Memantine
Memantine, brand name Namenda, was initially approved to help slow the progress of dementia. Over time it became obvious that it helped other conditions including OCD, ADHD, and depression.
What is the mechanism of action of Memantine?
It works as a NMDA receptor antagonist. NMDA receptors play a pivotal role in many brain functions including how easily “activated” various cells are. Memantine also has activity as a serotonin antagonist (at 5-HT3) and can have downstream effects activating dopamine.
How effective is Memantine for OCD?
Studies are emerging but results are promising:
-As many as 80% of patients respond in some clinical studies.
-In this study, there was an average of 27% decrease in OCD symptoms.
What is the usual dose of memantine for OCD?
If insurance will cover it, we would start with the extended release version at 7mg/day and increase by 7mg every week. The goal dose is 21 to 28mg/day.
If the immediate release is used, we start at 5mg/day for 7 days then increase by 5mg every week, but at 2x per day. The goal dose is 10mg 2x per day.
How long should patients take memantine before giving up on it?
Studies show that benefits continue to accrue up to 12 weeks out from the last increase in dose.
Are there other benefits that might occur with memantine?
Yes, patients' depression scores also improved.
In this study it was shown to help in the treatment of adult ADHD.
Is memantine safe in bipolar disorder?
It has not been thoroughly studied but there is some evidence it is safe and that it can even help in the treatment of manic episodes.
What are the side effects of memantine?
For most, the “side effects are mild” and many studies had no participants withdraw because of side effects. In this study there was no difference in side effects between memantine and a sugar pill.
But side effects still can occur. Please visit this site for a comprehensive list.
Does this mean memantine is a first-line treatment for OCD?
No, it is not FDA approved for OCD and it is reserved for patients who have not responded well to a combination of EXRP therapy and SSRI antidepressants, which are considered the 1st-line treatment for OCD. There are many other classes of medications which may help OCD including SNRIs, TCA antidepressants, and atypical antipsychotics. There are also some supplements that may be helpful-- if interested, please click here to learn more about a supplement called NAC that can help treat OCD.
