Maxigesic Oral Suspension for Children undergoing Tonsillectomy

INTERVENTION: Maxigesic oral suspension: paracetamol 160mg + ibuprofen 48mg / 5 mL a) Corresponding doses: low dose: paracetamol 12mg/kg + ibuprofen 3.6 mg/kg; b) The frequency and duration of administration: 4‐6 hourly for 2 days post surgery c) the mode of administration, oral suspension d) Strategies used to monitor the compliance: IPs will be returned and documented in the accountability Log CONDITION: Post Tonsillectomy Pain Relief PRIMARY OUTCOME: Study Period 1: To characterize the pharmacokinetic profile of two different dose regimes of a fixed dose paracetamol and ibuprofen combination (Maxigesic oral suspension) in children between 2‐12 years of age inclusive by performing the plasma assay (blood samples will be taken during the first 6hrs after the loading dose). ; Study Period 2: To measure pain scores on swallowing using the PPPM's rating on the first post‐operative day and to compare the time adjusted Area under the Curves (AUCt)for the two doses of Maxigesic oral suspension after the first dose on postoperative day one until the midnight dose. SECONDARY OUTCOME: Study Period 1: To assess the PK equivalence of individual components administered in the Maxigesic oral suspension combination to single agent therapy PK data in children from the literature. PK profile analysis of the individual components in Maxigesic oral suspension will be performed through the plasma assay. Blood samples will be taken at the time points listed below: ; 1. Approximately 30 mins after the loading dose ; 2. Immediately before leaving the operating room ; 3. 1 hour after the loading dose ; 4. 2 hour after the loading dose ; 5. 3‐4 hours after the loading dose ; 6. 5‐6 hours after the loading dose ; ; Study Period 2: To compare the amount of rescue medication administered from the first dose on postoperative day one for up to the night‐time dose between the two study groups ‐the consumption of rescue medication will be documented on the participant diary in a self‐management style Study Period 2: To compare the percentage of participants requiring rescue medication on postoperative day one between the two study groups Study Period 2: To compare the time to the first request for rescue medication after the first dose of study medication on post‐operative day one between the two study groups Study Period 2: To measure and compare pain scores on the first post‐operative day by comparison of time‐adjusted AUCt of Wong‐Baker Faces Scales after the first dose on postoperative day one until the night time dose prior to and on swallowing for two doses of Maxigesic oral suspension in the subgroup of older children aged 7‐12 years of age Study Period 2: To measure pain scores prior to swallowing using the PPPM's rating on the first post‐operative day and to compare the time adjusted Area under the Curves (AUCt)for the two doses of Maxigesic oral suspension after the first dose on postoperative day one until the midnight dose. INCLUSION CRITERIA: Children aged 2‐12 yrs of age Scheduled to undergo tonsillectomy with or without adenoidectomy Written informed consent from parents/legal guardians and assent from participant (where appropriate).