Topiramate is generally safe for long-term migraine prevention if well-tolerated. However, because your wife has been taking it since 2002, a routine consultation with her doctor is highly recommended. Prolonged use can sometimes increase risks like kidney stones or gradual bone density loss. Additionally, migraine patterns change over time, and several highly effective, newer preventive treatments with fewer side effects have become available since she started. She should not stop the medication abruptly, as this can cause migraines to return worse than before. Instead, she should visit her doctor to check her kidney function and discuss whether continuing this medication or transitioning to a modern alternative is best.