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Codeine-promethazine syrup evidence profile

Codeine-promethazine syrup combines two active drugs with different metabolism and clinical effects.

Category: opioid-combo · Updated: August 7, 2026

Sources and model notes are maintained by . This page is educational, not clinical guidance. Corrections: admin@halflifedb.co.

Model statusNo curve publishedCurrent sources do not support one defensible human input
Evidence boundarySource note onlyNo animal, forensic, mixture, or proxy value is presented as a human half-life
Model scopeNot modeledThe profile explains what the available records can and cannot establish
References3Linked studies, labels, reviews, or identity records described below

Codeine-promethazine syrup: evidence and interpretation notes

Why HalfLifeDB does not plot Codeine-promethazine syrup

Codeine-promethazine syrup combines two active drugs with different metabolism and clinical effects. A codeine-only three-hour curve under a combination-product name would be incomplete and could be mistaken for a timing guide.

Codeine-promethazine syrup is a combination-product entry, so the displayed half-life cannot represent every active component equally.

The citations include a direct promethazine-codeine label plus compound records for codeine and promethazine.

This page does not discuss preparation, misuse, dosing, respiratory risk, or interactions.

What each source contributes

  • DailyMed: Promethazine hydrochloride and codeine phosphate solution. This product label adds formulation-specific pharmacokinetic context and does not represent every route or product.
  • PubChem: Codeine. This identity record confirms names and compound identity and does not supply a human half-life.
  • PubChem: Promethazine. This identity record confirms names and compound identity and does not supply a human half-life.

For Codeine-promethazine syrup, the decision to withhold a curve turns on the limits visible in DailyMed: Promethazine hydrochloride and codeine phosphate solution. This product label adds formulation-specific pharmacokinetic context, but it does not represent every route or product.

What evidence would change the page

The publication threshold for a future Codeine-promethazine syrup model is concrete: serial human plasma data, explicit analyte identification, a described route or preparation, and a reported half-life phase. DailyMed: Promethazine hydrochloride and codeine phosphate solution remains useful, but it does not cross that threshold.

InterpretationCategory context and evidence limits

opioid combination product context

Combination-product entries can include more than one pharmacokinetic story, so a single displayed curve should be read as the selected analyte model only.

  • Co-formulated ingredients may have different half-lives and risks.
  • The page does not model interaction or combined toxicity.
  • Labels and source notes should be read before comparing values.
EvidenceSource trail and model decision

Sources and evidence context

A linked record is not automatically proof of the displayed value. Study, labeling, review, and compound identity sources serve different purposes; notes below identify limitations when they are known.

0 PubMed0 PMC1 DailyMed2 PubChem
  1. Official labeling DailyMed label: Promethazine hydrochloride and codeine phosphate solution.
    Official U.S. product labeling used for formulation and labeled pharmacokinetic context; its statements apply to the described product.
  2. Identity record PubChem Compound Summary: Codeine.
    Compound identity and naming record. It supplies chemistry context, not independent numerical support for the model.
  3. Identity record PubChem Compound Summary: Promethazine.
    Compound identity and naming record. It supplies chemistry context, not independent numerical support for the model.
BoundariesWhat this page cannot answer and where to continue

What this page does not answer

  • It does not estimate impairment, intoxication, or fitness to drive.
  • It does not predict urine, blood, saliva, or hair test results.
  • It does not model repeated exposure, tolerance, withdrawal, or interactions.
  • It does not replace clinician, pharmacist, toxicologist, or emergency guidance.

Continue with context

Read the medical disclaimer, methodology, and research standards before using the model for comparison.