Pharmacology Flashcards
Ramipril - class and mechanism
- ACEi = enalapril, lisinopril, captopril
- Competitive inhibitor
- Inhibits synthesis of AG2 which is a vasoconstrictor
- Therefore = vascular smooth muscle relaxation and vasodilation
ACEi - dose
- initially 1.25 - 2.5mg once daily for HTN
- Can be increased to 10mg a day
ACEi SE and contraindications
- SE = persistent dry cough, hyperkalaemia, renal failure
- CI = caution if on diuretics or renal impairment, pregnancy
ACEI monitoring
- renal function and electrolytes before starting and during treatment
BB - examples and mechanism
- Bisoprolol, atenolol, metoprolol
- target beta adrenoreceptors in heart, peripheral vasculature, bronchi
- Competitive antagonist
- Inhibits binding of normal ligand noradrenaline released from sympathetic adrenergic neurons –> inhibits activation of adenylyl cyclase enzymes –> reduced CAMP
–> reduced intracellular Ca - Reduced contractility, reduced heart rate
BB dose
- Angina = 5mg OD up to 10
- HF = 1.25 and increase
BB SE + contraindications + monitoring
- SE = dizziness, fatigue, impotence
- CI = COPD, asthma, DM, heart block
- Probably not in preg and BF
- Monitor lung function in COPD
CCB examples and mechanism
- amlodipine, felodipine, lercanidipine, nidefipine
- Antagonist
- Inhibits influx of ca into vascular smooth muscle cells through L type Ca channels
- Therefore decreased arterial smooth muscle contractility –> vasodilation
CCB dose
- Initially 5mg OD and increase to 10mg
CCB SE and contraindications
- CI = cardiogenic shock, aortic stenosis, unstable angina
- SE = abdo pain, dizzy
ARB examples and mechanism
- Candesartan, losartan, valsartan
- Competitive antagonist
- Selective inhibition of potent vasoconstrictor peptide angiotensin 2
- Vascular smooth muscle and vasodilation
ARB dose
Candesartan = start 4mg, maintenance 8-32mg
Losartan = 50mg OD
ARB SE and CI
- Hypotension
- CI = aortic of mitral stenosis
- No in pregnancy or BF
- Monitor renal function
Aspirin mechanism of action
- Targets cyclooxygenase enzymes
- Irreversible inhibitor
- Impairs synthesis of thromboxane A2 and prostacyclin within platelets
- Therefore reduces platelet aggregation
Aspirin dose
75mg for secondary prevention
Aspirin SE and CI
- CI = peptic ulcer, bleeding disorders, under 16s, haemophilia, asthma
- SE = GI irritation, ulceration and bleeding, bronchospasm
Clopidogrel mechanism of action
- ADP receptor pathway inhibitors
- Irreversible inhibitor of ADP receptor
- Inhibits binding of ADP to platelet receptor –> inhibits platelet aggregation
Clopidogrel dose
75mg for prevention
ACS = 300-600mg loading dose
Clopidogrel SE and CI
- CI = active bleeding, caution in hepatic and renal impairment
- Avoid in pregnancy
- SE = GI discomfort
Statin mechanism of action
- HMG co-enzyme A reductase inhibitors
- Competitive inhibitor
- inhibition if HMG co-enzyme A reductase reduces hepatic cholesterol synthesis through mevalonate pathway
- Upregulation of LDL receptor and increased hepatic removal of LDL from circulation
Statins dose
10mg OD and can increase to 80
Statins monitoring, SE and CI
- CI = caution if myositis/rhabdomyolysis or liver disease
- No in pregnancy
- SE = arthralgia, GI
- Monitoring = lipid profiles, LFTs, CK
LMWH examples and mechanism of action
- Enoxaparin, dalteparin, tinzaparin
- Inhibit factor Xa which is needed to convert prothrombin to thrombin, therefore coagulation inhibited
- DOAC = anticoagulant
LMWH dose
- VTE pregnancy = 40-100mg 2X
- DVT prophylaxis = 20mg - 40mg
- DVT/PE tx = 1.5mg/kg every 24hrs
LMWH SE and CI
- CI = endocarditis, trauma, renal impairement, haemorrhagic disorders
- SE = haemorrhage, thrombocytopenia
What can happen when restarthing levothyroxine after a cessation?
