A 54-year-old man is brought to the emergency department by police after he was found breaking into a food bank. He reports that he discovered a foolproof way to preserve food indefinitely and just needed to try it out on a larger supply. He states that this is too important to delay because it will end world hunger. He has a history of depression and anxiety. In the emergency department, he is alert and has rapid, pressured speech. He is fidgety and eager to get out of the hospital and to continue testing his product. His temperature is 37.5ºC (98.7°F), blood pressure is 129/84 mmHg, pulse is 98 beats/min, and respirations are 18 breaths/min. In addition to beginning lithium, therapy should be initiated with a medication targeting which …show more content…
The patient’s manic episode with underlying depression is consistent with bipolar disorder. Therapy for acute manic episodes includes initiation of a mood stabilizer like lithium as well as an atypical antipsychotic such as risperidone. Risperidone decreases positive symptoms like mania by inhibiting D2 dopamine receptors. D2 receptors in the mesolimbic pathway are thought to be responsible for psychotic episodes.
Choice "A" is not the best answer. Acetylcholine is a neurotransmitter at the neuromuscular junction and also a neurotransmitter in the autonomic nervous system. Acetylcholine is not affected by risperidone, nor is it related to acute mania.
Choice "C" is not the best answer. Glutamate is the primary excitatory neurotransmitter of the central nervous system, but is not associated with acute mania. Risperidone does not affect glutamate transmission.
Choice "D" is not the best answer. Risperidone has been shown to antagonize α-adrenergic receptors. This is partially responsible for the sedating effects of antipsychotics. However, adrenergic receptors are not responsible for acute manic episodes.
Choice "E" is not the best answer. Serotonin receptors are inactivated by risperidone, but these are not the primary neurotransmitters responsible for acute mania. Serotonin is primarily responsible for mood and is the target of most