Mnemonics

Question 1

What will enzyme inducers do to levels of other drugs?

Answer 1

Will increase CYP450 enzyme activity -> reduced drug concentration

Question 2

Mnemonic to remember enzyme inducers

Answer 2

PC BRAS
- Phenytoin
- Carbamazepine
- Barbiturates
- Rifampicin
- Alcohol (chronic excess)
- Sulphonylureas

Question 3

What will enzyme inhibitors do to levels of other drugs?

Answer 3

Will reduce CYP450 enzyme activity -> increased drug concentration

Question 4

Mnemonic to remember enzyme inhibitors

Answer 4

AO DEVICES
- Allopurinol
- Omeprazole
- Disulfiram
- Erythromycin
- Valproate
- Isoniazid
- Ciprofloxacin
- Ethanol (acute intoxication)
- Sulphonamides

Question 5

Mnemonic to remember which drugs to stop before surgery

Answer 5

I LACK OP:
- Insulin
- Lithium
- Anticoagulants/antiplatelets
- COCP/HRT
- K-sparing diuretics (spironolactone)
- Oral hypoglycaemics
- Perindopril and other ACEi

Question 6

When do you stop the ILACKOP drugs before surgery?

Answer 6

COCP/HRT - 4 weeks before surgery. No alternative sought.
Lithium - day before
K-sparing diuretics and ACEi - day of surgery

Insulin and oral hypoglycaemics - variable.
Metformin is stopped the day before surgery due to the risk of lactic acidosis in the event of renal compromise during surgery.
All diabetics are considered for sliding scale.
Insulin is generally stopped and replaced by a sliding scale in the perioperative period.

Anticoagulants/antiplatelets - variable however no alternative sought.

Question 7

Hypokalaemia causes

Answer 7

DIRE:
- Drugs (loop and thiazide diuretics)
- Inadequate intake/intestinal loss
- Renal tubular acidosis
- Endocrine disorders (Cushing’s and Conn’s)

DIRE is a more depressed feeling = low potassium levels.

Question 8

Hyperkalaemia causes

Answer 8

DREAD:
- Drugs (K+ sparing diuretics and ACEi)
- Renal failure
- Endocrine causes (Addison’s disease)
- Artefact (e.g. a haemolysed sample)
- DKA

DREAD is a higthened state = high potassium levels