Rivastigmine (sold under the trade name Exelon) is a parasympathomimetic or cholinergic agent for the treatment of mild to moderate dementia of the Alzheimer's type and dementia due to Parkinson's disease. Rivastigmine, an acetylcholinesterase inhibitor, inhibits both butyrylcholinesterase and acetylcholinesterase (unlike donepezil, which selectively inhibits acetylcholinesterase). It is thought to work by inhibiting these cholinesterase enzymes, which would otherwise break down the brain neurotransmitter acetylcholine. Rivastigmine capsules, liquid solution, and patches are used for the treatment of mild to moderate dementia of the Alzheimer's type and for mild to moderate dementia related to Parkinson's disease. Rivastigmine has demonstrated treatment effects on the cognitive (thinking and memory), functional (activities of daily living) and behavioral problems commonly associated with Alzheimer's and Parkinson's disease dementia. In people with either type of dementia, rivastigmine has been shown to provide meaningful symptomatic effects that may allow patients to remain independent and ‘be themselves’ for longer. In particular, it appears to show marked treatment effects in patients showing a more aggressive course of the disease, such as those with younger-onset ages, poor nutritional status, or those experiencing symptoms such as delusions or hallucinations. Side effects may include nausea and vomiting, decreased appetite and weight loss.

Acquired myasthenia gravis (MG) is a chronic autoimmune disorder of the neuromuscular junction, characterized clinically by muscle weakness and abnormal fatigability on exertion. Current guidelines and recommendations for MG treatment are based largely on clinical experience, retrospective analyses and expert consensus. Pyridostigmine (under the trade names Mestinon (Valeant Pharmaceuticals)), has been used as a treatment for MG for over 50 years and is generally considered safe. It is suitable as a long-term treatment in patients with generalized non-progressive milder disease, and as an adjunctive therapy in patients with severe disease who are also receiving immunotherapy. Pyridostigmine inhibits acetylcholinesterase in the synaptic cleft by competing with acetylcholine for attachment to acetylcholinesterase, thus slowing down the hydrolysis of acetylcholine, and thereby increases efficiency of cholinergic transmission in the neuromuscular junction and prolongs the effects of acetylcholine. The side effects of Mestinon are most commonly related to over dosage and generally are of two varieties, muscarinic and nicotinic. Among those in the former group are nausea, vomiting, diarrhea, abdominal cramps, increased peristalsis, increased salivation, increased bronchial secretions, miosis and diaphoresis. Nicotinic side effects are comprised chiefly of muscle cramps, fasciculation and weakness. Muscarinic side effects can usually be counteracted by atropine, but for reasons shown in the preceding section the expedient is not without danger. As with any compound containing the bromide radical, a skin rash may be seen in an occasional patient. Such reactions usually subside promptly upon discontinuance of the medication.

Rivastigmine, (R)- is an impurity of a brain selective acetylcholinesterase inhibitor Rivastigmine. R-Rivastigmine enantiomer is pharmacologically less potent than S-enantiomer, which is used for the treatment of mild to moderate dementia of the Alzheimer's type and dementia due to Parkinson's disease.