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