CPT Flashcards
How do you calculate NNT?
1/absolute risk reduction
What can you do within an hour of paracetamol overdose?
Give activated charcoal to prevent absorption
Name the CYP450 Inducers
PCBRAS - Phenytoin, Carbamazepine, Barbituates, Rifampicin, Alcohol (chronic use), Sulfonylureas
Name the CYP450 Inhibitors
GODEVICES - Grapefruit juice, Omeprazole, Disulfiram, Erythromycin, Valproate, Isoniazid, Cimetidine, Alcohol (acute use), Sulphonamides
Effect on CYP inducers on COCP?
Cause it to be metabolised too quickly - higher dose required
Give 4 drugs that increase plasma statin
CYP3A4 involved- amiodarone, diltiazem and macrolides increase plasma statin
Amlodipine also increases plasma statin
Why is lidocaine given IV?
Extensive 1st pass metabolism
Why is lidocaine affected by CYP inhibitors/ inducers?
active metabolites require CYP activity
Why are you careful w fenofibrate and warfarin being prescribed together?
Increased anticoagulation
Administration of benzos?
Administration: Intravenous Lorazepam, Diazepam rectally, Buccal or intranasal Midazolam
How does digoxin work in HF?
Digoxin binds to and inhibits the sodium/potassium-ATPase (sodium pump) within the plasma membrane of cardiac myocytes. This inhibition increases the intracellular sodium content which in turn increases the intracellular calcium content which leads to increased cardiac contractility.
Effect of hypokalaemia on digoxin?
Increases its activity
Common side effect of potent anti-diarrhoeals?
Paralytic ileus
Common side effect of PPIs?
Mask symptoms of gastro-oesophageal cancer
PPI DDIs?
Δ Omeprazole CYP inhibitor – reduced clopidogrel action
PPIs can increase effects of warfarin and phenytoin - monitor
Sided effects of SABA and LABA ?
adrenergic - tachycardia, palpitations, anxiety and tremor
SVT due to decreased refractory period at AVN
What is the difference between typical and atypical antipsychotics?
Typical:- Block D2 receptors in all CNS dopaminergic pathways
- Main action as antipsychotics is on mesolimbic and mesocortical pathways
Atypical:- Low affinity for D2 receptors
- Milder side effects as dissociate rapidly from D2 receptor
- mixture of mood stabilisers and D2 antagonist
Give 2 contraindications for COCP
Current breast cancer
Smoking in age 35+
What % must Q risk be greater than for a statin to be prescribed? What should be done before starting a statin?
> 10%
LFTs at 3 and 12 months
What tx is someone switched to if they experience myalgia on statins?
Ezetimibe
Why might a vasoconstricting agent be used in conjunction with a local anaesthetic?
Increase duration of anaesthesia , decrease minimum effective dose required
Primary site of action of tiotropium?
M3 receptors
Pt info needed to create an appropriate chemotherapy regimen
BMI
Liver and renal function
Performance status
What are selegiline and rasagline used for in Parkinson’s?
MAO B inhibitors
First line in idiopathic Parkinson’s?
Co-carledopa (levodopa + dopa-decarboxylase inhibitor)
4 types of generalised seizure
Absence
Myoclonic
Tonic-clonic
Atonic
Effect of valproate on lamotrigine?
Increases its plasma conc
Stepwise management of acute (dangerous) asthma?
Oh Shit I Hate My Asthma
Oxygen Salbutamol (nebulised) Ipratropium bromide (nebulised) Hydracortisone iV or Oral Prednisolone Magneisum sulphate IV Aminophylline/ IV salbutamol
First line medical management for COPD?
Inhaled salbutamol/ ipratropium
First line management for non-concerning dyspepsia?
Trial omeprazole and review in 4 weeks
What should be prescribed alongside aspirin for a pt with a history of GORD?
Lansoprazole
How do you eradicate H Pylori? How to check eradication?
PPI + 2 abx ( amoxicillin + clarithromycin OR metronidazole + clarithromycin)
Urea breath test
Management for constipation?
Lifestyle - increase fibre and exercise
1st line - Isphagula husk
Then add or switch to macrogol
If macrogol ineffective then lactulose
Mechanism of action of methadone?
Mu- receptor agonist
Tx for infective exacerbation of COPD?
Amoxicillin or doxycycline if penicillin allergic
Foods to avoid in excess on warfarin?
Broccoli, spinach , kale and sprouts - contain high levels of vit K
What are sex steroids synthesised from? What receptors do they act at?
Cholesterol
Nuclear receptors that exert effects through gene transcription
Oestrogen has a membrane receptor
Classes of drug resistance
Multi-drug resistant (MDR)
- Non-susceptibility to at least one agent in three or more
antimicrobial categories
Extensively-drug resistant (XDR)
- Non-susceptibility to at least one agent in all but two or
fewer antimicrobial categories
Pan-drug resistant (PDR)
- Non-susceptibility to all agents in all antimicrobial categories
Betam lactam MOA and examples
Interfere with the synthesis of the bacterial cell wall peptidoglycan- Generally bactericidal
Penicillins
Cephalosporins
Carbapenems
What is co-amoxiclav?
AMOXICILLIN + CLAVULANIC ACID
Beta-lactamase = enzyme used by certain bacteria to
break down Beta-lactam antibiotic molecular structure
Clavulanic acid = Beta-lactamase inhibitor
Clavulanic acid is commonly combined with amoxicillin
in order to overcome this issue = Co-amoxiclav
How do tetracyclines work? Example?
