Should Codeine, Dextromethorphan or Hydrocodone be Prescribed?
AAP Committee on Drugs, Pediatrics June 1997
Introduction: Pediatricians often feel that they need to prescribe something when a patient comes to the office. Of course, the primary cause of cough - if present - needs to be identified and treated: eg allergy, GE Reflux, asthma, irritants such as cigarette smoke, dust and wood heat. Even if one of these etiologies is found, codeine, dextromethorphan, hydrocodone are often prescribed to give symptomatic treatment to children. What will you recommend when you are in private practice?
1. Codeine
Mechanism of action: suppress artificially and disease-related cough through CNS action
Dosage usually used: 1 mg/kg/day in 4 divided doses up to 60 mg/day.
Side Effects: respiratory depression and obtundation; can be addictive.
< 2 mg/kg/day: unlikely to have any side effects
3-5 mg/kg/day: somnolence, ataxia, miosis, vomiting, rash, facial swelling, itching
> 5 mg/kg/day: 3% require mechanical ventilation; 2 deaths.
Interactions with other medications: If given with Acetaminophen, increased toxicity:
Hepatic glucuronidation pathway incompletely developed in infants putting infants at increased risk, more if given with other meds metabolized in the liver.
Evidence of effectiveness: shown to definitely work in the chronic cough of adults; a linear relationship between the dose and the frequency of chronic cough. There is no study that shows that codeine is effective in suppressing cough in children: Ref: Taylor: JPeds 93;122:799-802. Controlled study: same as placebo.
2. Dextromethorphan
Mechanism of action: same as codeine; in adults’ works through CNS action to elevate the threshold for coughing.
Dosage used: also 1 mg/kg/day in 3 to 4 divided doses.
Side Effects: behavioral disturbances including respiratory depression
Evidence of effectiveness: same study of Taylor: no difference from placebo.
3. Hydrocodone and hydromorphone
More addictive than codeine and should not be used. Elixir contains 25% alcohol.
4. Combination Medications: antihistamines, decongestants, expectorants, and antipyretics and codeine or dextromethorphan.
Problem: these medications are potentially harmful particularly in children less than 6 mos of age. Immature hepatic enzyme systems make side effects from decongestants more likely: irritability, restlessness, lethargy, hallucination, hypertension, and dystonia.
Dosage: never worked out well so that dosages extrapolated from adult data.
Conclusions of AAP Committee on Drugs about cough medications in children:
No studies support efficacy and safety of narcotics.
No clear-cut indications in children. Cough suppression may be hazardous and contraindicated in some illnesses.
Dosage guidelines for cough and cold mixtures are imprecise for children.
Parents must be educated about lack of proven effect and risks of medications.
Medical College of Georgia
Department of Pediatrics | Medical College of Georgia
http://www.mcg.edu/pediatrics/CCNotebook/chapter2/cough.htm