Enalapril Maleate and Doxorubicin Hydrochloride in Treating Women With Breast Cancer

This study is a drug interaction study designed to study the effects of enalapril on doxorubicin metabolism. Women with breast cancer for whom at least two cycles every 14 day doxorubicin is planned will be considered for enrollment. Study participation will be for 2 treatment cycles of doxorubicin or approximately 4 weeks. Patients will receive a 14 day course of daily enalapril in association with one cycle of doxorubicin and receive no study agent during the other cycle allowing patients to act as their own control. The sequence of enalapril dosing will be assigned by randomization at study enrollment. Blood samples for pharmacokinetics will be drawn before and at 7 time points after each of the two doses of doxorubicin. For each patient, serum doxorubicin and doxorubicinol concentrations both on and off of enalapril will be compared.

Inclusion criteria

• Tissue diagnosis of a breast carcinoma
• The oncologist must have prescribed doxorubicin as part of the planned chemotherapy regimen
• Have acceptable organ function within 14 days of enrollment defined as:

• liver function: total bilirubin, AST and ALT within normal institutional limits
• kidney function: estimated Creatinine Clearance > 60 ml/min calculated creatinine clearance (for females) - formula: (140 - age) x weight x .85 divided by (sCr x 72)
• At least 18 years old
• Patient must have given written informed consent indicating an understanding of the investigational nature of the study
• Agrees not to consume grapefruit juice while on the study

Exclusion criteria

• Known allergy to enalapril
• Taking any known P450 cytochrome inducers or inhibitors
• Taking any herbal supplements while on the study or the week prior to receiving doxorubicin
• Taking an ace-inhibitor or angiotensin receptor blocker
• Pregnant or lactating. Enalapril is Pregnancy Categories C (first trimester) and D (second and third trimesters)