Opioids and acute pain medicines — branching viva

I would stop the codeine immediately. Codeine is contraindicated in children under 12 years and for postoperative pain after tonsillectomy or adenoidectomy in children under 18 years. [1] [2] This child sits squarely in both contraindicated groups: he is four years old and he has just had a tonsillectomy. I would replace it with a safe modern regimen — scheduled paracetamol and ibuprofen, with oral morphine or oxycodone as rescue — and because he has obstructive sleep apnoea I would monitor him overnight with continuous oximetry, use the smallest effective opioid dose, and avoid any background infusion. [6] [9]

Codeine is a prodrug with little analgesic activity of its own. About 5 to 10 per cent of a dose is converted by the cytochrome P450 2D6 enzyme — CYP2D6 — into morphine, and it is the morphine that produces the analgesia. CYP2D6 activity is genetically determined, so the conversion is unpredictable: an ultrarapid metaboliser generates a dangerous excess of morphine from a normal codeine dose, and a poor metaboliser generates almost none. Because you cannot tell an ultrarapid metaboliser at the bedside, every child carries the risk. Tramadol is contraindicated for the same reason — CYP2D6 converts it to the active O-desmethyltramadol. [2] [3]

A series of deaths from respiratory depression in young children, many of them CYP2D6 ultrarapid metabolisers, following tonsillectomy or adenoidectomy for obstructive sleep apnoea. These children were exactly this child — young, airway-sensitive, and given codeine after their airway surgery. The United States Food and Drug Administration issued a boxed warning, and the United Kingdom and European regulators issued contraindications. The risk was judged unacceptable because safer alternatives exist. [1] [2]

For severe acute pain I would give intravenous morphine 0.1 to 0.2 milligram per kilogram titrated slowly in increments — for a 16-kilogram child that is 1.6 to 3.2 milligrams — reassessing after each increment until the pain is controlled. For ongoing pain I would use either oral morphine 0.2 to 0.5 milligram per kilogram every four hours or, if intravenous analgesia is needed, a morphine infusion at 10 to 40 microgram per kilogram per hour. Given his age and the obstructive sleep apnoea, I would start at the lower end, monitor continuously, and avoid a background infusion in this opioid-naive child. I would also prescribe a prophylactic stimulant laxative from the first dose, because opioid constipation is near-universal. [6] [9]

He has opioid-induced respiratory depression. The earliest sign is a reduction in the depth and then the rate of breathing with rising sedation — which is exactly what the nurse is describing — and oxygen saturation falls late. My first moves are to stimulate him, open and support his airway, and provide bag-valve-mask ventilation if his breathing is inadequate, then give naloxone titrated to his respiratory rate rather than to full consciousness. [9]

I would give naloxone 10 microgram per kilogram intravenously — about 160 microgram for a 16-kilogram child — repeated every two to three minutes until his respiratory effort is restored. If I cannot get intravenous access quickly, intramuscular or intranasal naloxone is an option and is rapidly absorbed. The principle of titration is essential: the goal is to restore adequate breathing, not to render him fully awake, because a large naloxone dose precipitates acute opioid withdrawal, uncontrolled pain, and agitation. Because naloxone has a short half-life — about 30 to 80 minutes — and is shorter than morphine, I would observe him for renarcotisation and consider a naloxone infusion if he re-sedates. [11]

Three things. First, codeine and tramadol have no place in paediatric analgesia — the contraindication must live in the prescriber's head, not only in the decision-support software. Second, every opioid regimen needs paired pain and sedation scoring — a rising sedation score is the warning before apnoea, and recording it together is the cheapest, most reliable monitor. Third, the opioid-naive child should never receive a background infusion — bolus with lockout lets the child protect themselves, and naloxone must always be at the bedside. With these habits — the right drug, the right monitoring, no background infusion, and naloxone available — opioids remain effective and necessary for the child in real pain. [9] [10]