100 Migraine Drugs, A to Z: venlafaxine
Venlafaxine (Effexor) is the first drug in the serotonin-norepinephrine reuptake inhibitors (SNRI) class. It was approved by the FDA for the treatment of depression in 1993.
At low doses, venlafaxine works as a selective serotonin reuptake inhibitor (SSRI) such as fluoxetine (Prozac). SNRIs are considered to be effective for the treatment of pain and migraine headaches. SSRIs are not. A review of studies that involved a total of 418 patients showed that SNRIs are effective for the prevention of migraines. The class of SNRIs includes duloxetine (Cymbalta), desvenlafaxine (Pristiq), milnacipran (Savella), and levomilnacipran (Fetzima). Milnacipran is the only SNRI that is approved by the FDA for the treatment of fibromyalgia rather than depression.
In treating migraines, a 60-patient trial showed that the 150 mg dose is more effective than 75 mg.
Venlafaxine is started at 37.5 or 75 mg dose. After a week or two, the dose is increased to 150 mg. The maximum daily dose of venlafaxine is 450 mg.
Potential side effects include insomnia, drowsiness, fatigue, nausea, dizziness, suicidal thoughts in depressed children and young adults, and others.
Just like with other SNRIs, sudden discontinuation of venlafaxine can cause withdrawal symptoms. These may include one or more of the following: dizziness, headache, nausea, diarrhea, paresthesia (pins-and-needles), irritability, vomiting, insomnia, anxiety, sweating, and fatigue. SNRIs are stopped after a slow and gradual reduction of the dose.
It can take a week after the first treatment or up to a month or two. The first treatment can be only 20-30% effective but the next one could be 50-60% effective and so on.
Thanks Dr. Mauskop! And in your experience, how long does it take for Botox to have an effect? Knowing that every patient is different, of course. Thanks again for your help.
I agree with your family doctor. The risk of serotonin syndrome is very low, although it is not zero. Over the past 30 years, I’ve seen some patients who developed serotonin syndrome. Most had mild symptoms but a handful had a more severe and unpleasant experience. Botox, on the other hand, is safer than any drug taken by mouth or injection.
Hi Dr. Mauskop, I was recently prescribed venlafaxine to help treat anxiety with panic and chronic migraines, and I am concerned about taking it at the same time as eletriptan (which I take quite regularly), in terms of the risk of serotonin syndrome. My family doctor said that this risk is low, and that they will monitor me closely. Have any of your patients dealt with serotonin syndrome, and what was your recommendation if so? I’ve also been referred to a neurologist to talk to them about Botox, so I hope one or both treatments will help. Thanks for your time and consideration.