt taking diuretics
What are the sick day rules for ACEi?
Consider temporarily stopping if experiencing D+V as the dehydration can increase the risk of AKI and enhance the drug effects - may experience more dizziness/falls etc
What monitoring is done for ACEi?
U&Es should be checked before treatment is initiated and after increasing the dose
How much of an effect can lifestyle changes have on cholesterol levels?
It can only really reduce cholesterol by 10% compared to statins which can have an effect of up to 50% reduction!
Whats the moa of ACEi?
inhibit the conversion angiotensin I to angiotensin II. Decreased production of angiotensin II means less coronary blood vessel constriction which reduces vascular resistance and vascular smooth muscle cell proliferation
Increased levels of bradykinin also causes vasodilation g effects
When should you treat stage 1 hypertension?
treat if < 80 years of age AND any of the following apply; target organ damage, established cardiovascular disease, renal disease, diabetes or a 10-year cardiovascular risk equivalent to 10% or greater
Suggestion… consider antihypertensive drug treatment in addition to lifestyle advice for adults aged under 60 with stage 1 hypertension and an estimated 10-year risk below 10%.
Which CCB are used for treating hypertension?
Verapamil
Diltiazem
Nifedipine
Amlodipine
Felodipine
Why should verapamil not be given with beta blockers?
It can cause heart block
Whats the MOA of calcium-channel blockers?
They interfere with the inward displacement of Ca2+ though the slow channels of the active cell membranes which influences the myocardial cells anc cells of vascular smooth muscle
Thus, myocardial contractility may be reduced, the formation/propagation of electrical impulses within the heart may be depressed, and coronary or systemic vascular tone may be diminished
What are cautions for CCB?
Elderly - STOPP criteria
Known hypersensitivity - contraindication
Heart failure - except amlodipine
Cautions in cardiac outflow obstruction, diabetes, AV block, unstable angina or MI within 1 month
Cautions with hepatic and renal impairment
Pregnancy and breastfeeding - avoid
What are SE for CCB?
Abdominal pain
Dizziness and drowsiness
Flushing
Headache
Nausea and vomiting
Palpitations
Peripheral enema
Skin reactions
Tachycardia
Whats the MOA of statins?
They inhibit HMG CoA reductase which reduces intracellular cholesterol levels - this activates a protease which causes upregulation of expression of the LDL receptor gene = increased receptor-mediated endocytosis of LDL = reduces serum LDL
Why is it suggested that Simvastatin is taken at night?
Because of the diurnal variation of HMG-CoA reductase
The enzyme is more active at nigh so more LDL is synthesised at night
Simvastatin has a much shorter half life than atorvastatin so its best taken at night
What metabolises statins?
CYP3A4 in the liver
What are the SE of statins?
Myopathy
Liver impairment
GI discomfort
Headache
Sleep disorders
Thrombocytopenia
What can interact with statins?
CYP3A4 inhibitors:
Grapefruit juice
HIV protease inhibitors
Macrolide antibiotics
Azole antifungal
CCB - diltiazem and verapamil
CYP3A4 inducers:
St John’s wort
Glucocorticoids
Antiepielptics
Rifampicin
What are monitoring requirements for statins?
Before starting - full lipid profile, TSH, renal function, CK, LFTs
LFTs- repeat at 3 and 12 months (stop if serum transaminases raised >3 times upper limit of reference range)
HbA1c if at risk of diabetes mellitus and repeat after 3 months
Whats the moa of fibrates?
Agonist of PPAR-alpha
They decrease triglyceride levels and increase HDL
Who are fibrates contraindicated in?
Gallbladder disease
Hypoalbuminaemia
Nephrotic syndrome
Severe hepatic impairment
Pregnancy and breast feeding
Hypersensitivity
Caution with renal impairment as may increase Cr, and may interact significantly with anticoagulants therapy
What monitoring should be done for fibrates?
Monitor LFTs
Before starting check TFTs and if hypothyroidism correct this first
Monitor CK if using alongside statins
What are the SE of fibrates?
Tend to be mild - GI disturbances and headache
Pruritus and rashes have also been reproyted
Whats the moa of ezetimibe?
Inhibits intestinal absorption of cholesterol
What are SE of ezetimibe?
GI discomfort and fatigue
Myopathy particularly if used alongside statins/niacin, can damage pancreas and liver
Allergic reactions
Whats the moa of bile acid sequestrants?
Binds to bile acids and prevents their reabsorption = promotes hepatic conversion of cholesterol into bile acids = increased LDL receptor activity = increased clearance of LDL from plasma
Who are bile acid sequestrants contraindicated in?
Complete biliary obstruction - not likely to be effective
What are SE of bile acid sequestrants?
GI upset and headache
May interfere with absorption of fat-soluble vitamine - ADEK and folic acid
What are examples of bile acid sequestrants?
colestyramine, colestipol, colesevelam.
Whats the thiazide-like diuretic suggested by NICE?
Indapamide
What are contraindications for thiazide-like diuretics?
Refractory hypokalaemia.
Hyponatraemia.
Hypercalcaemia.
Addison’s disease.
Symptomatic hyperuricaemia.
Severe liver disease.
Severe renal impairment
Pregnant women
What are adverse effects of thiazide-type diuretics?
dehydration
postural hypotension
hyponatraemia, hypokalaemia, hypercalcaemia*
gout
impaired glucose tolerance
impotence
Rare- thrombocytopenia, agranulocytosis, photosensitivity rash, pancreatitis
What are side efefcts of beta blockers?
bronchospasm
cold peripheries
fatigue
sleep disturbances, including nightmares
erectile dysfunction