Sleep-Related Headache Following Metformin Use: Hypnic or Toxic?

Headache is among the most frequently encountered symptoms in clinical practice. Occipital neuralgia is characterized by sudden, sharp, electric shock-like pains in the distribution area of the occipital nerve. In this report, we present a 54-year-old female patient who developed occipital neuralgia-like symptoms shortly after the initiation of metformin treatment for type 2 diabetes mellitus. The symptoms resolved following the discontinuation of the drug. This case is discussed in light of the literature to highlight a potentially rare headache pattern triggered by metformin. This case describes an unusual form of headache possibly associated with metformin therapy. It underscores the importance of considering uncommon side effects of commonly prescribed medications, such as metformin in differential diagnoses.