The effect of clonidine on pain post-tonsillectomy in children

The study will be a randomized, double-blinded and placebo-controlled study. Following approval from the treating anaesthetist and voluntary written informed consent by the parent/guardian, the recruited children will be block randomised and assigned to one of the two groups, in a 1:1 ratio to receive either clonidine (10mcg/ml) suspension or placebo suspension.The blinding of the drug will be performed by the Clinical Trials Pharmacy who will provide us with the unblinding folders/envelopes for the study. Participants, research assistants, nurses and doctors will be blinded to the allocation. Patients will receive 3mcg/kg (max 150 mcg) of their assigned suspension (rounded to the nearest 0.1 ml) for their first perioperative dose, 30-45 minutes prior to surgery induction. Subsequently, on days 0, 1, 2, 3, 4 and 5 they will receive 1 mcg/kg (0.1 ml/kg, max 50mcg) of their assigned suspension in the morning and at 2pm by mouth, and 2mcg/kg (0.2 ml/kg, max 100 mcg) at night by mouth. Then on days 6 and 7 they will receive 0.5mcg/kg (0.05ml/kg) in the morning and 1mcg/kg (0.1ml/kg) at night. Participants will receive enough doses day 0 (day of surgery) – day 7. The study medications are in addition to the standard medications normally prescribed post tonsillectomy.In the absence of allergies or adverse drug reactions or contraindication, all patients will be prescribed a weight-based regimen of QID paracetamol (15mg/kg) and TDS ibuprofen (10mg/kg) for 7 days postoperatively. Oxycodone (6-hourly PRN) will be also prescribed to all patients. All patients will be given a ‘test dose’ of oxycodone while in hospital to demonstrate its safety to parents and asses patient tolerance. Children without additional risk factors for opioid-related complications will receive oxycodone at 0.1mg/kg of ideal body weight according to our institutional guidelines. Ten-to fifteen doses of oxycodone (1mg/ml syrup) will be dispensed on discharge (up to maximum of 50mls) if patients maintain their oxygen saturation >92% on room air and without excessive sedation following the test dose. The clinical team on review of test dosing may then decide to use a lower oxycodone dose of 0.05mg/kg or avoid this entirely. Four ondansetron 4mg wafers will also be dispensed for use on the first two mornings and then as required as per usual discharge protocol. The patient receiving clonidine/placebo will have tolerated it for at least 3 doses in hospital prior to discharge without any adverse event attributable to the medication being observed. There will be active follow up with the families to ensure study adherence. All families are provided with a standard diary to document medication administration following tonsillectomy surgery. Our families will also be provided with a study diary where they will document further information. They will also report this in the study database via survey links sent daily. After the recruitment of the first 50 patients there will be a review of the postoperative CO2 and Spo2, mean heart rates and mean blood pressure during the first postoperative night.