The new Guidelines have a more cautious approach and replace the dosage recommendations in the WHO Model Formulary for Children (2012).
In view of these new Guidelines the dosage recommendations for morphine and other opioid analgesics in children in future editions of other relevant publications (text books, hand books etc.) may need to be reconsidered. WHO has not recently published guidelines on the use of opioid analgesics in adults, but the following may also apply to their prescription to adults:
Pain treatment with strong opioids should be based on a low initial dosing. (See tables 1 to 3 for paediatric starting dosages.) Titration of the dosage should be based on a regular assessment of the pain level. This assessment is discussed in the Guidelines. After a starting dose according to the Guidelines, the dosage should be adjusted to the level that is effective (with no ceiling or maximum dose), but the maximum dosage increase is 50% per 24 hours in outpatient settings. Experienced prescribers can increase up to 100% with close monitoring of the patient, increasing to the level that is effective. The preferred route is oral. If oral administration is not possible, subcutaneous administration or other parenteral routes can be considered, but intramuscular administration should be avoided as it is painful. It should be noted that, due to the first pass effect, parenteral administration is about twice as potent as oral administration.
The dose titration schedule mentioned above also applies to most other strong opioids as well, but not to methadone because of its long half-life. Details for titrating methods for methadone that avoid accumulation can be found in the Guidelines.
In case of overdosage of opioids, the antagonist naloxone can be administered. Occurrence of dependence is often not well understood. On adequate treatment of pain, it is rare, if occurring at all. However, if opioids are withdrawn abruptly in chronic treatment, severe withdrawal symptoms will be precipitated. Therefore, when stopping treatment, the patient should be weaned gradually: after short-term therapy (7–14 days), the dose can be decreased by 10–20% of the original dose every 8 hours, increasing gradually the time interval between doses. After long-term therapy, the dose should be reduced not more than 10–20% per week.
Pharmacological profiles for morphine and several other opioid and non-opioid analgesics, as well as for the antagonist naloxone can be found in Annex 1 of the Guidelines (page 63). The Guidelines can be downloaded from the web free of charge.
The printed Guidelines package contains also a pocket dosing card and pain assessment scales for children. The new Guidelines can be downloaded from the WHO website. Go to: http://www.who.int/medicines/areas/quality_safety/guide_perspainchild/en/index.html
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