Intravenous Paracetamol as an Antipyretic and Analgesic Medication: the Significance of Drug Metabolism

• Published in: Journal of Pharmacological Sciences 2014/02/20, Vol.124(2), pp.144-152
• Main Authors: Giamarellos-Bourboulis, Evangelos J., Spyridaki, Aikaterini, Savva, Athina, Georgitsi, Marianna, Tsaganos, Thomas, Mouktaroudi, Maria, Raftogiannis, Maria, Antonopoulou, Anastasia, Papaziogas, Vassilios, Baziaka, Fotini, Sereti, Kalliopi, Christopoulos, Petros, Marioli, Androniki, Kanni, Theodora, Maravitsa, Panagiota, Pantelidou, Ilianna, Leventogiannis, Konstantinos, Tsiaoussis, Panagiotis, Lymberopoulou, Korina, Koutelidakis, Ioannis M.
• Format: Article
• Language: English
• Subjects: Abdominal Pain - drug therapy; Acetaminophen - administration & dosage; Acetaminophen - blood; Acetaminophen - metabolism; Acetaminophen - pharmacokinetics; Adolescent; Adult; Aged; analgesia; Female; fever; Fever - drug therapy; Fever - etiology; Humans; Infection - complications; Infusions, Intravenous; Interleukin-6 - blood; intravenous paracetamol; Male; Middle Aged; pain; Pain, Intractable - drug therapy; Pain, Postoperative - drug therapy; Prospective Studies; Treatment Outcome; Young Adult
• ISSN: 1347-8613; 1347-8648
• DOI: 10.1254/jphs.13133FP

One prospective, open-label, non-randomized study was conducted in 100 patients to define the antipyretic and analgesic effect of a new intravenous formulation of 1 g of paracetamol; 71 received paracetamol for the management of fever and 29 received paracetamol for pain relief after abdominal surgery or for neoplastic pain. Serial follow-up measurements of core temperature and of pain intensity were done for 6 h. Additional rescue medications were recorded for 5 days. Blood was sampled for the measurement of free paracetamol (APAP) and of glucuronide-APAP and N-sulfate-APAP by an HPLC assay. Defervescence, defined as core temperature below or equal to 37.1°C, was achieved in 52 patients (73.2%) within a median time of 3 h. Patients failing to become afebrile with the first dose of paracetamol became afebrile when administered other agents as rescue medications. Analgesia was achieved in 25 patients (86.4%) within a median time of 2 h. Serum levels of glucuronide-APAP were greater among non-responders to paracetamol. The presented results suggest that the intravenous formulation of paracetamol is clinically effective depending on drug metabolism.