Prescription error

Clinical Pharmacology and Toxicology

Look at the following sample prescription (you may use your BNF for this question)

Mr Pan has been bitten by a dog and his family doctor is a little concerned. Having cleaned the wound he gives a course of antibiotics.

Patient ID
Mr Peter Pan
1/1/391
Boat Street
Fairlyand

Hospital no:234567
Special InstructionsAllergies

Penicillin
Name
CO-AMOXICLAV

Route
Oral

Frequecy
QDS
Dose

625 mg

Comments
Time given

0800
1200
1800
2200

What is the most important error on this prescription?

  • Incorrect route
  • Incorrrect dose
  • Incorrect frequency
  • Coamoxiclav is not indicated for this condition
  • Contraindicated drug

Dose etc. are all correct.

The trick here is the penicillin allergy which means Penicillin and its derivatives are all essentially contraindicated until a further allergy history is taken.

Cephalosporins also have a cross reactivity in penicillin allerygy that may approach 10%. Therefore for exam purposes I would also consider these drugs contraindicated (e.g. cefuroxime).

For exam purposes in these instances senior support or microbiological advice is often suggested if no alternative is obvious.

Although co-amoxiclav is normally given 3 times a day, 4 times a day is still within a reasonable dose range.