Tamoxifen Pharmacovigilance: Implications for Safe Use in the Future.

OBJECTIVE

To survey the status of current tamoxifen pharmacovigilance documentation reflecting tamoxifen use in an academic outpatient multispecialty practice in older adults. This data will help provide information to develop improved pharmacovigilance for a growing cohort of older adult users. The data will be utilized by an interdisciplinary team developing new methods of identifying factors for individualized pharmacovigilance in older adults.

DESIGN

Retrospective chart review to gather descriptive and quantitative data on tamoxifen pharmacovigilance.

SETTING

Multi-specialty clinic.

PATIENTS

Ninety-three patients 60 years of age and older.

MAIN OUTCOME MEASURES

Quantitative report of tamoxifen monitoring as well as descriptive analysis of individual cases.

RESULTS

We found 19 cases of serious adverse events possibly related to tamoxifen (thrombi, uterine malignancies). There were 15 cases with no documentation of pharmacovigilance. All cases had incomplete pharmacovigilance documented. There were two cases of hypercalcemia. There was one case of tamoxifen discontinuation resulting from muscle pain and with chronic muscle pain complaints while receiving tamoxifen. We observed a correlation in older age or high comorbidity burden patients and adverse events patients.

CONCLUSION

Some studies direct the important pharmacovigilance toward prevention of thrombi, uterine malignancies, and hypercalcemia; however, it is not easy to identify recommendations for frequency or focus of monitoring to prevent adverse events for individual older adults based on existing recommendations. The data collected and presented in this study serve to heighten awareness of tamoxifen pharmacovigilance and as a starting point for the application of machine learning techniques and modeling to identify high-risk patients and individualized pharmacovigilance recommendations.