Inhibit protein synthesis, bacteriostatic
Doxycycline
Tetracycline
Who can’t have tetracyclines?
Shouldn’t be given to children <12 years, pregnant and breastfeeding women
(causes staining of developing teeth)
Macrolide MOA? Examples?
Inhibit bacterial protein synthesis by an effect on ribosomal translocation- Bactericidal/bacteriostatic
Clarithromycin
Erythromycin
Azithromycin
Nitrofurantoin MOA?
Works by being reduced to multiple reactive intermediates by nitrofuran reductase inside the bacterial cell
These intermediates then attack ribosomal and DNA proteins within the bacteria, as well as inhibit the Citric acid cycle
Quinolones MOA and examples?
Inhibit topoisomerase II (a bacterial DNA gyrase), the
enzyme that produces a negative supercoil in DNA and
thus permits transcription or replication
Ciprofloxacin
Levofloxacin
Side effect profile for quinolones?
Tendinitis +/- rupture
Aortic dissection
Central nervous system effects (inc. Convulsions)
Give 2 agents that interfere with folate
Sulfonamides
Trimethoprim
Trimethroprim MOA?
Folate antagonist:
Reversible inhibitor of dihydrofolate reductase, which is necessary for the biosynthesis of bacterial nucleic acids and proteins
2 key examples of antivirals?
Aciclovir (DNA Polymerase Inhibitors)
Oseltamivir (Neuraminidase Inhibitors)
BB ADRs?
Mask tachycardia – sign of insulin induced hypoglycaemia
Bradycardia, heart block, Raynaud’s (cold hands), lethargy, impotence
Bronchospasm bc act at respiratory B receptors too
Valproate ADRs?
Liver failure
Pancreatitis
Lethargy
Effect of calcineurin inhibitors on TH2?
Prevents them producing IL2
calcineurin inhibitors ADRs?
renal toxicity ( check BP and eGFR regularly), gum hypertrophy
Digoxin contraindication?
X Heart block, renal failure, hypokalaemia (increased digoxin activity)
Diuretics that can cause hypokalaemia, amiodarone
Gliclazide drug class? How do they act?
Sulfonylureas
Block ATP dependent K+ channels to stimulate B-cell pancreatic insulin secretion
exenatide and liraglutide drug class?
GLP-1 receptor agonists (incretin mimetics)
Verapamil contraindications?
X Poor LV function (caution), AV nodal conduction delay
Other name for gliptins?
Dipeptidyl peptidase-4 (DPP-4) inhibitors
MOA of glitazones?
Insulin sensitisation in muscle and adipose, ↓hepatic glucose output by activation of PPAR-γ → gene transcription
Which diabetes drug has the mad side effects?
Glitazones - GI upset, fluid retention, fracture risk, bladder cancer AND weight gain because of fat call differentiation
How does fenofibrate help with hyperlipidaemia?
Activation of nuclear transcription factor – PPARα- which regulates expression of genes that control lipoprotein metabolism = increase production of lipoprotein lipase
↑triglycerides removal from lipoprotein in plasma ↑fatty acid uptake by the liver
Ezetimibe MOA?
Inhibit NPC1L1 transporter at brush border in small intestines
dipyridamole drug class? MOA?
Phosphodiesterase inhibitor
inhibits cellular reuptake of adenosine → increased [adenosine] → inhibits platelet aggregation via adenosine (A2) receptors
Also acts as phosphodiesterase inhibitor which prevents cAMP degradation → inhibit expression of GPIIb/IIIa
Corticosteroids for N&V?
Dexamethasone and Methylprednisolone
Examples of LMWH?
dalteparin, enoxaparin and fondaparinux
ADRs of LMWH?
Bruising and bleeding- Intracranial, at site of injection, GI, epistaxis
HIT
Hyperkalaemia- aldosterone inhibition
Osteoporosis- more in pregnancy
Give examples of DOACs
apixaban edoxaban and rivaroxaban-Inhibit both free Xa and that bound with ATIII
What is amiloride?
potassium sparing diuretic
Why is warfarin avoided in pregnancy?
It crosses the placenta – avoided at least in 1st (teratogenic) and 3rd (haemorrhage) trimesters
Main contraindication for metformin?
excreted unchanged by kidneys – stop if eGFR < 30 mL/min, alcohol intoxication
Levetiracetam MOA?
Synaptic vesicle glycoprotein binder. Stops the release of neurotransmitters into synapse and reduces neuronal activity
What increases peripheral breakdown of levodopa?
Pyridoxine (vitamin B6)
Atropine MOA?
Antimuscarinic – blocks M2 receptors (vagal activity) increasing firing of SA node and conduction through AV node
Dihydropyridine CCB contraindications?
X Unstable angina, severe aortic stenosis
Special Dihydropyridine CCBs?
amoldipine has a longer half life than the others, nimodipine is selective from cerebral vasculature so can be used in subarachnoid haemorrhage
Adenosine MOA?
A1 receptor agonist – activate K+ channels enhancing flow out of cells causing hyperpolarisation
Slows conduction through AVN
Rituximab use in RA?
Binds to CD20 found on a subset of B cells, causes B cell apoptosis
Methotrexate MOA? Side effects?
Competitively inhibits DHFR ( needed for purine and thymidine synthesis), inhibits DNA and RNA synthesis, cytotoxic ( however mechanism in non malignant disease is uncertain)
ALL the itis things
