Related Experiment Video
Updated: Jun 16, 2026

Pretargeted Radioimmunotherapy Based on the Inverse Electron Demand Diels-Alder Reaction
Published on: January 29, 2019
Coping with changes in the Defined Daily Dose in a longitudinal drug consumption database
Vera Vlahović-Palcevski1, Monja Gantumur, Nives Radosević
1Department of Clinical Pharmacology, University Hospital Rijeka, Kresimirova 42, Rijeka, 51000, Croatia. vvlahovic@inet.hr
Objective:
To illustrate the best approach to accurate representation of temporal evolution of drug consumption, when confronted with changes over time in the Defined Daily Dose (DDD) measurement unit.
Method:
As an example, drug consumption (2001-2005) at the University Hospital Rijeka was expressed with the corresponding DDD in each year; and with the DDD value of the last year of the observation time window. By visual appraisal, results with both methods were compared with the graph of drug consumption trends expressed in physical units (mg, IU, etc.).
Results:
Of 20 drugs for which the DDD value has changed in the 5 year period, 5 were used in Rijeka hospital: erythropoietin parenteral, budesonide nasal spray, repaglinide oral, amoxicillin with clavulanic acid parenteral, and fentanyl transdermal. Graphs for individual drugs with the year by year method showed artificial jerks in the years proceeding the year of DDD change. Representation of total hospital consumption did not differ notably with the two methods.
Conclusion:
Drug consumption data should be calculated with the latest DDD value in the time window. The policy of the World Health Organisation to keep changes to the system of DDD to a minimum should be continued.
Related Concept Videos
Dosage Regimen: Fixed Dose
Fixed-dose regimens can be used for various routes of administration, including intravenous (IV) injections and oral medications. For IV administration, a predetermined amount of the drug is...
Dosage Regimens: Designs and Approaches
Drug Accumulation During Multiple Dosing: Repetitive IV Injections
Dosage Regimen: Multiple Oral Dosage
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,...
Drug Dosage Regimen: Overview
Typically, the starting dose and dosing interval are guided by the manufacturer's recommendations based on clinical trials conducted during and after drug...

