Which drug is specifically used as a reversible AChE inhibitor for managing chronic myasthenia gravis symptoms?

Pyridostigmine is specifically used as a reversible acetylcholinesterase (AChE) inhibitor for managing the symptoms of chronic myasthenia gravis due to its pharmacokinetic properties and duration of action. It works by inhibiting the enzyme AChE, which breaks down acetylcholine in the synaptic cleft, ultimately increasing the levels of acetylcholine available to stimulate the postsynaptic receptors at the neuromuscular junction. This enhances muscle contraction and alleviates the muscle weakness characteristic of myasthenia gravis.

Pyridostigmine has a longer duration of action compared to similar drugs like neostigmine, making it more suitable for chronic management of the condition. Its effectiveness in enhancing neuromuscular transmission makes it the drug of choice in this scenario.

Other drugs listed, while they are reversible AChE inhibitors, are used for different indications. Neostigmine, although also an AChE inhibitor, is more often utilized in the management of myasthenic crises or for reversing neuromuscular block in the context of anesthesia, making it less ideal for chronic management compared to pyridostigmine. Donepezil and rivastigmine are