Asprin - Flashcards
Aspirin mechanism
Irreversibly inhibits cyclooxygenase -> reduces platelet aggregation
Aspirin adverse effects ? Regular high dose ?
GI irritation -> ulceration / haemorrhage
Hypersensitivity -> bronchospasm
Regular high dose -> tinnitus
Why should children under 16 not get aspirin ?
Risk of Reye’s syndrome
Affects liver and brain
Why should aspirin not be given in third trimester of pregnancy
Prostaglandin inhibition -> premature closure of ductus arteriosus
When should you be cautious giving asthma
Peptic ulceration
Gout
Aspirin interactions
Can act synergistically with other antiplatelets
Eg. Clopidogrel , heparin, warfarin
Aspirin prescription in acute coronary syndrome
Loading dose of 300mg followed by 75mg once daily
Aspirin prescription for ischemic stroke
300mg daily for 2 weeks -> 75mg daily
Aspirin prescription for long term prevention of thrombosis
75mg daily
What should often be given wi aspirin ? Especially if on what other drugs
Gastroprotection eg omeprazole 20mg daily.
Other drugs - prednisolone /NSAIDS
Benzodiazepines egs.
Diazepam, temazepam, lorazepam, chlordiazepoxide, midazolam
Benzodiazepines uses
First line seizures and status epilepticus
Alcohol withdrawal
Sedation if general anaesthesia undesirable
Short term treatment of severe anxiety / insomnia
Benzodiazepines mechanism
Facilitate and enhance binding of GABA to GABAa receptor
Benzodiazepines adverse effects
Drowsiness, sedation and coma.
Benzodiazepine overdose ->
Loss of airway reflexes -> obstruction
Long term benzodiazepine use ->
Dependence and withdrawal reaction similar to alcohol
Caution giving benzodiazepines to?
Elderly
Respiratory impairment / neuromuscular diseas
Liver failure
Benzodiazepines interactions
Additive to other drugs causing sedation Eg. Alcohol, opioids.
Cytochrome p450 inhibitors (increases effect)
Cytochrome p450 inhibitors
Amiodarone, diltiazem, macrolides, fluconazole
Which benzodiazepines for seizures
Longer acting - lorazepam 4mg IV, diazepam 10mg IV
Benzodiazepines for alcohol withdrawal
Diazepam or chlordiazepoxide
Benzodiazepines for sedation
Short acting - midazolam
Benzodiazepines for insomnia / anxiety
Intermediate acting - temazepam 10mg oral
Antagonist of benzodiazepines
Flumazenil
Beta 2 agonists egs
Salbutamol, salmeterol, formoterol, terbutaline
B2 agonist uses
Asthma, COPD, hyperkalaemia
B2 agonist mechanism
Smooth muscle relaxation
Stimulate Na/K-ATPase pumps - K from extra cellular -> intracellular
B2 agonist adverse effects
Tachycardia, palpitations, anxiety, tremor (fight or flight)
Long acting - muscle cramps
What’s needed with long acting b2 agonist in asthma
Inhaled corticosteroid
Cation with b2 agonists in who?
Cv disease
B2 agonist interactions
B blockers prevent.
Corticosteroids -> hypokalaemia
When giving nebuliser for COPD / asthma, do you give with oxygen or air?
Asthma - oxygen
COPD - air as risk of co2 retention
Beta blockers egs
Bisoprolol, atenolol, propranolol, metoprolol
B blocker uses
Ischemic heart disease, chronic heart failure, AF, supra ventricular tachycardia.
Hypertension
B blocker mechanism
Reduce force of contraction and speed of conduction in heart .
Prolong refractory period of AV node.
Reduce renin secretion
Who should never get b blockers
Asthma
Heart block
Caution using b blockers in who
COPD -(use b1 selective eg atenolol, bisoprolol, metoprolol)
Heart failure
Heamodynamic instability
Hepatic failure
B blocker important interaction
Don’t use with non-dihydropyridine calcium channel blockers -> heart failure and bradycardia
Aspirin uses
Acute coronary syndrome and acute ischemic stroke.
