Posted by g_g_g_unit on December 29, 2012, at 21:46:10
In reply to Re: question for SLS » g_g_g_unit, posted by SLS on December 29, 2012, at 7:44:17
Thanks so much for your reply Scott.
For the record, I *did* recently try Memantine in a dose range from 2.5mg-15mg and only experienced an increase in anxiety and agitation. At 10mg, and again 15mg, I gave each dose two weeks to adjust, but the increased anxiety never dissipated, which is what forced me to discontinue.
I thought perhaps that 20mg might yield some alternate effects, so was considering just starting directly at 20mg without titrating, though if I reacted badly to lower doses, perhaps it isn't worth my time?
> 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
poster:g_g_g_unit
thread:1033817
URL: http://www.dr-bob.org/babble/20121217/msgs/1034181.html