- CO suddenly increases
- Angina, palpitations, SOB, HF
- So should be reinitiated at a low dose and gradually increased
NSAID examples and mechanism
- ibuprofen, naproxen, diclofenac
- Target cox-2 enzymes and cox-1 isoform also affected
- Inhibit cix-mediated conversion of arachidonic acid to prostaglandins and thromboxanes = vasodilation, oedema, pain
NSAID dose
- Ibuprofen = 300-400mg 3-4 times a day
- Naproxen = 0.5-1g daily in rheumatic
NSAID SE and CI
- Gastric irritation, ulceration and bleeding
- Compromised renal blood flow
- Caution in asthma
Paracetamol mechanism of action
inhibits synthesis of prostaglandins from arachidonic acid = cox3 enzyme
- peripherally blocks generation of pain impulses, reduced central pain signalling
paracetamol dose
0.5-1g every 4-6 hours, max 4g daily
PPI examples and mechanism of action
- lansoprazole, pantoprazole, omeprazole
- target H K ATPase pump at the secretory surface of gastric parietal cells
- Irreversible inhibitor = inhibits final transport of hydrogen ions into gastric lumen
PPI dose
- 20-40mg
PPI SE and CI
- GI disturbance
- rebound acid hypersecretion
- if red flags rule out GI malignancy before prescribing
Antiplatelet examples and mechanism of action
- Clopidogrel, prasugrel
- inhibits binding of adp to platelet receptor therefore prevents platelet aggregation
Antiplatelet dose
- secomdary prevention 75mg
- loading dose for MI 300mg
Antiplatelet SE and CI
- GI disturbance
- not in pregnancy
- caution in hepatic and renal impairment
Loop diuretics examples and mechanism of action
- furosemide, bumetanide
- competitive inhibitor at the chloride binding site of the symporter
- prevents transport of sodium from the lumen of loop of henle = diuresis
Loop diuretic dose
- 20-40mg for oedema
- 80mg for resistant htn
Loop diuretic se and ci
- postural hypotension, electrolyte disturbances = hypok
- caution in hypovolaemia
- avoid in anuria, hypona/k
K sparing diuretics and mechanism of action
- spironalacton and epleronone
- competitive antagonist targets intracellular aldosterone receptors in renal tubules
K sparing dose
- HF = 25-50mg
- ascites = 50BD - 200BD
K sparing SE and CI
- GI upset, hyperk
- avoid in addisons
Thiazide diuretic SE and CI
- hypokalaemia
- hyponatraemia
- hypercalcaemia and glycaemia
- gout
- avoid in addisons
thiazide diuretics examples and MoA
- bendroflumethiazide, indapamide
- inhibitor, targets Na Cl symporter in DCT, inhibits NaCl reabsorption therefore reduce BV and rpessure
thiazide diuretic dose
- Bendro = 5-10mg for oedema, 2.5 for HTN
aminosalicylates examples and MoA
- mesalazine, sulfasalazine
- inhibits prostaglandin production = reduces colonic inflammation
SE and dose for mesalazine
- GI upset
- 1.2 - 4.8g until remission then 2.4g
SSRI exmaples and MoA
- fluoxetine, sertraline, citalopram
- prevents re-uptake of serotonin from cleft = prolonged serotonin = prolonged neuronal activity
SSRI SE and CI
- GI upset
- anorexia
- Bleeding
- NMS
- CI = epilepsy, DM, pregnancy, mania
Sertraline dose
- 50mg OD then increase in 50mg to max 200
TCA examples and MoA
- amitryptilline, nortryptilline
- increased presence of serotonin and noradrenaline in cleft
amitriptyline dose
- 75mg daily starting dose
- 150-200mg
amitryptilline SE and CI
- antimuscarinic, weight gain, abdo pain
- cardiotoxic in overdose
- CI = hepatic, elderly, suicude risk, epilepsy
dopamine antagonist anti-emetics
- domperidone
- mecoclopramide 10mg up to 3Xd
- prokinetic effect on GI tract
- extrapyramidal sx
antihistamine anti-emetics
- cyclizine 50mg up to 3xd
- antimuscarinic
5 hydroxytryptamine anti-emetics
ondansetron = for emetogenic chemotherapy = 8mg 1hr prior
- consitpation, flushing
benzodiazepines examples and MoA
- diazepam, lorazepam
- hyperpolarization = further excitation
SE and Ci diazepam dose
- amnesia, ataxia, confusion
- psychomotor impairement
- rep depression
- 2mg increased to 15-30mg if needed
salbutamol MoA
- bronchial smooth muscle relaxation and bronchodilation
salbuamol SE and CI
- fin tremor, headaches, cramps
- hypokalaemia
salbutamol doses
- ingaler = 100-200mcg 4xd
- nebs = 2.5 - 5mg 4xd
- powder 200-400mcg 4xd
alendronic acid moa, dose, se
- bisphosphonate
- prevents further reduction in bone mass
- 10mg daily
- SE = gi, oesophagitis, necrosis jaw
- empty stomach, 30mins pre breakgast
corticosteroids moa
- upregulation of gene transcription
