Pass the PSA Flashcards
Enzyme inducers - mnemonic
PC BRAS
Phenytoin, Carbamazepine, Barbituates, Rifampicin, Alcohol, Sulphonylureas
Enzyme Inhibitors - mnemonic
AODEVICES
Allopurinol, Omprazole, Disulfiram, Erythromycin, Valproate, Isoniazid, Ciprofloxacin, Ethanol (acute), Sulphonamides
Drugs To stop before surgery - mnemonic
I LACK OA
Insulin, Lithium (day before), Anticoag/plt, COCP/HTR (4/52 before), ACEi and K sparing diuretics (day of)
CI to NSAIDs - mnemonic
NSAID No urine Systolic dysfunction Asthma Indigestion Dyscrasia (clotting abnormality) * Aspirin although NSAID, is not CI in RF, HR, asthma
Fluid replacement: which fluid?
All pts 0.9% saline unless:
Hypernatreamia or hypoglycaemia - use 5% dextrose
Ascites - use human albumin solution (HAS, in saline high Na content will worsen ascites)
Shocked - gelofusine (colloid)
Bleeding - like for like but colloid first if no blood available
Principles of fluid replacement
Start by assessing HR, BP, UO
If tachycardic/hypotensive = 500ml STAT (250ml if HF) then reassess
If only oliguric w/o obstruction = 1L / 2-4hrs and reassess
Reduced UO = 500ml depletion
Reduced UO + tachycardia = 1L depletion
Reduced UO + tachy + hypo = 2L depletion
Do not prescribe >2L at once, needs to be reassessed
Principles of fluid maintenance
Adults = 3L fluid (8h bag); Elderly 2L fluid (12h bag)
1 salt 2 sweet = 1L saline and 2L 5% dextrose for daily
K = 40mmol/day, so put 20mmol at a time into bad (max rate 10mmol/h)
Reassess OU, overload, obstruction
CI to DVT prophylaxis
Majority of pts LMWH and TED stockings
Recent ischaemic stroke - no blood thinning for 2 months
Peripheral arterial disease - no TED
When to avoid metoclopramide?
PD patients (it is Da antagonist), will exacerbate symptoms (domperidone is also Da antagonist but does not cross BBB so more safe) Young women, risk of dyskinesia (esp acute dystonia)
Antiemetic choices - first line
Cyclizine 50mg TDS IV/IM/PO but causes fluid retention
Metoclopramide 10mg up to TDS if HF
Pain relief - example
WHO ladder
Paracetamol 1g up to QDS ± Codeine 30mg up to QDS ± Morphine sulphate 10mg up to QDS (usually Oromorph 10mg/5ml)
Neuropathic pain = amitryptilline 10mg PO nightly or pregabalin 75mg BD
Diabetic neuropathy = duloxetine 60mg PO OD
Causes of thrombocytopenia
- Reduced production (infection esp viral, penicillamine in RA pt, myelodysplasia, myelofibrosis, myeloma)
- Increased destruction (heparin, hypersplenism, DIC, ITP, HUS, TTP
Causes of hyponatraemia
- Hypovolaemic (fluid loss esp D&V, addison’s, diuretics)
- Euvolaemic (SIADH, psychogenic polydipsia, hypothyroid)
- Hypervolaemic (HF, RF, low albumin, hypothyroid(
Causes of SIADH - mnemonic
SIADH SCLC Infection Abscess Drugs (carbamazepine and antipsychotics) Head injury
Causes of Hypokalaemia - mnemonic
DIRE Drugs (loop and thiazide diuretics) Inadequate intake / loss (D&V) RTA Endocrine (cushing's and conn's)
Causes of Hyperkalaemia - mnemonic
DREAD Drugs - K sparing diuretics and ACEi Endocrine - addison's Artefact (clotted sample) DKA
Raised urea indicates?
