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Suggest Dosage For Namenda XR
Question: How long does it take for namenda xr to start working? I was started on the 28mg dose. Being used off-label for worstening "complex regional pain syndrome" secondary to multiple head & neck injuries (including branches of both trigeminal nerves" x 6 yrs.
Is namenda xr as effective as daily IV ketamine infusions x 5 days in binding to the "nmba receptors"
Thank you. XXXXXXX
(also on "LDN" now: low dose naltrexone 4mg q day); was also tried on tegretol, IV valproate acid, oral & nasal spray ketamine (didn't help the extremity pain at all) & other meds (listed).
Is namenda xr as effective as daily IV ketamine infusions x 5 days in binding to the "nmba receptors"
Thank you. XXXXXXX
(also on "LDN" now: low dose naltrexone 4mg q day); was also tried on tegretol, IV valproate acid, oral & nasal spray ketamine (didn't help the extremity pain at all) & other meds (listed).
Brief Answer:
About 2 weeks
Detailed Answer:
I read your question carefully and I understand your concern.
As you seem to be aware memantine (Namenda) is considered an off label treatment for CRPS. That is because there are very few studies involving only small numbers of patients. So the answer to your question is not that clear cut. However its effect should be felt in the first 2-4 weeks in most patients, if no efficacy is seen in two months at most then it would be considered ineffective.
As for direct comparisons to ketamine generally ketamine is considered more powerful (but higher potential of side effects). However these comparisons are not advisable. That is because there are different dosages and manners of administration. In addition regimens for CRPS are not well established, it is a condition which mechanisms are still not completely elucidated. There are not many studies neither with memantine nor with ketamine and dosages and duration varies among different studies, there is not one established dose and duration of therapy, may vary from one center to the other. Also when comparing ketamine and memantine they act on other different pathways as well which might play a role in efficacy.
From the long list of medications it is obvious that yours is a very difficult case. It seems that you have exhausted most options. Memantine seems to be worth trying at this point. Among other medications which you do not seem to mention are also the bisphosphonates, perhaps they may be considered in the future if memantine doesn't work.
I remain at your disposal for other questions.
About 2 weeks
Detailed Answer:
I read your question carefully and I understand your concern.
As you seem to be aware memantine (Namenda) is considered an off label treatment for CRPS. That is because there are very few studies involving only small numbers of patients. So the answer to your question is not that clear cut. However its effect should be felt in the first 2-4 weeks in most patients, if no efficacy is seen in two months at most then it would be considered ineffective.
As for direct comparisons to ketamine generally ketamine is considered more powerful (but higher potential of side effects). However these comparisons are not advisable. That is because there are different dosages and manners of administration. In addition regimens for CRPS are not well established, it is a condition which mechanisms are still not completely elucidated. There are not many studies neither with memantine nor with ketamine and dosages and duration varies among different studies, there is not one established dose and duration of therapy, may vary from one center to the other. Also when comparing ketamine and memantine they act on other different pathways as well which might play a role in efficacy.
From the long list of medications it is obvious that yours is a very difficult case. It seems that you have exhausted most options. Memantine seems to be worth trying at this point. Among other medications which you do not seem to mention are also the bisphosphonates, perhaps they may be considered in the future if memantine doesn't work.
I remain at your disposal for other questions.
Above answer was peer-reviewed by :
Dr. Chakravarthy Mazumdar
Answered by
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