Effexor (Venlafaxine hydrochloride) is a serotonin and norepinephrine reuptake inhibitor (SNRI) approved to treat depression. Effexor XR, the extended-release version, is approved to treat depression, generalized anxiety disorder and social anxiety disorder. Additionally, Effexor and Effexor XR are used off label for treatment of ADD.
Attention Deficit Disorder is not an objectively quantifiable illness, rather its diagnosis is based on what a majority people subjectively deem to be normal behaviour. As such, there are both pro and con views about medicating ADD. Leaving such questions aside, lets look at a few of the facts about ADD and Effexor.
Medications for ADD and other mental disorders work by affecting your brains neurotransmitters, which are naturally occurring chemicals which relay and modulate signals between the brains neurons. Neurotransmitter science is a complex subject, and to make things more interesting, different drugs interact with them in different ways, and each individual brain also reacts differently.
The primary neurotransmitters believed to involved in ADD are norepinephrine and dopamine, and to a lesser extent, serotonin. Medications can be reuptake inhibitors – these make more of the neurotransmitter available by preventing its reabsorption into the emiiting neurons- they can be agonists (the opposite of an “antagonist”) a drug that stimulates activity at cell receptors- and some drugs do both at the same time.
Neurotransmitters also interact with one another, so changes in the level of one will cause changes to another. Finally, the way a medication reacts in your brain also depends on the dosage; the same drug higher doses may work via a substantially different mechanism than it does at low doses.
Effexor is a reuptake inhibitor of both serotonin and norepinephrine, and is classified as an SNRI (serotonin-norepinephrine reuptake inhibitor). Some doctors are beginning to prescribe Effexor off label for treatment of diabetic neuropathy and migraine prevention. Studies have suggested it has some effectiveness. Investigations have also been shown Effexor to reduce severity of hot-flashes in menopausal women.
Adverse Effexor Effects
Nineteen percent of venlafaxine (Effexor) treated patients in Phase II and III depression trials discontinued the treatment because of an adverse reaction. Read that again before you go further. The lack of sexual desire, just as with most antidepressants, is a common complaint. The most common side effects, according to the manufacturer, Wyeth, are:
- Nausea (21-35% of people that experienced the side effect in clinical trials)
- Headache (34%)
- Ongoing Irritable Bowel Syndrome
- Dizziness (11-20%)
- Insomnia (15-23%)
- Dry mouth (12-16%)
- Sexual dysfunction (14-34%)
- Sweating (10-14%)
- Vivid dreams (3-7%)
- Impulsive Actions
- Increased blood pressure
- Decreased Appetite (8-20%)
- Electric shock-like sensations also called “Brain zaps”
The other thing to be aware of is that Effexor is said to be very hard to get off of. The so called “discontinuation syndrome” can be quite protracted.
Use in ADD
Drugs that were developed as antidepressant treatments are used less often for ADD than stimulant medications, but some doctors feel them to be effective with use in some children. Antidepressants that actively effect the neurotransmitter norepinephrine, such as Effexor, can have an effect on ADD, and are used where contraindications to stimulant medications (Ritalin, Adderall etc) exist, or when the stimulant medications have not been effective, or when severe side effects have resulted from them.
Antidepressants that affect serotonin- SSRIs like Prozac, Zoloft or Paxil- have no effect on ADD symptoms, but can some doctors believe they can be effectual where there is co-existing depression conditions.
Is there any dependable scientific evidence that Effexor for ADD is effective? At the time of this writing, (Fall 2007) no.
There are several short-term, uncontrolled trials in the literature which give some clues, however. One 2002 study (Prog Neuropsychopharmacol Biol Psychiatry. 2002 Apr;26(3):585-9.) concluded that treatment with Effexor by itself may have similar efficacy to treatment with a combination of stimulant and antidepressant therapy. It may also be better than stimulant therapy alone, in patients with both depression and ADD. But they added that more controlled, prospective trials with larger patient samples are needed to confirm their observations.