Codeine half-life
Codeine’s roughly three-hour parent half-life is only part of the story because CYP2D6-dependent conversion to morphine varies between people.
Every curve begins at 100%. No dose or measured body concentration is assumed.
X-axis: elapsed time. Y-axis: modeled percentage of the relative starting point remaining. This is a mathematical visualization, not a personal concentration estimate.
Codeine: evidence and interpretation notes
Parent drug, metabolites, and formulation
Codeine’s roughly three-hour parent half-life is only part of the story because CYP2D6-dependent conversion to morphine varies between people. The profile keeps pharmacogenetic context beside the parent-drug line.
For the interactive chart, HalfLifeDB starts with 3 hours as the representative value for Codeine. Route, formulation, sampling, and metabolites remain attached to that label instead of being hidden inside the arithmetic.
Codeine is pharmacokinetically important because CYP2D6 metabolism can change how much morphine is formed from the parent drug. That makes a simple parent-compound curve incomplete by design.
The 3 hour value is used for the educational curve, but clinical response and risk can depend on metabolism, formulation, and combination products.
The citations include a direct codeine-containing DailyMed label, a compound record, and a pharmacogenetics guideline that explains why metabolism matters.
Do not use this page to guide analgesic use, dosing, or safety decisions.
For Codeine, parent-drug decline should be read separately from analgesia, respiratory risk, metabolites, and formulation. Opioid risk is not proportional to the percentage remaining in this simplified chart.
What each source contributes
- DailyMed: Acetaminophen and codeine phosphate tablet. 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.
- Crews KR et al. Clinical Pharmacogenetics Implementation Consortium guideline for CYP2D6 and codeine therapy (2014 update). This supporting literature record adds compound-specific background and is used only within the limits of its design.
For Codeine, the numerical model is tied most closely to DailyMed: Acetaminophen and codeine phosphate tablet. As a product label, it adds formulation-specific pharmacokinetic context; it does not represent every route or product.
Why there is no range on the chart
This profile plots 3 hours for Codeine without adding an unsourced high-low band. A single supported center is more honest than manufacturing a range from unrelated routes, populations, or formulations.
InterpretationReading the curve and its category context
Reading this curve
HalfLifeDB uses 3 h as a representative input for Codeine. In the simplified model, about 0.4% remains after 24 hours and about 3% remains after five half-lives, or roughly 15 h.
This is a short curve. The modeled amount changes noticeably over the same day, while effects, metabolites, and safety questions can still follow a different timeline. The curve is relative: it does not estimate a person's measured concentration, effects, impairment, or time to clearance.
opioid context
Opioid pharmacokinetics can differ between parent compounds and metabolites, and timing can vary by route, formulation, and individual clearance.
- Half-life is not a measure of respiratory risk or functional impairment.
- Active metabolites can matter even when the parent compound declines.
- Extended-release products require separate source context.
ComparisonTimeline checkpoints and nearby profiles
Codeine timeline checkpoints
| Elapsed time | Modeled remaining | Reading note |
|---|---|---|
| 6 h | 25.0% | Long-tail portion of the model |
| 12 h | 6.25% | Low modeled remainder, not a clearance guarantee |
| 24 h | 0.39% | Low modeled remainder, not a clearance guarantee |
| 2.0 days | 0.00% | Low modeled remainder, not a clearance guarantee |
| 3.0 days | 0.00% | Low modeled remainder, not a clearance guarantee |
Nearby profiles by half-life
These entries sit near Codeine within the opioid group when sorted by representative half-life. That makes them curve comparisons, not statements about equal potency, effects, or risk.
- Hydromorphone (2.3 h)
- Meperidine (3 h)
- Morphine (2 h)
- Oxycodone (3.5 h)
EvidencePharmacokinetic inputs and source trail
Pharmacokinetics at a glance
| Representative half-life | 3 h |
|---|---|
| Curve type | Normalized, first-order decline |
Selection note: Codeine’s roughly three-hour parent half-life is only part of the story because CYP2D6-dependent conversion to morphine varies between people. The profile keeps pharmacogenetic context beside the parent-drug line.
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.
- Official labeling DailyMed label: Acetaminophen and codeine phosphate tablet.Official U.S. product labeling used for formulation and labeled pharmacokinetic context; its statements apply to the described product.
- Identity record PubChem Compound Summary: Codeine.Compound identity and naming record. It supplies chemistry context, not independent numerical support for the model.
- Research abstract Crews KR et al. Clinical Pharmacogenetics Implementation Consortium guideline for CYP2D6 and codeine therapy (2014 update).Supporting literature record. Its role and study design should be read from the linked source before applying any numerical finding.
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
- All substance profiles
- Browse the opioid group
- Compare this curve
- Clearance and volume of distribution
- Bioavailability, route, and formulation
- Active metabolites and parent compounds
- First-order vs nonlinear kinetics
- Detection windows vs half-life
- Reading labels and source quality
Read the medical disclaimer, methodology, and research standards before using the model for comparison.