Memantine manufacturers

MEMANTINE ANTIPARKINSON S DRUGS- AMANTADINE t CNS side-effects Additive effects on NMDA receptors Manufacturers recommend avoiding co-administration of amantadine and memantine... 

Memantine is predicted to interact with other drugs that use the same renal cationic transport system leading to increased levels of memantine and/or the other drug. The manufacturer lists cimetidine, ranitidine, hydrochlorothiazide, metformin, procainamide, qninidine, qninine and triamterene as possible examples. However, in an interaction study, the concurrent use of memantine and hydrochlorothiazide/triamterene did not result in any change in the steady-state AUC of memantine or triamterene, and the AUC of hydrochlorothiazide showed a modest reduction of about 20%. This degree of change is unlikely to be clinically relevant. Therefore, whether any clinically important interactions occur via this mechanism remains to be established. 

Memantine is chemically related to amantadine, and the manufacturer advises that concurrent use should be avoided or undertaken with caution because of the increased risk of adverse CNS-related drug reactions such as psychosis. Although there are no data, an increased risk is also predicted for ketamine and dextromethorphan, which are also NMDA antagonists. Avoidance of, or caution with, concurrent use is advised. 

The manufacturer of memantine notes that, although no causal relationship has been established, isolated cases of INR increases have been reported in patients treated with warfarin. They suggest close monitoring of anticoagulant effects. ... 

Yan, Y. Manufacture of memantine hydrochloride effervescent tablet for treating Alzheimer s disease. Faming ZhuanU Shenqing Gongkai Shuomingshu CN 1742711, 2006 Chem. Abstr. 2006, 144, 398290. 

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