Hydroxyzine (Vistaril) is an underutilized old anti-histamine drug with some unique properties. Just like diphenhydramine (Benadryl) and other older anti-histamine drugs, hydroxyzine causes some sedation. However, it is the only anti-histamine that is officially approved for “anxiety and tension”. It is also approved for itching due to allergic conditions. Off-label (i.e. without FDA-approval) it is used to treat motion sickness, nausea, vomiting, and dizziness.
Hydroxyzine is often used as and adjuvant analgesic, that is as an add-on drug that makes pain medications work better.
A study comparing an injection of hydroxyzine 50 mg plus meperidine (Demerol, a narcotic pain killer), 100 mg was similar to an injection of ketorolac (Toradol) 60 mg in its relief of an acute migraine. Nausea and drowsiness were similar in two groups.
There have been no studies examining the efficacy of hydroxyzine alone, whether as an intravenous or intramuscular injection or as a tablet. It is likely that it will remain an adjuvant or add-on medication for the treatment of migraine headaches.
I sometimes prescribe it to be taken daily to patients whose allergies worsen their migraine headaches or even when there is only a suspicion of an allergic component. It is also useful when anxiety is a contributing factor, which is not unusual since those suffering from migraines are 2-3 times more likely to also have anxiety. For many patients it is too sedating to be taken during the day, unless they are treating an acute attack. Most people take 25 or 50 mg nightly, although some tolerate and benefit from 25 mg taken three times a day.
