1. A patient diagnosed with Parkinson's disease is prescribed Levodopa/Carbidopa. Which of the following is a primary reason for combining these two medications? A. Carbidopa crosses the blood-brain barrier to increase dopamine synthesis. B. Levodopa enhances the action of Carbidopa in the peripheral tissues. C. Carbidopa prevents the peripheral breakdown of Levodopa, increasing its availability in the brain. D. Levodopa and Carbidopa together decrease the risk of neuroleptic malignant syndrome. Answer: C. Carbidopa prevents the peripheral breakdown of Levodopa, increasing its availability in the brain. Rationale: Carbidopa does not cross the blood-brain barrier and is combined with Levodopa to inhibit its peripheral metabolism, allowing more Levodopa to reach the brain where it is converted to dopamine. 2. A nursing student is asked about the mechanism of action of SSRIs in treating depression. Which of the following should be included in their explanation? A. SSRIs selectively block the reuptake of serotonin, increasing its concentration in the synaptic cleft. B. SSRIs decrease the production of serotonin, thus stabilizing mood fluctuations. C. SSRIs enhance the degradation of serotonin, leading to increased receptor sensitivity. D. SSRIs block the postsynaptic receptors, preventing serotonin binding. Answer: A. SSRIs selectively block the reuptake of serotonin, increasing its concentration in the synaptic cleft. Rationale: SSRIs, or selective serotonin reuptake inhibitors, work by blocking the reabsorption (reuptake) of serotonin in the brain, making more serotonin available to improve transmission of messages between neurons. [...Continued with similar structure for remaining questions...] 15. When considering the pharmacological treatment of bipolar disorder, a nurse should understand that mood stabilizers such as lithium are used primarily for which purpose?