Codeine (Dosage)

Codeine is an opioid derivative widely used as an analgesic, sedative and antitussive. It is metabolized through the CYP2D6 cytochrome, so knowing the presence of certain alleles can help to better adjust the dose.

Codeine is an opioid drug with central antitussive effect, analgesic, sedative effect and antidiarrheal effect.

Codeine is useful for treating moderate to severe pain.


Hypersensitivity to codeine or derivatives.

Codeine is contraindicated in patients with OPD (Obstructive Pulmonary Disease), with acute attacks of asthma or with respiratory depression.

Contraindicated in patients with paralytic ileus or at risk, in patients with diarrhea associated with pseudomembranous colitis caused by cephalosporins, lincomycins or penicillins, also contraindicated in patients with diarrhea caused by poisoning until the toxic material has been removed from the gastrointestinal tract.

Contraindicated treatment in children under 12 years old and in those under 18 years old who are going to be operated on for tonsillectomy / adenoidectomy due to obstructive sleep apnea syndrome, due to the increased risk of presenting serious adverse reactions. Caution in patients that are ultrarapid cytochrome CYP2D6 metabolizers.

Codeine presents risks, although infrequent, during lactation.


Precaution should be exercised when prescribing codeine in the elderly.

Caution in patients with impaired hepatic, renal or cardiac function, prostatic hypertrophy, urethral stenosis, adrenal insufficiency (Addison's disease), obstructive or inflammatory bowel disorders, hypothyroidism, multiple sclerosis, chronic ulcerative colitis, gallbladder disease and diseases that cursen with decreased respiratory capacity and seizure disorders.

In prolonged treatments with codeine there is a risk of physical dependence and tolerance, which requires a gradual suspension of treatment when it is no longer needed.

Codeine can mask the clinical course of a traumatic brain injury and make difficult the diagnosis or clinical evolution of acute abdominal processes.

It is not recommended in children in whom there may be a compromise of respiration such as neuromuscular disorders, respiratory or severe cardiac pathology, pulmonary or upper respiratory tract infections, multiple trauma or those that have undergone extensive surgical procedures.


The appearance of constipation limits its chronic use, therefore it is advisable to associate a stimulating laxative together with a good hydration.

Dizziness, drowsiness, convulsions, nausea, vomiting, pruritus, rashes in allergic patients, mental confusion, euphoria, dysphoria.

At high doses of codeine: respiratory, thoracic, mediastinal, and respiratory depression, so respiratory physiotherapy is usually advised to eliminate secretions.


Codeine may have its analgesic effect diminished if it is prescribed concomitantly with morphine agonist-antagonists (nalbuphine, naltrexone, buprenorphine, pentazocine).

The excitability of the patient is increased when taking codeine concomitantly with MAOI antidepressants and tricyclic antidepressants.

Codeine produces potentiation of central depression in concomitancy with antidepressants, sedatives, antihistamines H1 sedatives, anxiolytics, neuroleptic hypnotics, clonidine and related, thalidomide, narcotic analgesics, antipsychotics, neuromuscular blockers, hydroxyzine, alcohol.

There is a greater risk of respiratory depression if codeine is taken along with other morphine analgesics, barbiturates and benzodiazepines.

There is a risk of paralytic ileus and /or urinary retention if codeine is prescribed together with anticholinergic drugs.

Constipation and intestinal obstruction risk exists if codeine is taken in concomitance with antiperistaltics.

Codeine increases the action of some analgesics.

The action of codeine is increased by cimetidine, quinidine and fluoxetine.


  • Bisoltus ®
  • Codeisan ®
  • Fludan codeina ®
  • Histaverin ®
  • Notusin ®
  • Perduretas Codeína ®
  • Toseína ®

Genes analyzed



Crews KR, Monte AA, Huddart R, et al.Clinical Pharmacogenetics Implementation Consortium Guideline for CYP2D6, OPRM1, and COMT Genotypes and Select Opioid Therapy. Clin Pharmacol Ther. 2021 Oct;110(4):888-896.

Crews KR, Gaedigk A, Dunnenberger HM, et al.Clinical Pharmacogenetics Implementation Consortium guidelines for cytochrome P450 2D6 genotype and codeine therapy: 2014 update. Clin Pharmacol Ther. 2014 Apr;95(4):376-82.

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