Potential drug interactions with the percent carbohydrate-deficient transferrin (%CDT) test, a new alcohol biomarker.

STUDY

OBJECTIVE

To determine the effects of drugs on levels of carbohydrate-deficient transferrin (CDT), using the %CDT test, a new alcohol biomarker, in patients receiving drug therapy for chronic medical conditions such as diabetes mellitus, hypertension, and lipid disorders.

DESIGN

Regression analysis of transformed data.

SETTING

Eight primary care clinics in central Wisconsin.

PATIENTS: Seven hundred ninety-nine primary care patients who were prescribed drug therapy for a variety of chronic illnesses such as diabetes, hypertension, and lipid disorders.

MEASUREMENTS AND MAIN

RESULTS

The %CDT level, 30-day history of alcohol consumption, symptoms of alcohol abuse or dependence, health status, and prescribed drugs were determined for each patient. All prescribed drugs that were taken by the patients in the last month were determined by self-report, medical records, or pharmacy records. Of the 799 patients, 89 were receiving drug therapy for diabetes, 299 for hypertension, 209 for both diabetes and hypertension, and 202 for medical conditions other than diabetes or hypertension. A regression analysis was performed after the data were transformed. Alcohol consumption, sex, age, tobacco use, and 20 drug classes were entered into the model. Factors associated with increased %CDT levels were alcohol consumption, female sex, and bupropion use. Two additional drug classes, the angiotensin II receptor blockers and the tricyclic antidepressants, were associated with lower %CDT levels. The effects of bupropion and tricyclic antidepressants on %CDT levels, however, appear to be confounded by alcohol intake.

CONCLUSION

This study suggests that only one of 20 drug classes-the angiotensin II receptor blockers-affected %CDT levels in our primary care sample. Additional research with larger samples is needed to focus on the effects of individual drugs used in general clinical settings on %CDT levels.