Long term prevention of thrombotic arterial events
AF when warfarin is contraindicated
Mild to moderate pain / fever
BisPhosphonates egs
Alendronic acid, disodium pamidronate, zolendronic acid
Bisphosphonates uses
Osteoporosis
Hypercalcaemia of malignancy
Myeloma / breast cancer with metastases
Pagets
Bisphosphonates mechanism
Inhibit action of osteoclasts -> reduce bone turnover
Bisphosphonates adverse effects
Oesophagitis, hypophosphataemia
Rare - osteonecrosis of jaw (good dental hygiene needed), atypical fracture of femur
Who should never get BisPhosphonates
Severe renal impairment
Hypocalcaemia
Upper GI disorders
Due to risk of osteonecrosis who should BisPhosphonates be caution in?
Smokers
Dental disease
What can limit BisPhosphonate absorption
Calcium salts eg milk / antacids
As BisPhosphonates bind calcium
Alendronic acid for osteoporosis prescription
70mg once weekly
Bisphosphates prescription for Hypercalcaemia and bone metastases
Disodium / zolendronic acid as slow IV infusions (takes several days for results)
How should alendronic acid tablets be taken
30 mins before food with plenty water
Stay standing for 30 mins to reduce oesophageal irritation
What should be done before BisPhosphonate treatment in osteoporosis
Check and replace calcium / vit D
Calcium and vit D uses
Osteoporosis Chronic kidney disease Severe hyperkalaemia Symptomatic hypocalcaemia Vit D deficiency
Why calcium and vit D in CKD
Prevent and treat secondary hyperparathyroidism / renal osteodystrophy
Calcium and vit D egs
Calcium carbonate, calcium gluconate, colecalciferol, alfacalcidol
What controls calcium homeostasis
Parathyroid hormone and vit d
Calcium adverse effects
Constipation and dyspepsia
Calcium gluconate adverse effect
If given too quickly IV for hyperkalaemia -> cv collapse and local tissue damage if accidentally given IM
Which drug cannot be mixed with IV calcium
Sodium bicarbonate (risk of precipitation - solid formed from liquid solution)
Oral calcium interactions
Reduces absorption of many drugs eg. BisPhosphonates, tetracycline, levothyroxine
Prescription of calcium and vit d in osteoporosis
1g of calcium and 800 units of vit D
Hyperkalaemia - calcium prescription
10ml of calcium gluconate IV
Calcium channel blockers egs
Amlodipine, nifedipine, diltiazem, verapamil
Calcium channel blockers uses
Stable angina
Diltazem / verapamil - supraventricular arrythmias
Amlodipine / nifedipine - hypertension
Calcium channel blockers mechanism
Relaxation and vasodilation in arterial smooth muscle
Reduce myocardial contractility
Suppress cardiac conduction
Reduce myocardial oxygen demand
Amlodipine / nifedipine adverse effects
Ankle swelling, flushing, headache, palpitations
Verapamil adverse effects
Constipation
Rarely - bradycardia, heart block, Cardiac failure
Diltazem adverse effects
Same as Amlodipine nifedipine, verapamil
As has vascular and cardiac actions
Amlodipine and nifedipine should never be given to who
Unstable angina
Severe aortic stenosis
Verapamil and diltiazem should be used in caution with who
Poor LV function
AV node conduction delay
Amlodipine hypertension prescription
5-10mg orally
Angina diltiazem prescription
90mg orally 12 hourly
Verapamil prescription for supraventricular arrhythmia
40-120mg 8 hourly
Carbamazepine uses
Epilepsy - focal with /out 2 generalisation. 1 generalised
Trigeminal neuralgia
Bipolar disorder
Carbamazepine mechanism
Inhibits neuronal sodium channels
Carbamazepine adverse effects
GI upset, dizzy and ataxia, oedema, hyponatraemia.
