Sir, I was somewhat surprised to read the letter A single dose (BDJ 2008; 205: 525), in which the author routinely prescribed a single dose of metronidazole 200 mg post-operatively for the prevention of dry socket.

A recent literature review on dry socket by Noroozi et al.1 states the incidence of dry socket for a young, healthy and non-smoking young male to carry a 1-4% risk. Risk factors such as traumatic extractions, age, gender and mandibular teeth were also highlighted. Noroozi identified that antimicrobials can help to prevent dry socket, of which metronidazole was shown to have the greatest effect, but only if taken pre-operatively. The use of systemic antimicrobials was also only recommended for the immunocompromised patient.

NICE guidelines published October 20082 for the prevention of post surgical infection state that antibiotic prophylaxis should not be used routinely for clean non-prosthetic surgery. If antibiotics were indicated, then a single dose preoperatively, or intravenously at the time of starting the procedure, should be considered. The use of post-operative antibiotics is only indicated when surgical site infection is suspected.

In a time where we are seeing incidences of antimicrobial drug resistance, prudent prescribing of antimicrobials by healthcare professionals is essential. I therefore feel that this particular prescribing could only be regarded as not only ineffective, but inappropriate.