Abdominal problems. Certain pain relievers called nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Advil, Motrin IB, others), may cause abdominal pain, bleeding, ulcers and other complications, especially if taken in large doses or for a long period of time.
Medication-overuse headaches. If you take over-the-counter or prescription headache medications more than 10 days a month for three months, or in high doses, you may be setting yourself up for a serious complication known as medication-overuse headaches.
Medication-overuse headaches occur when medications not only stop relieving pain but also cause headaches. You then use more pain medication, which continues the cycle.
Serotonin syndrome. Serotonin syndrome is a rare, potentially life-threatening condition that occurs when your body has too much serotonin, which is a chemical found in your nervous system. It may occur if you take migraine medications called triptans and antidepressants known as selective serotonin reuptake inhibitors (SSRIs) or serotonin and norepinephrine reuptake inhibitors (SNRIs).
These medications naturally raise serotonin levels. When combined, they cause increased serotonin levels in your system, more than if you were taking one of these medications.