Rarely - antiepileptic hypersensitivity syndrome
What is antiepileptic hypersensitivity syndrome
After taking carbamazepine / phenytoin -> eg Stephen Johnson / fever / lymphadenopathy
Caution giving carbamazepine to who
Pregnant
Hepatic, cardiac or renal disease - toxicity
What enzyme is induced by carbamazepine ? Egs of drugs reduced
Cytochrome p450
Warfarin, oestrogens, progesterones
What increases effects of carbamazepine (caution)
P450 inhibitors (as metabolised) eg macrolides
What reduces efficacy of antiepileptics ? Egs
Drugs that lower seizure threshold eg SSRIs, tricyclics, antipsychotics, tramadol
Prescription of carbamazepine
Start at low dose 100-200mg 12hrly
Increase gradually up to max 1.6g / day
Usual first choice drug for focal seizures
Carbamazepine
Cephlasporins eg
Cefalexin, cefotaxime
Carbapenems egs
Meropenem, ertapenem
Cephasporins and carbapenems uses
Severe / complicated / antibiotic resistant infections
2nd line for uti / Rti
Cephlasporins / carbapenems mechanism
Due to thier b lactam ring -> bacterial swelling, lysis and death
Resistance to b lactamases
Carbapenems / cephlasporins adverse effects
C. difficile
Hypersensitivity
Risk of CNS toxicity -> seizures
Caution for carbapenems / cephlasporins
Epilepsy / renal impairment
NEVER if anaphylaxis to penicillins
Cephlasporins / carbapenems interaction
Increase warfarin (as kills gut flora that synthesise vit k) Reduce valproate
Clopidogrel uses
Acute coronary syndrome
Prevent occlusion of coronary artery stents
Long term prevention of thrombotic arterial disease
Reduce risk of embolism from AF
Clopidogrel mechanism
Prevents platelet aggregation by binding to adenosine diphosphate (ADP) receptors
What is usually prescribed alongside clopidogrel
Aspirin as clopidogrel doesn’t effect COX pathway so synergistic together
Clopidogrel adverse effects
Bleeding
GI upset
Thrombocytopenia
How long before elective surgery should clopidogrel be stopped
7 days
When should be cautious for clopidogrel
Renal / hepatic impairment
What needs to happen for clopidogrel to be activated
Requires metabolism by p450
P450 inhibitors egs
Omeprazole, Ciproflaxacin, erythromycin, some antifungals, SSRIs
Clopidogrel dose
75mg daily (May need loading dose 300mg
Compound b2-agonist - corticosteroid inhalers adverse effects
Local - horse voice, oral thrush
Long term - systemic from steroids
B2 - tremor, tachycardia, muscle cramps
Systemic effects from long term inhaled corticosteroids
Adrenal suppression, growth retardation in children, osteoporosis
Cautious of combined inhalers in who
COPD with Hx of pneumonia (increased risk)
Children (growth)
Cv disease
Egs of combined inhalers
Seretide, symbicort
Tell Pt getting combined inhalers
Need to take without fail - takes hours / days to notice improvement
Rinse mouth and gargle to help mouth side effects
Egs of systemic corticosteroids
Prednisolone, hydrocortisone, dexamethasone
Systemic glucocorticoids uses
Allergy / inflammatory
Autoimmune
Cancer - reduce tumour related swelling
Hormone replacement - adrenal insufficiency / hypopituitarism
Adverse effects of systemic corticosteroids
Immunosupression
Metabolic - diabetes / osteoporosis
Weakness, easy bruising, mood and behavioural
Mineralcorticoid - hypertension, hypokalaemia, oedema
Adrenal atrophy (suppression of ACTH from pit)
Sudden withdrawal of systemic corticosteroids ->
Addisonian crisis -> cv collapse
Cautious with systemic corticosteroids in who
People with infection
Children (growth)
Systemic Corticosteroids mechanisms
Upregulate anti inflammatory
Down regulate pro inflammatory
Metabolic - increased gluconeogensis from catabolism of muscle / fat
Mineralcorticoid - Na / water retention and k excretion
What drugs reduce efficacy of systemic corticosteroids
P450 inducers - phenytoin, carbamazepine, rifampicin
Which is the most potent systemic corticosteroid
Dexamethasone (750 micrograms = pred 5mg = hydro 20mg)
What to tell patients getting systemic corticosteroids
Not to stop suddenly
Should start to feel better in 1-2 days
Inhaled corticosteroid egs
Beclometasone, budesonide, fluticasone
Inhaled corticosteroid effects in lungs
Reduces mucosal inflammation, bronchodilation, reduce mucus secretion
Adverse effects of inhaled corticosteroids
Oral thrush
Horse voice
May increase risk of pneumonia
Inhaled corticosteroid caution in
Hx of pneumonia
Children
Inhaled corticosteroid how many times daily
Twice
Needs to be checked with any inhaler
Technique
Poorly controlled airway inflammation in asthma ->?
Airway remodelling
Topical corticosteroid egs
Hydrocortisone
Betamethasone
Topical corticosteroid uses
Eczema / inflammatory skin conditions
Local adverse effects of topical corticosteroids
Skin thinning
Telangiectasia
Contact dermatitis
Withdrawal of topical corticosteroids
Rebound worsening of underlying condition
Should not use topical corticosteroids in who
Where infection
Facial lesions
How to use right amount of corticosteroid cream
Squeeze tip of finger to first crease -> area double size of Palm