Posted by SLS on December 29, 2012, at 7:44:17
In reply to question for SLS » SLS, posted by g_g_g_unit on December 29, 2012, at 1:41:32
I spent about an hour researching 5-HT3 receptors and am now more confused now than before I started. I had begun to write a long-winded explanation, but quickly found that the subject would require more study to offer any meaningful understanding at this time. 5-HT3 receptor function and dynamics are complex and variable, and depends upon the neuroal circuits they appear in and the species being studied.
As far as I can see, memantine acts as an antagonist of serotonin 5-HT3 receptors at concentrations comparable to those producing NMDA antagonism. However, any small difference in the numbers observed in the lab might translate to a significant difference in therapeutic dosage. Phiddipus might be right. I can't be sure. However, because memantine can help with OCD, I think this might be reason enough for you to try it again. I don't think you can evaluate memantine until you can establish a dosage of 20 mg/day. If anxiety prevents you from doing this, I would discontinue it. From what I gather, antagonism of 5-HT3 receptors in the amygdala can lead to a reduction in the activity of GABA neurons there. This might account for the anxiety you experience. It might dissipate with continued treatment, though, as I believe the presynaptic membrane becomes desensitized quickly. If it doesn't dissipate, this may be a clue into what is going on with you - amygdala hyperactivity. How do you react to Neurontin (gabapentin)? Perhaps prazosin would help.
What if you were to attack the ADD, anxiety, and OCD first? Do you think the depression would resolve?
As always, it would be nice to have your doctor support you during a treatment experiment. However, if it were me, I would probably try the memantine again and push the dosage to 20 mg/day or higher. Take things one step at a time, though. See if the startup anxiety is tolerable using the recommended titration schedule. If the inceased anxiety persists for two weeks or is otherwise intolerable, I would stop taking it. Your amygdala might be hyperactive. If you do manage to establish a dosage of 20 mg/day without adverse effects, you might as well leave it on board as you try adding Nardil, Viibryd, or clomipramine.
Nardil + Focalin + memantine might be interesting.
Recommended NAMENDA dosing schedule:Week 1: Starting on Day 1. Take one 5 mg tablet in the morning, each day.
Week 2: Starting on Day 8. Take one 5 mg tablet in the morning and one 5 mg tablet at night, each day.
Week 3: Starting on Day 15. Take one 10 mg tablet in the morning and one 5 mg tablet at night, each day.
Week 4: Starting on Day 22. Take one 10 mg tablet in the morning and one 10 mg tablet at night, each day.
- Scott
this signature | Show by default | Change to hide (next time)Some see things as they are and ask why.
I dream of things that never were and ask why not.- George Bernard Shaw
poster:SLS
thread:1033817
URL: http://www.dr-bob.org/babble/20121217/msgs/1034119.html