The typical first line treatments for hypnic headache are caffeine before bed (if tolerated), or upon waking with hypnic headache. Indomethacin before bed also shows benefit for some patients. However, if it is frequent enough, a daily preventive is often used. Lithium has been shown to be helpful in hypnic headache, although there is some evidence for a variety of other preventives as well (typically medications often used for migraine prevention). What successful treatments have you used?