86 Eur. J. Drug Metab. Pharmacokinet., 1997, No.1

Response to letter from Dr Schein:

We thank Dr Schein for his comments about our article and the effect of cruciferous vegetables and smoking on drugsmetabolized by CYPIA". We are also aware of an interesting report (1) that broccoli, smoking and exercise all increasethe metabolism of caffeine by CYPIA2. Research continues to unravel the complex effects of such factors on drugmetabolism, and it is a challenge to all health care providers to keep informed and incorporate this information into theirpractices. Accurately predicting, a priori, the cumulative effects of these factors on a patient's response to a particulardrug is still not possible; however, awareness of these factors and therapeutic drug monitoring can improve patient care.

Leonard Williams MDMedical Director

Geriatric, Evaluation and Managementand Subacute Units

Department of Yeterans AffairsMedical Center, Bay Pines FL 33504

REFERENCE

1 Vistisen K., Poulsen H.E.• Loft S. (1m): Foreign compound metabolism capacity in man measured from metabolism of dietary caffeine.Carcinogenesis, 13(9}. 1561-1568.