medical history Flashcards
what is propranolol’s mechanism of action
blocks B1 and B2 receptors
stops arrhythmias that could lead to cardiac arrest (ventricular fibrillation) by stopping heart muscle excitation
prevents increase in heart rate so can cause postural hypotension and worsen heart failure or asthma (there are B2 receptors in the lungs)
what is ramipril’s mechanism of action
angiotensin converting enzyme inhibitor that prevents the conversion of angiotensin I into angiotensin II, and prevents the aldosterone dependent resorption of salt and water
used to lower blood pressure
can have side effects of cough, hypotension, lichenoid reactions, angio-oedema
losartan is an angiotensin II blocker that inhibits the same system but by a different mechanism
what is clopidogrel’s mechanism of action
anti platelet drug that inhibits platelet aggregation for the lifetime of the platelet (7-10 days)
often used in conjunction with aspirin to reduce the risk of MI or stroke
inhibits ADP induced platelet aggregation
aspirin increases prostacyclin and reduces thromboxane A2
prolongs bleeding time following extraction
give examples of new oral anti coagulants and the mechanism of each
rivaroxaban - activated factor X inhibitor; taken once a day
apixaban - activated factor X inhibitor; taken twice a day
dabigatran - direct thrombin inhibitor; taken twice a day
all have a short half life so their effect is rapidly lost
no anticoagulant test is used as they have predictable bioavailability
patients may only been on them for a short course (eg deep vein thrombosis) so postpone extraction until stopped
interact with erythromycin and clarithromycin (macrolide antibiotics); and NSAIDs will prolong their action
what is warfarin’s mechanism of action
coumarin based vitamin K antagonist inhibits the formation of clotting factors 2, 7, 9, 10
initial hypercoagulation (first 2-3 days) then bleeding risk
monitored with INR (should be <4 within 24h pre op)
patient may be on heparin initially to prevent hyper coagulation
always use local haemostasis measures for patients on warfarin
all drugs interact
what is the mechanism of action of frusemide
loop diuretic that treats hypertension and heart failure
increases salt and water loss to reduce plasma volume and reduce cardiac workload
can lead to Na/K imbalance, or dry mouth in the elderly
what is the mechanism of action of simvastatin
inhibits cholesterol synthesis in the liver to reduce total and LDL cholesterol levels
inhibits the enzyme in the liver that produces cholesterol
can cause thrombocytopenia and anaemia
can lead to myositis (interacts with anti fungals like fluconazole)
it is a prodrug so ingested in its inactive form then metabolised to become activated
what is the mechanism of action of amlodipine
Ca channel blocker that relaxes smooth muscle (cause vasodilation) to reduce hypertension
can lead to gingival hyperplasia (so can cyclosporin and phenytoin)
what is the mechanism of action of salbutamol
blue inhaler
short acting beta agonist used to treat acute asthma by achieving bronchodilation
emergency use to treat bronchial constriction (2-3m onset; 4-6h half life)
can cause erosion as contains sulphuric acid
what is the mechanism of action of salmeterol
green inhaler
long acting beta agonist that is used to prevent bronchial constriction
always used with an inhaled steroid
slow onset 1-2h; lasts 12-15h
what is the mechanism of action of ipratropium
grey inhaler
anticholinergic that inhibits muscarinic nerve transmission in autonomic nerves
additive effect in bronchial dilation and reducing mucous secretion
what is the mechanism of action of betamethasone when used to treat respiratory disease
brown inhaler
reduces inflammation in the bronchial walls
effective topically or systemically
can cause dry mouth and risks fungal infections in the mouth
what is the mechanism of action of seretide
compound preparation of inhaled steroid (fluticasone) and a long acting beta agonist (salmeterol)
what is the mechanism of action of chromoglycate
mast cell stabiliser prevents degranulation
what is the mechanism of action of metformin
insulin sensitiser (biguanide)
enhance cell insulin sensitivity
reduce hepatic gluconeogensis (glucose being produce in the liver)
preferred in the obese
can cause wit B12 deficiency if taken for a long time
what is the mechanism of action of amitriptyline
tricyclic antidepressant that increases norepinephrine and serotonin neurotransmitters
block acetylcholine action
cause xerostomia, agranulocytosis (low WBC count leading to infection risk), bone marrow suppression (low platelet and RBC count so bleeding risk)
what is the mechanism of action of aledronic acid
bisphosphonate drug that inhibits osteoclast action to reduce bone turnover in osteoporosis patients
can cause MRONJ (review all extraction patients after 8 weeks)
what is the mechanism of action of denosumab
a fully human monoclonal antibody that inhibits osteoclast function and associated bone resorption by binding to RANKL
administered subcutaneously every 6 months in osteoporosis patients
its effects on bone turnover diminish 9 months after treatment completion
what is the mechanism of action of citalopram
selective serotonin reuptake inhibitor that is used to treat depression or panic disorder
can cause dry mouth, altered taste, arrythmias
what is the mechanism of action of omeprazole
proton pump inhibitor that inhibits stomach acid secretion by parietal cells
if taking for more than a year the patient can be at risk of vital B12 deficiency (mouth ulcers) and bone fractures
what is the mechanism of action of allopurinol
used to treat gout by lowering uric acid levels
can cause agranulocytosis
what is the mechanism of action of gabapentin
reduces excitability of nerve cells in the brain to treat seizures and chronic pain
can cause xerostomia or leucopenia
what is the mechanism of action of isosorbide mononitrate
long acting nitrate that prevents angina pectoris
short acting glyceryl trinitrate is used in an emergency to treat angina pectoris by dilating veins, dilating resistance arteries, and dilating collateral coronary artery supply
nitrates are inactivated by first pass metabolism and have side effects of headache
