Memantine Ketamine

Antagonists L-AP3 MK-801 Memantine Ketamine Dextrophan CPP 7-CK (glycine site) CNQX NBQX LY382884... 

NMDA antagonists The combined use of memantine with other NMDA antagonists (amantadine, ketamine, and dextromethorphan) has not been systematically evaluated. Approach such use with caution. 

Memantine (Namenda) [Anti Alzheimer Agent/NMDA Receptor Antagonist] Uses Mod/ evere Alzheimer Dz Action N-methyl-D-aspartate recqjtor antagonist Dose Target 20 mg/d, start 5 mg/d, t 5 mg/d to 20 mg/d, wait >1 wk before t dose use doses if >5mg/d Caution [B, /-] Hqjatic/mild-mod renal impair Disp Tabs, sol SE Dizziness Interactions t Effects W amantadine, carbonic anhydrase inhibitors, dextromethorphan, ketamine, Na bicarbonate t effects W/ any drug, herb, food that alkalinizes urine EMS Use NaHCOs w/ caution OD May cause restlessness, hallucinations, drowsiness, and fainting symptomatic and supportive... 

Arendtnielsen L, Petersenfelix S, Fischer M, et al (1995) The effect of N-methyl-o-aspartate antagonist (ketamine) on single and repeated nociceptive stimuli a placebo-controlled experimental human study. Anesth Analg 81 63-68 Areosa SA, Sherriff F (2003) Memantine for dementia (Cochrane Review). Cochrane Database Syst Rev 1 CD003154... 

Snznki R, Matthews EA, Dickenson AH (2001) Comparison of the effects of MK-801, ketamine and memantine on responses of spinal dorsal horn nenrones in a rat model of mononenropathy. Pain 91 101-109... 

A putative back-up of this structural class might be AR-R-15,896 which is at least in preclinical development by AstraZeneca (company communication). Compared to ketamine and memantine, AR-R-15,896 might have more favorable pharmacodynamic features (Mealing et al.,... 

Davidson, E. M. and Carlton, S. M. Intraplantar injection of dextrorphan, ketamine, or memantine attenuates formalin-induced behaviors, Brain Res. 1998, 785, 136-142. 

In a double-blind, randomized, placebo-controlled crossover comparison of the effects of ketamine and memantine in 15 male volunteers, ketamine increased serum prolactin and cortisol concentrations, whereas memantine and placebo did not (582). 

Hergovich N, Singer E, Agneter E, Eichler HG, Graselli U, Simhandl C, Jilma B. Comparison of the effects of ketamine and memantine on prolactin and cortisol release in men. a randomized, double-blind, placebo-controlled trial. Neuropsychopharmacology 2001 24(5) 590-3. 

Ketamine is chemically related to other dissociative anesthetics, including dextromethorphan (DXM), found in some over-the-counter cough syrups, and nitrous oxide (often called whippets ). Ketamine also shares a close chemical kinship to the prescriptives tiletamine and memantine. Tiletamine is used in combination with zolazepam as a veterinary anesthetic under the brand names Zoletic and Telazol. 

MEMANTINE ANAESTHETICS -GENERAL-KETAMINE t CNS side-effects Additive effects on NMDA receptors Avoid co-administration... 

Fazidinium bromide Fenoterol hydrobromide Folic acid Halothane Ifenprodil tartrate Ketamine HCI Memantine Metaproterenol Norfenefrine Oxaflozane HCI Phendimetrazine tartrate Phentermine HCI Procarbazine HCI Promegestone Pyrovalerone HCI Sulfacytine Sulfaiene Trioxsalen N-Bro moaceta m Ide Fluazacort... 

Drugs that make the urine alkaline (e.g. sodium bicarbonate, carbonic anhydrase inhibitors) will reduce the elimination of memantine. Memantine should be used with caution with other NMDA antagonists, such as amantadine, ketamine and dextromethorphan, or concurrent use should be avoided, because of the theoretical increased risk of adverse effects. Memantine is predicted to interact with other drugs eliminated by the same renal secretion mechanism, but no important interaction was seen with glibenclamide, hydrochlorothiazide, metformin or triamterene. 

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. 

Grande LA, O Donnell BR, Fitzgibbon DR, Terman GW. Ultra-low dose ketamine and memantine treatment for pain in an opioid-tolerant oncology patient. Int Anesth Res Socy 2008 107(4). 

Ketamine is one of the most widely known and medically used NMDA receptor antagonists (NMDAR) and memantine is similar in that it is a noncompetitive NMDA antagonist but is better tolerated in patients because of multiple theorized properties including the ability to bind only (or preferentially) to open channels the tendency to inhibit faster, or with higher affinity, at higher agonist concentration a relatively low affinity of inhibition being an open channel blocker with a fast off-rate compared with ketamine [1,2]. 

Ketamine causes memory deficits reproduces with impressive accuracy the symptoms of schizophrenia is widely abused and induces vacuoles in neurons at moderate concentrations and cell death at higher concentrations. Memantine, on the other hand, is well tolerated although instances of psychotic side effects have been reported, in placebo-controlled chnical studies the incidence of side effects is remarkably low. Memantine improves memory in Alzheimer dementia patients and in some (but not all) studies in animals [1]. 

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