Tacrine hydrochloride

Tacrine is the first therapeutic launched specifically for the treatment of Alzheimer's disease which affects four million people in the US alone. Clinically significant improvement in cognition has been demonstrated in the patients with Alzheimer's disease. Although the cause of Alzheimer's disease is not understood, degeneration of cholinergic neurons is thought to be a primary factor in the development and progression of the disease. Tacrine is a reversible acetylcholinesterase inhibitor that presumably acts centrally by elevating the acetylcholine level in the cerebral cortex and by slowing degradation of acetylcholine from intact cholinergic neurons. While tacrine improves the symptoms of Alzheimer's disease, the underlining cause of the dementing process is not altered. It has also been suggested that the beneficial effects of tacrine may be due to its multiple effects on several neurotransmitter systems.

Tacrine is a derivative of aminoacridine that functions as an inhibitor of both acetylcholinesterase (AChE) and butyrylcholinesterase (IC₅₀s = 31 and 26.5 nM, respectively). Tacrine also inhibits the uptake of serotonin and norepinephrine in rat cerebral cortex and decreases depolarization-induced calcium influx through L-type calcium channels in SN56 neuronal cells. Formulations containing tacrine have been used clinically in the treatment of Alzheimer’s disease.

Pale Yellow Solid

NIH (U.S.A.)

A potent centrally acting anticholinesterase, for therapy of memory deficits in patients with Alzheimers disease. THA also selectively blocks potassium channels in the central nervous system, which results in an increased release of acetylcholi

A potent centrally acting anticholinesterase for therapy of memory deficits in patients with Alzheimer's disease. THA also selectively blocks potassium channels in the central nervous system, which results in an increased release of acetylcholine and a prolongation of the action potential of the presynaptic cholinergic neurons.

anticholinesterase, cognitive adjuvant, K channel blocker

Cognex (Sciele).

Tacrine hydrochloride,1,2,3,4-tetrahydro-9-aminoacridine hydrochloride (THA,Cognex), is a reversible cholinesterase inhibitor that hasbeen used in the treatment of Alzheimer disease for severalyears. The drug has been used to increase the levels of AChin these patients on the basis of observations from autopsiesthat concentrations of ChAT and AChE are markedly reducedin the brain, whereas the number of muscarinic receptorsis almost normal. The use of the drug is not withoutcontroversy, as conflicting results on efficacy have been reported.The drug has been used in mild-to-moderateAlzheimer dementia.

Yellow needles (from concentrated hydrochloric acid); white powder. pH of 1.5% solution: 4.5-6. Bitter taste.

Water soluble.

TACRINE HYDROCHLORIDE is incompatible with strong oxidizing agents, acid chlorides and acid anhydrides . Neutralize bases in slightly exothermic reactions.

Flash point data for TACRINE HYDROCHLORIDE are not available; however, TACRINE HYDROCHLORIDE is probably combustible.

Potent cholinesterase inhibitor, a cognition enhancer in vivo .

Tacrine is extensively metabolized by CYP450 to at least three metabolites. The major metabolite, 1-hydroxy-tacrine, is active. Its elimination half-life is between 1.5 and 4 hours, with metabolites being are excreted via the urine.

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