Use of nonopioid analgesics in children

Posted by Piscean on


Use of nonopioid analgesics in children
Caution should be exercised in determining all drug doses in children. The most common error is to get the decimal point wrong and be out by a factor of 10.

Paracetamol is one of the commonest analgesics used in children. It is absorbed after oral administration within 30 minutes, and can be used pre-emptively for minor surgery, procedures or vaccination. It is slowly absorbed after rectal administration, and peak blood concentrations may not be reached for up to 90 minutes. An intravenous form of paracetamol (10 mg/mL) is now available for hospital use in Australia, is given over 15 minutes, and is approved for use in children.

Paracetamol can be used with appropriate doses of opioids or nonsteroidal anti-inflammatory drugs (NSAIDs) for greater analgesia. Use of paracetamol after surgery can reduce opioid requirements by 15% to 20%. Paracetamol is safe and effective for use in asthmatics.

There are many different commercially available preparations. Paracetamol is also present in many nonprescription combination preparations for colds and pain relief. Compound analgesics preparations can reduce the scope for effective titration of individual components.

Care should be taken to avoid overdosage.
The risk of paracetamol toxicity is increased by the concurrent use of multiple formulations that contain paracetamol, and also by prolonged use, particularly in children who are febrile and dehydrated.
Inadequate pain relief or persistent pain may require medical review.
In obese children, the dosage given should be based on ideal body weight, which can be estimated as the 50th centile on an appropriate weight-for-age percentile chart. 

Nonsteroidal anti-inflammatory drugs (NSAIDs) are very effective for mild to moderate pain in children. They can also be used in conjunction with paracetamol and opioids such as codeine and morphine. NSAIDs have a significant opioid-sparing effect, and lower opioid doses will reduce the incidence of opioid-related adverse effects such as sedation, respiratory depression, emesis, reduced gut motility, and urinary retention.

Adequate hydration is required in the postoperative period. Consequently, after major surgery, oral NSAIDs are usually only started once the child is eating and drinking adequately, and they are prescribed for a set time period (eg three days).

Short-term use of ibuprofen appears to be safe in patients with mild asthma. Caution may be required if NSAIDs are used for analgesia for procedures such as adenotonsillectomy, where there is potential for significant postoperative bleeding.

Contraindications to the use of NSAIDs in children include:
  • known hypersensitivity or allergy to aspirin or NSAIDs
  • peptic ulcer disease
  • bleeding diatheses, or potential for bleeding postoperatively
  • severe asthma, especially if aspirin-sensitive or corticosteroid-dependent
  • nasal polypitis
  • renal dysfunction, hypovolaemia, diuretic therapy
  • planned major surgery.
The value of selective inhibitors of COX-2 (such as celecoxib) for analgesia in children is not yet clear.

Aspirin is not commonly used as an analgesic in children due to its association with Reye’s syndrome. It may occasionally be used in juvenile arthritis. Very low doses (2 to 5 mg/kg/day) can be used for antiplatelet effects (eg with cyanotic congenital heart disease).

Comments

Post a Comment