Drug utilization evaluation of i.v. paracetamol at a large teaching hospital

I.v. paracetamol has recently become available in Australia for the treatment of pain when the oral or rectal administration route is not accessible. Our primary aim was to assess compliance with prescribing guidelines and our secondary aim to evaluate the safety of i.v. paracetamol use (4 g/day) and the effect of patient comorbidities on drug safety.

Eighty-five consecutive patients were identified through the pharmacy dispensing system at a 900-bed, metropolitan, primary care and tertiary referral hospital over a period of 7 months from December 2005 to June 2006. Cross-sectional evaluation by patient interview, review of medical records and pathology parameters were carried out. The study has been approved by the Royal Brisbane and Women's Hospital Human Research Ethics Committee.

I.v. paracetamol was given for pain following abdominal surgery (90%) and musculoskeletal pain (10%). The comorbid conditions included severe renal impairment (9.4%), alcohol dependence (3.5%), pre-existing liver failure (2.4%) and malnutrition (18.8%). Prescribing guidelines were not adhered to in 25% of patients. The main cause for discordance observed in 90% of this group was the administration of i.v. paracetamol despite the presence of an alternative route of administration. Eight patients received i.v. paracetamol despite not having had a surgical procedure. Twelve patients received i.v. paracetamol for longer than 48 h; no injection site reactions or toxicity were noted.

A lack of concordance between i.v. paracetamol use and prescribing guidelines was identified. There were no new safety concerns.