Use of drugs that act on the cytochrome P450 system in the elderly.

Objectives: The objective of this study was to analyze medications that act on the cytochrome P450 (CYP450) enzymatic system and are used daily by non-institutionalized elderly individuals.

Methods: A cross-sectional population-based study of elderly individuals (> or = 60 years old) was conducted. All continuously used medications with hepatic metabolism via CYP450 that are classified as substrates, inducers or inhibitors were considered.