Dysosmia and drug tolerance with use of venlafaxine

A 57-year-old woman presented with a 1-year history of major depressive disorder. She was started on venlafaxine XR 75 mg orally daily and a few days later developed severe dysosmia to foods she used to enjoy. She never had previous problems with smell or taste. At her 1-month follow-up, her depressive symptoms had improved, but she reported persistent dysosmia and was found to have associated weight loss due to decreased oral intake. She was advised to switch medications, but due to financial constraints she continued taking the same dose. At follow-up 48 days later, she reported complete resolution of her dysosmia and was eating normally again, but she had persistence of some depressive symptoms so her dose was gradually increased to venlafaxine XR 225 mg orally daily until her depressive symptoms and postmenopausal hot flashes were well controlled. There were no changes with continued use over the following 8 years.