Cymbalta is used to treat major depressive disorder and general anxiety disorder. It is also used to treat a chronic pain disorder called fibromyalgia, and to treat pain caused by nerve damage in people with diabetes (diabetic neuropathy).
Caffeine-withdrawal headaches can last up to 48 hours and can be as intense as a migraine headache. Withdrawal symptoms can begin 12 to 24 hours after the last cup of coffee and can last up to 1 week. These symptoms can include lethargy, extreme nervousness, irritability, sweating, headaches and shakiness.
Kuhar explained that caffeine blocks receptors in the brain that can dilate blood vessels causing headaches. Withdrawal symptoms can start from 12 to 20 hours after your last cup of coffee and peak about two days later and can last about as long as a week, Kuhar added.