Actions Of Drugs On Cardiovascular Physiology Flashcards
What is propranolol ?
Non selective beta blocker/antagonist
What is salbutamol ?
Beta-2 selective agonist
What is glyceryl trinitrate ?
A nitric oxide donor
What effects did propranolol have on the cardiovascular system ?
Reduces HR by blocking sympathetic activity
Can causes bronchoconstriction by blocking beta-2 receptors at tracheal smooth muscle preventing vasodilation
Block beta -2 receptors in blood vessel walls preventing vasodilation so promoting vasoconstriction
Reduction in systolic and diastolic blood pressure
Why can propranolol not be given to asthmatics or people with a resting heart rate of 70 bpm or less ?
Because it can block the beta-2 adrenoreceptors in tracheal smooth muscle and prevent vasodilation which can be dangerous because it can reducing breathing abilities in asthmatics
Can’t be used in people with low resting heart rates because it reduces the heart rate and this could reduce the amount of blood reaching tissues reducing oxygen and nutrient delivery and carbon dioxide delivery - could also reduce amount of oxygen in coronary circulation which could cause ischaemia of the heart
What are the exclusion criteria for propranolol ?
Asthma/ history of breathing problems Psoriasis -skin disease marked by red itchy scaly patches Pregnancy/breast feeding Heart disease Diabetes mellitus Liver disease Renal impairment Myasthenia gravis Phaeochromocytoma History of hypersensitivity
What side effects have been reported with propranolol ?
Bradycardia, fatigue, hypotension, conduction disorders, bronchospasm, peripheral vasoconstriction, gastro-intestinal disorders, sleep disturbances, rashes and dry eyes
What are the exclusion criteria for salbutamol ?
Known heart disease or hypertension
Diabetes mellitus
Hyperthyroidism
Pregnancy p/breast feeding
What drugs will interact with salbutamol ?
Corticosteroids
Diuretics
Theophylline -oral bronchodilator
What effects were we expecting from salbutamol in our experiment ?
Flushing of the face Hand tremor Rise in systolic blood pressure Fall in diastolic blood pressure Small tachycardia - maybe palpitations
What are the side effects of salbutamol ?
Fine tremor, headache, peripheral vasodilation, palpitations, tachycardia, muscle cramps, hypokalaemia and very rarely hypersensitivity reactions
Why does GTN have to be taken sublingually ?
Because if it was taken in as a tablet it would undergo 100% first pass metabolism
What are the exclusion criteria for GTN ?
Heart disease or hypotension Anaemia Glaucoma Hypothyroidism Recent significant head injury Known liver impairment Known renal impairment Pregnancy/breast feeding Hypersensitivity to nitrates
What effects were we expecting to occur after GTN administration ?
Flushing of the face
Fall in both systolic and diastolic blood pressure
Small tachycardia and may feel palpitations
Short lived headache
What are the side effects of GTN ?
Throbbing headache, flushing, dizziness, postural hypotension and tachycardia
