Acetylcholine (ACh) is a neurotransmitter key in an individual’s ability to adapt to his/her environment and surrounding stimuli. ASD patients show many deficits in ACh production and receptor function. Acetylcholinesterase is an enzyme involved in the degradation of acetylcholine. Anticholinesterase inhibitors, or acetylcholinesterase inhibitors (AChE-inhibitors), seek to block the action of this enzyme, thus increasing ACh levels and action durations. Examples that have been tested and shown beneficial effects in ASD patients include rivastigmine, donepezil, and galantamine. Improvements in expressive speech are consistent across the drugs. Reports also include improvements in irritability, hyperactivity, receptive language, social withdrawal, inattention, and anger management. Side-effect profiles include diarrhea, nausea, and vomiting. Currently AChE-inhibitors are some of the most promising class of drugs in...