Ambenonium is a cholinesterase inhibitor used in the management of myasthenia gravis. [Wikipedia]
Indication
Ambenonium is used to treat muscle weakness due to muscle disease (myasthenia gravis).
Pharmacology
Ambenonium, similar to pyridostigmine and neostigmine, is used for the treatment of muscle weakness and fatigue in people with myasthenia gravis. It is postulated to exert its therapeutic effect by enhancing cholinergic function through the inhibition of the acetylcholine hydrolysis by acetylcholinesterase. Increased levels of acetylcholine has peripheral effects, as acetylcholine is also used in the brain, where it tends to cause excitatory actions. The glands that receive impulses from the parasympathetic part of the autonomic nervous system are also stimulated in the same way. This is why an increase in acetylcholine causes a decreased heart rate and increased production of saliva. Ambenonium is used less commonly than neostigmine or pyridostigmine but may be preferred in patients hypersensitive to the bromide ion. Ambenonium produces fewer muscarinic side effects than neostigmine, but more than pyridostigmine.
Toxicity
LD50=150±44 mg/kg (orally in mice). Symptoms of overdose include muscle twitching, weakness and paralysis of voluntary muscles including the tongue, shoulders, neck and arms, blood pressure increase (with or without a slowing of heart rate), a sensation of internal trembling, severe anxiety, and panic. Death may occur rapidly if untreated.
Affected Organisms
Humans and other mammals
Biotransformation
Plasma and hepatic
Absorption
Oral - poorly absorbed from the gastrointestinal tract.