ELM 6.2 Flashcards
Indications
what the drug should be used for
cautions
conditions or factors that increase the risk of the drug
contra-indications
conditions or factors that suggest a drug should not be prescribed
side effects
unwanted effects of a drug
Propranolol causes bradycardia (slowing of the heart rate) via:
a. agonist actions at β1 adrenoceptors
b. antagonist actions at β1 adrenoceptors
c. agonist actions at β2 adrenoceptors
d. antagonist actions at β2 adrenoceptors
b
Although propranolol is relatively unselective between β1 and β2 adrenoceptors, its actions on heart rate occur via β1 receptors.
bronchiospasm
heart failure
metabolic acidosis
raynaud’s phenomenon
Bronchospasm is a potentially fatal side effect of beta-blocking drugs in asthmatic patients.
Heart failure is a side effect of beta blockers but occurs only when cardiac function is already compromised.
Beta-blockers can cause Raynaud’s phenomenon but breathing difficulty is not a symptom of Raynaud’s phenomenon.
Metabolic acidosis is something that can occur in diabetes. Beta-blockers can mask the symptoms of a hypoglycaemic attack in diabetics. However, there is no evidence that Carly was diabetic.
A condition or factor that increased the risk associated with taking a drug would be listed in the British National Formulary under the drug’s
cautions
The failure of Carly’s salbutamol inhaler to alleviate her breathlessness could be due to:
a. agonist actions of nadolol at beta 1 adrenoceptors b. antagonist actions of nadolol at beta 1 adrenoceptors c. agonist actions of nadolol at beta 2 adrenoceptors d. antagonist actions of nadolol at beta 2 adrenoceptors
d
Nadolol is a relatively non-selective beta-blocker. It will bind to beta-2 adrenoceptors in the bronchioles and may precipitate a bronchospasm. It will also competitively antagonise the salbutamol that Carly takes to try and relieve her asthma attack.
Nadolol antagonises beta-1 receptors to achieve its antihypertensive actions but they are not involved in broncho-constriction/dilation.
In primary (essential or idiopathic) hypertension, the cause is:
a. phaeochromocytoma
b. polycystic renal disease
c. renal artery stenosis
d. unknown
d
Although we know the risk factors for essential hypertension, it is not possible to identify a definitive cause. The other options are all disorders that can lead to hypertension. When the cause is known, the hypertension is called secondary hypertension.
Drugs that are catecholamines include:
[mark all correct answers]
a. acetylcholine
b. dopamine
c. isoprenaline
d. noradrenaline
b, c, d
Acetylcholine is not a catecholamine, it does not have a benzene ring with two OH groups (catechol ring). Dopamine, isoprenaline and noradrenaline all possess this structural feature.
Classes of clinically useful antihypertensive drugs include:
[mark all correct answers]
a. Beta-adrenoceptor antagonists
b. ACE inhibitors
c. sodium channel blockers
d. thiazide diuretics
a, b, d
Sodium channel blockers are not used clinically to treat hypertension though they are useful drugs in treating disorders of heart rhythm. Beta blockers, ACE inhibitors and diuretics are all useful antihypertensives.
First line treatments for hypertension include
[mark all correct answers]
a. ACE inhibitors
b. beta blockers
c. calcium channel blockers
d. lifestyle changes
a, c, d
For mild hypertension, NICE recommends lifestyle changes. For more serious hypertension, the first line treatments are either ACE inhibitors, calcium channel blockers or angiotension II receptor blockers (not an option here). Beta blockers are only tried when other drugs have failed.
Frusemide (aka furosemide):
[mark all correct answers]
a.
acts in the loop of Henle
b. causes marked potassium loss c. inhibits Na+/K+ ATPase in the luminal membrane of the proximal tubule d. is a high ceiling diuretic
a, b, d
Frusemide acts in the loop of Henle, not in the collecting duct. It inhibits Na+/K+/Cl- cotransport. It causes potassium loss leading to hyperkalaemia and is very powerful (high ceiling)
