insomnia
"My doctor prescribed Doxepin 45 mg  "at bedtime" to help me move my sleep cycle back to  a normal time - it had gradually slipped later and later until I wasn't getting sleepy until 4-6 am. My experience is that Doxepin is useless for this purpose (confirmed by my pharmacist) - it does not help me fall asleep at all, but it will keep me asleep for much longer which unfortunately is just reinforcing my shifted sleep cycle.  In addition I've had lots of side-effects, ranging from a mild headache to migraine halos, irritability, anxiety, and worst of all, a 20 point rise in the first blood glucose reading after waking.  If your problem is staying asleep this will probably help, but if your problem is falling asleep it's pretty useless,"