Desvenlafaxine (Pristiq) is an antidepressant in the family of serotonin and norepinephrine reuptake inhibitors (SNRIs). Selective serotonin reuptake inhibitors (SSRIs) such as fluoxetine (Prozac) and escitalopram (Lexapro) are more popular for the treatment of depression and anxiety, but they are less effective than SNRIs for the prevention of migraines and the treatment of pain. Venlafaxine (Effexor) was the first drug in the class of SNRIs, but at the doses below 150 mg works as an SSRI, inhibiting only the reuptake of serotonin. At 150 mg it begins to inhibit the reuptake of norepinephrine, which is responsible for pain relief.
Venlafaxine is broken down in the body into an active metabolite, desvenlafaxine. So desvenlafaxine can be considered a purified form of venlafaxine. The FDA approved recommended starting and maintenance dose for desvenlafaxine is 50 mg daily and this dose produces the dual effect, while venlafaxine requires titration from 37.5 mg daily to the maintenance dose of 150 – 300 mg daily. Potential side effects of desvenlafaxine include increased or excessive sweating, dizziness, drowsiness, dry mouth, constipation, insomnia, and loss of appetite.
While venlafaxine has been shown to prevent migraine headaches, such research is lacking for desvenlafaxine. However, considering that two other SNRI drugs, duloxetine (Cymbalta) and milnacipran (Savella) are FDA-approved for pain, it is very likely that desvenlafaxine can also help prevent migraines and relieve other types of pain.
