Related Experiment Video
Updated: Aug 7, 2026
10:17
High-throughput and Comprehensive Drug Surveillance Using Multisegment Injection-Capillary Electrophoresis-Mass Spectrometry
Published on: April 23, 2019
Correlation of saliva codeine concentrations with plasma concentrations after oral codeine administration
C L O'Neal1, D J Crouch, D E Rollins
1Center for Human Toxicology, University of Utah, Department of Pharmacology and Toxicology, Salt Lake City 84112, USA.
Journal of Analytical Toxicology
|October 12, 1999
Summary
Saliva codeine concentrations can estimate plasma levels after oral contamination clears. A consistent saliva/plasma ratio was observed, but caution is advised due to variability.
Area of Science:
- Pharmacokinetics
- Analytical Chemistry
- Clinical Pharmacology
Background:
- Saliva is a non-invasive matrix for drug monitoring.
- Predicting plasma drug concentrations from saliva requires understanding their relationship.
Purpose of the Study:
- To investigate the relationship between saliva and plasma codeine concentrations.
- To determine if saliva can be used to estimate plasma codeine levels.
Main Methods:
- 17 drug-free volunteers received 30 mg liquid codeine phosphate.
- Plasma and saliva samples were collected over 24 hours.
- Codeine and morphine analyzed using gas chromatography-mass spectrometry.
Main Results:
- Early saliva samples showed high codeine due to oral contamination.
- After 2 hours, saliva codeine concentrations declined similarly to plasma but remained higher.
- A significant correlation (r=0.809) between saliva and plasma codeine was found post-absorption, with a stable saliva/plasma ratio (mean=3.7).
Conclusions:
- Saliva codeine concentrations can estimate plasma levels after oral contamination is resolved.
- The saliva/plasma ratio is a potential tool for estimating codeine plasma concentrations.
- Caution is necessary due to intersubject variability and the need to exclude oral contamination.
More Related Videos
Related Concept Videos
01:14Time Course of Drug Effect
The progression of a drug's impact can be analyzed by examining both the concentration-time course and the effect-time course. The concentration-time course is determined by the drug's half-life and is influenced by factors such as its pharmacokinetics, including absorption, distribution, metabolism, and elimination. The effect of the drug is often related to its concentration in the plasma and is calculated using the maximum drug effect and the plasma concentration that generates 50 percent of...
01:15Drug Concentration Versus Time Correlation
The plasma drug concentration-time curve is a crucial tool in pharmacokinetics, representing the drug's concentration in plasma at different time intervals post-administration. This curve illustrates the drug's journey from absorption into the systemic circulation, distribution to body tissues, and eventual elimination through excretion or biotransformation.
Two pivotal parameters are the minimum effective concentration (MEC) and the minimum toxic concentration (MTC). The MEC is the lowest drug...
Two pivotal parameters are the minimum effective concentration (MEC) and the minimum toxic concentration (MTC). The MEC is the lowest drug...
01:23Drug Concentrations: Measurements
Drug concentration is the quantity of a drug present in a biological sample. Measuring drug amounts in biological samples allows the clinician to understand how a drug is absorbed, distributed, metabolized, and excreted. Samples can be obtained through invasive or non-invasive methods. Invasive techniques involve surgical or parenteral interventions to gather blood, cerebrospinal fluid, or tissue biopsy. Conversely, non-invasive approaches provide samples like urine, feces, and saliva.
Plasma —...
Plasma —...
01:20Drug Product Performance: In Vitro–In Vivo Correlation
In pharmaceutical development, it's crucial to establish a predictive in vitro–in vivo correlation (IVIVC) for two or more formulations to gain a comprehensive understanding of release properties. IVIVC reduces the need for costly in vivo studies and facilitates the establishment of meaningful dissolution specifications with significant cost savings and decreased regulatory burden. Furthermore, a meaningful IVIVC should predict Cmax and AUC within 20%, aligning with FDA guidance while adhering...
01:25Dosage Regimen: Multiple Oral Dosage
Understanding how a drug's concentration fluctuates within the body over time is crucial in pharmacokinetics, particularly with multiple oral doses. A graphical representation of multiple oral dosages provides insight into these dynamics. Typical accumulation curves of a drug's concentration in the body reveal a sawtooth pattern, indicating periodic peaks and troughs correlating with each dose administration and the drug's subsequent elimination.The plasma concentration at any time during an...
01:28Pharmacokinetic–Pharmacodynamic Relationship: Dose to Pharmacological Effect
A drug’s dosage and pharmacokinetic properties determine how quickly it acts, how intense its effects are, and how long it lasts. Higher doses increase drug concentration at receptor sites, producing a hyperbolic curve when pharmacologic response is plotted against drug dose. Converting this scale to a log-linear format results in a sigmoidal curve, better representing dose–response relationships.For drugs following a one-compartment model, the pharmacologic response is directly proportional to...