Description
In the 1950s, tacrine was used experimentally to reverse
cholinergic coma in animals. In the 1960s, tacrine was used to
reverse the effects of phencyclidine-like drugs. It was also
marketed for many years as a respiratory stimulant. In 1993,
the US Food and Drug Administration approved tacrine for the
treatment of symptoms of mild to moderate Alzheimer’s
disease.
Uses
The current use of tacrine is limited due to its poor oral
bioavailability, the necessity for four daily doses, and serious
side effects (including nausea, vomiting, dry mouth, indigestion,
diarrhea, loss of appetite, urinary incontinence, collapse,
convulsions, and hepatotoxicity). Currently, newer cholinesterase
inhibitors (such as donepezil, rivastigmine, and galantamine)
are preferred over tacrine.
Definition
ChEBI: Tacrine is a member of the class of acridines that is 1,2,3,4-tetrahydroacridine substituted by an amino group at position 9. It is used in the treatment of Alzheimer's disease. It has a role as an EC 3.1.1.7 (acetylcholinesterase) inhibitor. It is a member of acridines and an aromatic amine. It is a conjugate base of a tacrine(1+).
Toxicity evaluation
Tacrine has numerous mechanisms of action. The putative
principal mechanism of action of tacrine for Alzheimer’s
disease is reversible inhibition of acetylcholinesterase (AChE),
which thereby slows the breakdown of the chemical messenger
acetylcholine (ACh) in the brain. Tacrine also inhibits butyrylcholinesterase
activity. In addition, tacrine blocks sodium
and potassium channels. Tacrine also acts as a histamine
N-methyltransferase inhibitor.
At a therapeutic dose, tacrine causes liver toxicity. Cytotoxicity
studies using the human liver cell line HepG2 showed that
a therapeutic blood concentration of tacrine induces reactive
oxygen species production and glutathione depletion, suggesting
that oxidative stress might be involved in tacrine
hepatotoxicity.
