Principles of Prescribing

Question 1

What must every drug prescription be?

Answer 1

1. Legible
2. Unambiguous
3. Using an approved name (tacrolimus must be prescribed with the brand name)
4. IN CAPITALS
5. Signed
6. Indication and maximum frequency (If PRN) or stop/review date for antibiotics.
7. Have a specified treatment duration.

Question 2

Which enzymes metabolise most drugs?

Answer 2

Cytochrome P450 (Hepatic)

Question 3

What do enzyme (CYP450) inducers do?

Answer 3

Reduce effect

Question 4

What do enzyme (CYP450) inhibitors do?

Answer 4

Increase effect

Question 5

Common Enzyme Inducers

(PCBRAS)

Answer 5

Phenytoin, Carbamzepine, Barbituates, Rifampicin, Alcohol (Excess), Sulphonylureas

Question 6

Enzyme Inhibitors

(AODEVICES)

Answer 6

Allopurinol, Omeprazole, Disulfiram, Erythromycin, Valproate, Isoniazid, Ciprofloxacin, Ethanol (Acute), Sulphonamides

Question 7

Drugs to Stop Before Surgery

(ILACKP)

Answer 7

Insulin and Oral Hypoglycaemics
Lithium (Day Before)
Anticoagulants/Antiplatelets
COCP/HRT
K Sparing Diuretics (Day of Surgery)
Perindopril (ACEi) (Day of Surgery)

Question 8

Peri-operative Steroids

Answer 8

Steroids should be given at anaesthetic induction to avoid adrenal crisis.

Similar to IV Hydrocortisone when steroid patients are unwell.

Question 9

How are Topical Creams Dosed?

Answer 9

**Fingertip Units (FTU) **
* Enough cream to reach a line from the tip to first finger crease (Enough to cover both sides of the hands)