Randomized, controlled, multicentre clinical trial of the antipyretic effect of intravenous paracetamol in patients admitted to hospital with infection.

Aim: No randomized study has been conducted to investigate the use of intravenous paracetamol (acetaminophen, APAP) for the management of fever due to infection. The present study evaluated a new ready-made infusion of paracetamol.

Methods: Eighty patients with a body temperature onset ≥38.5°C in the previous 24 h due to infection were randomized to a single administration of placebo (n = 39) or 1 g paracetamol (n = 41), and their temperature was recorded at standard intervals. Rescue medication with 1 g paracetamol was allowed. Serum samples were collected for the measurement of APAP and its metabolites. The primary endpoint was defervescence, defined as a core temperature ≤37.1°C.

Results: During the first 6 h, defervescence was achieved in 15 (38.5%) patients treated with placebo compared with 33 (80.5%) patients treated with paracetamol 1 g (P < 0.0001). The median time to defervescence with paracetamol 1 g was 3 h. Rescue medication was given to 15 (38.5%) and five (12.2%) patients allocated to placebo and paracetamol, respectively (P = 0.007); nine (60.0%) and two (40.0%) of these patients, respectively, experienced defervescence. No further antipyretic medication was needed for patients becoming afebrile with rescue medication. Serum glucuronide-APAP concentrations were significantly greater in the serum of patients who did not experience defervescence with paracetamol. The efficacy of paracetamol was not affected by serum creatinine. No drug-related adverse events were reported.

Conclusions: The 1 g paracetamol formulation has a rapid and sustainable antipyretic effect on fever due to infection. Its efficacy is dependent on hepatic metabolism.