AKI or Upper GI haemorrhage
Types and causes of AKI
Pre-renal (70%): dehydration, sepsis, blood loss, RAS)
Intrinsic (10%): ATN 2* to pre-renal AKI, ACEi, NSAIDs, contrast, rhabdomyolysis, gout, vasculitis, glomerulonephritis, gentamycin, vancomycin, tetracyclines)
Post-renal (20%): obstruction
Drug toxicity: Digoxin
Confusion, nausea, visual halos and arrythmias
Drug toxicity: Lithium
Tremor, tiredness, arrythmias, seizures, coma, RF, DI
Drug toxicity: Phenytoin
Gum hypertrophy, ataxia, nystagmnus, peripheral neuropathy, teratogenicity
Drug toxicity: Gentamicin
Ototoxicity and nephrotoxicity
Drug toxicity: Vancomycin
Ototoxicity and nephrotoxicity
Common drugs requiring monitoring
Digoxin, theophylline, lithium, phenytoin, gentamycin, vancomycin, warfarin, clozapine
Drug causes: thrombocytopenia
Penicillamine (RA, wilson’s)
Heparin
Drug SE: cholestasis
Flucloxacillin, co-amoxiclav, nitrofurantoin, sulphonylureas
Drug SE: AKI
ACEi; NSAIDs; gentamycin, vancomycin, tetracyclines
Drug SE: hypokalaemia
Loop and thiazide diuretics
Drug SE: hyperkalaemia
K sparing diuretics and ACEi
Drug SE: neutropenia
Clozapine
Carbimazole (antithyroid)
Drug interactions: Methotrexate and trimethoprim
Both folate antagonists with risk of bone marrow toxicity, leading to pancytopenia and neutropenic sepsis
Drug interactions: Verapamil and B blockers
Risk of bradycardia and systole and hypotension.
Warfarin: high INR and bleed
Stop warfarin
5-10mg IV vikamin K
Prothrombin complex (e.g. Beriplex)
How to manage high INR in warfarin
<6 reduce warfarin dose
6-8 omit for 2 days then reduce dose
>8 omit and give 1-5mg oral vit K
* If bleeding give 5-10mg IV vit K
What is a common regimen for neutropenic sepsis
IV piperacillin with tazobactam and gentamycin
1st line management of PD
Levodopa + Carbidopa (peripheral dopa decarboxylase inhibitor)
Known as Co-careldopa
Epilepsy 1st line management depending on seizure type and SE
Grand mal - Na Valproate (SE teratogenic, tremor, weight gain)
Absence - Na Valproate
Myoclonic - Na Valproate
Tonic - Na Valproate
Focal - carbamazepine (SE rash, ataxia, nystagmus, hyponatraemia / lamotrigine (SE rash, SJS syndrome)
Phenytoin SE ataxia, peripheral neuropathy, gum hyperplasia, hepatotoxicity
Crohn’s disease - inducing remission
Prednisolone 30mg OD PO
If severe hydrocortisone 100mg QDS IV + supporting care (±rectal roids)
What to check before starting azathioprine?
TMPT (10% population)
RA - treatment
Methotrexate + One DMARD (sulfasalazine or hydroxychloroquine)
Flare: Short term roids IM methylprednisolone 80mg + NSAIDS & PPI
Insomnia on ward
Review meds - e.g. pred should only be given at night
Zopiclone 7.5mg oral nightly in adults (3.75mg nightly in elderly)
Principles of COPD management
- SAMA or SABA PRN
- 1 If FEV1 >50% = LABA / LAMA
- 2 If FEV1 <50% = LABA+ICS / LAMA
- LAMA & ICS+LABA
Management of TIIDM: general principles
- Education and diet/exercise advice
- CV risk management: Aspirin 75mg and Simvastatin 20-40mg OD
- Annual review of complications: ACR (diabetic nephropathy), Opthal review, HTN
- Metformin 500mg PO with breakfast (but if not overweight gliclazdie 40mg with breakfast)
- Increase to max tolerated dose
- Add gliclazide or if already on gliptin (DPP-4i e.g. sitagliptin)
- Insulin
Principles of asthma management
- SABA PRN
- ICS 200-800 ug/d
- LABA (and assess for response, if none increase ICS to 800, if still poor ?leukotriene antagonist or SR theophylline)
- ICS to max of 2mg/d ± oral B agonist / theophylline / leukotriene r antagonist
- Oral steroid in lowest effective form (specialist)
CHA2DS2Vasc score
CCF HTN Age >75 (2pnt) DM Stroke/TIA Hx (2pnt) Vascular disease (IHD/PVD) Age 65-75 Sex (F) If 0 = aspirin 75mg If 1 = aspirin / warfarin INR 2-3 If 2+ = warfarin INR 2-3
AF rhythm control - why and how?
Young / symptomatic / first episode / due to treated precipitant (e.g. sepsis or electrolyte)
Cardioversion - DC or pharmacological (amiodarone 5mg/kg IV over 20-120 min + anticoagulation
AF rate control - why and how?
