Related Experiment Video
Updated: Aug 12, 2026

The Goeckerman Regimen for the Treatment of Moderate to Severe Psoriasis
Published on: July 11, 2013
Is there an optimal time to administer methotrexate in the treatment of rheumatoid arthritis?
N Carpentier1, P Bertin, P Marquet
1Department of Rheumatology, Dupuytren University Hospital, Limoges, France.
Objective:
To determine the optimal time to administer methotrexate (MTX) in rheumatoid arthritis (RA).
Methods:
In a crossover study 23 patients were administered MTX intramuscularly at either 10 AM or 6 PM. A 2 week interval separated the 2 injections. MTX concentrations were measured using a fluorescence polarization immunoassay. Pharmacokinetic variables were estimated using a Bayesian approach. The morning and evening schedules were compared using analysis of variance to determine the optimal time of injection.
Results:
No statistical difference was found in the pharmacokinetics of MTX according to hour of injection. A difference in the creatinine clearance, however, was observed in the samples obtained at noon and 8 PM, but clearance of MTX was unchanged.
Conclusion:
Pharmacokinetic variables suggest that MTX can be administered either in the morning (10 AM) or evening (6 PM) in the treatment of RA.
Related Concept Videos
Rational Dosage Regimen: Maintenance Dose and Loading Dose
In most cases, drugs are administered repetitively or infused continuously to maintain a steady-state concentration in the body. At a steady state,...
Drugs for Treatment of Crohn's Disease in IBD Using Immunomodulatory Agents
Drugs for Treatment of Crohn's Disease in IBD Using Biologic Agents: Anti-TNF
Drugs for Treatment of Crohn's Disease in IBD Using Glucocorticoids
Chronopharmacokinetics: Circadian Rhythms and Influence on Drug Response
The time of drug administration is an important factor to consider, as it can influence the toxic dose of a drug. For example, a study conducted by Prins et al. in 1997 examined the effects of the timing of...
Therapeutic Drug Monitoring: Affecting Factors

