When starting on pain medication, you may feel more tired than before, but this eases over time once you settle on the proper dose of pain medication. On the other hand, the patient has often experienced sleeplessness due to pain, which has resulted in sleep deprivation. With the help of good pain medication, the patient is finally able to rest. At the end of life, fatigue also intensifies due to the progression of the illness, in which case feeling more tired may not have to do with pain medication.
Why do pain medications make you feel tired?
Many pain medications work by affecting the pain control mechanisms of the central nervous system, and the effects on the central nervous system at least partly explain why you’re feeling tired.
Updated 12.3.2026