It is often helpful to warn patients and their families about the commoner adverse effects (constipation, nausea and vomiting, lethargy) so that their occurrence does not lead to loss of confidence in the medication.

• Constipation:  Common and unpleasant, laxatives (Movicol or Senna and Magnesium sulphate, not lactulose) should always be prescribed.
• Nausea and vomiting:  Occurs less commonly than in adults and usually settles in 3-4 days.  In the interim anti-emetics should be prescribed for use as needed (see nausea and vomiting guideline).
• Lethargy:  Often occurs when opioids are first started but wears off in 48hrs.
• Urinary retention:  May be more common in children than adults.  Carbachol or bethanechol can be useful.
• Pruritis may also be more common in children:  Treating with calamine lotion or hydrocortisone may be useful.
• Nightmares are occasionally reported.
• Physical dependence:  Unlikely to occur in a palliative setting but opioids should be weaned and not ceased abruptly.
• Tolerance:  commonly occurs and should be managed by increasing the dose in a controlled fashion, or rotating to an alternative opioid if side effects limit further increase.
• Respiratory depression:  much feared but grossly overestimated.  Pain is an effective stimulant and apnoea is highly unlikely if appropriate titration is carried out.