Rectal versus intravenous administration of acetaminophen; Clinical investigation of plasma level, analgesic, and antipyretic effects on 6-month to 6-year-old children in Zabol city, Iran.

ABSTRACT

OBJECTIVES: Acetaminophen is the most widely antipyretic analgesic medicine used in adults and children worldwide. Rectal acetaminophen is widely used in children who resist or cannot take oral medications. This study was designed to compare the efficacy of rectal and IV acetaminophen in children with fever and mild to moderate pain. PATIENTS AND METHODS: Total 60 children aged six months to 6 years, with fever and pain, that were treated with rectal or intravenous acetaminophen were selected and assigned in two groups. The IV group received 10mg/kg paracetamol as an IV infusion, and the rectal group received a 15mg/kg dose immediately after admission. Pain score was calculated using the FLACC method, and the axillary temperature was recorded at baseline and then 0.5, 1, 2, 4, and 6hours after drug administration. Blood samples were collected at baseline and then at 30min-intervals for the first 90minutes. RESULTS: The trend of changes in mean pain score at different time intervals was significantly different between the two groups. Body temperature decrease was more prominent in the IV group. The plasma concentration increased in both groups significantly with time. This increase was sharper in the IV group, just in the first 60minutes after drug administration. CONCLUSIONS: IV acetaminophen has more rapid onset of action, while rectal dosage form control fever and pain for longer duration. Considering its favorable effects with ease of administration and lower cost, rectal acetaminophen can be a reasonable option in selected patients with pain or fever.