Everyone not for rhythm control with HR >90
- B block or CCB (e.g. diltiazem 120 mg OD) Verapamil + B block = brady
- If CI or needed, add digoxin. Load then start 62.5-125 ug/d
Principles of management of stable angina
- GTN spray PRN; RF modification
- Depending on CI either BB or CCB (amlodipine/diltiazem)
- Increase as tolerated
- Add other from 2. or if CI long acting nitrate (isosorbide mononitrate) or K channel activator e.g. nicorandil
- PCI / CABG
Principles of management: HTN
Ambulatory / at home BP measurements to confirm
Treat if >150/95 or if 135/85 when IDH, PVD, CRD
Target <140/85 or <135/85 at home
1. ACEi if <55. If black or >55 use CCB
2. Add other
3. Add thiazide
4. Alpha or beta block or further diuretic. Expert advice
Principles of management: chronic HF
ACEi (e.g. lisinopril 2.5mg OD + B blocker (e.g. bisoprolol 1.25mg OD)
Increase as tolerated
Add ARB (if mild); Add hydralazine 25mg TDS and isosorbide mononitrate 20mg 8 hourly if black; Add spronolactone / epleranone in other pts
Principles of management: STEMI
ABCDE + 15L O2 Aspirin 300mg PO Morphine 10mg IV + Metoclopramide 10mg IV GTN spray / tablet PCI B block CCU
Principles of management: NSTEMI
ABCDE + 15L O2
Aspirin 300mg PO
Morphine 10mg IV + Metoclopramide 10mg IV
GTN spray / tablet
Clopidogrel 300mg PO and LMWH (e.g. enoxaparin 1mg/kg bd SC)
B block
CCU
Principles of management: LVF
ABCDE + 15L O2
Aspirin 300mg PO
Morphine 10mg IV + Metoclopramide 10mg IV
GTN spray / tablet
Furosemide 40-80mg IV
If inadequate response isosorbide denigrate infusion ± CPAP
CCU
Principles of management: Anaphylaxis
ABCDE + 15L O2 Remove cause (e.g. blood transfusion) Adrenaline 500ug 1:1000 IM Chlorphenamine 10mg IV Hydrocortisone 200mg IV If wheeze Tx as for asthma) Drug chart allergies box
Principles of management: GI bleeding
ABCDE + 15L O2 IV access + catheter Colloid (gelofuscine) CX 6 units Stop NSAIDs, aspirin, warfarin, heparin Correct clotting abnormalities Endoscopy
Osmolality equation
2 x (Na + K) + urea + glucose
Managing constipation
- Stool softener: docusate sodium, arachis oil PR (CI nut allergy). For faecal impaction
- Bulking agent: isphagula husk. CI stool impaction, colonic atony. Works over days
- Stimulant: Senna / bisacodyl. CI acute abdomen, exacerbates cramps
- Osmotic: Lactulose, phosphate enema. CI acute abdomen, exacerbates bloating
Methotrexate - route, frequency and monitoring
Non non oncological reasons 1 a week.
If more regular = risk of neutropenia and other SE
Folic acid co-prescribed
Initially monitor 1-2 weekly until stable
Warfarin colouring
White = 0.5mg Brown = 1mg Blue = 3mg Pink = 5mg
What should be started alongside oral steroids >3mo
Bisphosphonates (bone protection), esp try in elderly
What does 1% mean (e.g. 1% lignocaine)
1g in 100ml (or 10mg/ml) for weight:volume
1g in 100g for weight:weight
Drug SE: ACEi
Hypotension, electrolyte, AKI, dry cough
Drug SE: BB
Hypotension, bradycardia, Ex Asthma, worsen AHF (but good for CHF)
Drug SE: CCB
Hypotension, bradycardia, peripheral oedema, flushing
Drug SE: Heparin
Haemorrhage (esp RF or <50kg), heparin induced thrombocytopenia
Why must warfarin be co-prescribed with heparin?
Targets fit K dépendant factors. Initially lowers protein C and S therefore procoagulant in first few days. Cover with LMWH until INR >2
What is the relationship between digoxin and K
Competes with K at myocyte Na/K/ATPase, limiting Na influx. Since Ca outflow relies on Na inflow = ++ Ca in cells = lengthens AP and slows HR.
Low K augments digoxin effect; high K limits effect
Drug SE: amiodarone
IPF, thyroid disease (both hyper and hypo, chemically similar to iodine hence amIODarone), skin greying, corneal deposits.
Drug SE: simvastatin
Myalgia, abdo pain, increased ALT/AST, rhabdomyolysis (measure CK)
Drugs with potent interaction with alcohol
GI bleeding: NSAIDS
Increased anticoagulation: warfarin (acute alcohol, chronic = pro coagulation)
Sweating, flushing, N&V (bad hangover): metronidazole and disulfiram
Sedation: barbituates, opiods, benzos
Lactic acidosis: metformin
Hypertensive crisis: MOA inhibitors
What is a common precipitant of gout?
Bendroflumethizide and other thiazide diuretics
What to give for acute dystonia
SE typical antipsychotics - procyclidine
Will act against antiDa effects on basal ganglia