2. Prescription Review Flashcards
What effect does P450 induction/inhibition have on drug action?
Inducers decrease
Inhibitors increase
What are the common enzyme inducers?
PC BRAS
Phenytoin
Carbamazepine
Barbiturates
Rifampicin
Alcohol
Sulphonylurea
Speeds up P450 action so decrease drug concentration
What are the common enzyme inhibitors?
AO DEVICES
Allopurinol
Omeprazole
Disulfram
Erythromycin
Valproate
Isoniazid
Ciprofloxacin
Ethanol
Sulphonamides
What drug should be prolonged for surgery?
Steroids
What drugs should be stopped for surgery?
I LACK OP
Insulin
Lithium
Anticoagulants/anti-platelets
COCP
K-sparing and ACEIs
Oral hypoglycaemics
Perindopril/other ACEis
When should the COCP be stopped for surgery?
4 weeks prior
When should Lithium be stopped before surgery?
Day before
When should potassium-sparing diuretics and ACEIs be stopped?
Day OF surgery
How is metformin modified for surgery
Take normally < 3x daily <= omit lunchtime
How are the following insulin regimes altered for surgery?
Lantus
Novomix/humulin
Lantus: Reduce by 20% day before
Novomix/humulin: Half morning, evening unchanged
How do you alter insulin if >1 meal or <60eGFR?
Sliding scale
When should NOACs be stopped surgery?
~2 days before
When should prophylactic rivaroxaban be stopped before surgery?
18 hours
What are the essential items to consider when prescribing drugs
PReSCRIBER
Patient details
Reaction (allergy with details)
Sign the front of chart
Contraindications
Route
IV fluids
Blood clot prophylaxis
anti-Emesis
pain Relief
What two groups of people are contraindicated for anti-coagulation?
Increased risk of bleeding
Enzyme inhibitors
What are the side-effects of Steroids
Stomach ulcers
Thin Skin
Edema
Right/Left heart failure
Osteoporosis
Infections (inc candida)
Diabetes
Syndrome of cushing’s
What are the cautions and contraindications of NSAIDs?
No urine (renal failure)
Systolic dysfunction (heart failure)
Asthma
Indigestion (any cause)
Dyscrasia (clotting abnormality)
For antihypertensives, list the…
Broad
Mechanistic
Broad: Hypotension
Mechanistic:
- B-blockers, nd-CCBs: bradycardia
- Electrolyte imbalances: ACEIs, diuretics
What are the individual side effects of the following anti-HTN meds:
- ACEIs
- BBs
- CCBs
- Diuretics
ACEIs: Arid (dry) cough
BBs: Breath sounds (wheezy asthma), bat wings (worsens acute HF)
CCBs: Calf oedema, crimson skin (flushed)
Diuretics: DIE NEPHRONS (renal failure)
+ Loops: Lumpy toes (gout)
+ K+-sparing: gyno-K+-mastia
For fluid replacement, when is 0.9% NaCl NOT given?
Bleeding: Blood transfusion
Ascites: Human Albumin solution
Shocked (BP<90mmHg): Colloid
HYPERnatraemic/hypoglycaemic: 5% dextrose
How fast should you replace fluids?
Depends on affected obs
Tachy/low BP: 500ml (250ml if heart failure) ASAP
Oliguric (non-obstructive): 1L over 2-4hrs
Rough guides
Oliguria (<30ml/h): 500ml
Oliguria + tachy: 1L
Oliguria + tachy + shock: 2L
Regarding maintenance fluids, what is the requirement for
- Volume of fluids
- Electrolytes
Adults need 3L/24hrs, elderly need 2L/24 hours
1L 0.9% NaCl and 2L 5% dextrose (1 salty, 2 sweet)
How fast should you give maintenance fluids?
3L: 8-hourly bags
2l: 12 hourly bags
What is the standard VTE prophylaxis?
5000 units dalteparin OR NOAC
VTE stockings
