Which of the following best describes a current working hypothesis about the molecular mechanism of action of lithium?

Correct Answer: A

Rationale: The correct answer is A. Increased synthesis of adenylyl cyclase. One of the leading hypotheses about the molecular mechanism of action of lithium is its ability to increase the synthesis of adenylyl cyclase. Adenylyl cyclase is an enzyme involved in the production of cyclic adenosine monophosphate (cAMP), which plays a role in cellular signaling pathways. By increasing the synthesis of adenylyl cyclase, lithium may help to regulate intracellular signaling and neurotransmitter release, contributing to its mood-stabilizing effects in bipolar disorder.

Correct Answer: B

Rationale: In this scenario, the correct answer is B) Aripiprazole. Aripiprazole is an atypical antipsychotic that is commonly used to treat conditions like Tourette syndrome, which presents with symptoms of repeated head jerking, blinking, and grimacing. Aripiprazole works by modulating dopamine and serotonin receptors in the brain, helping to reduce the frequency and severity of these involuntary movements. Option A) Fluoxetine is a selective serotonin reuptake inhibitor (SSRI) commonly used to treat depression and anxiety disorders. While it may help with some symptoms associated with Tourette syndrome, it is not the first-line treatment for the specific symptoms described in the question. Option C) Clonazepam is a benzodiazepine that is often used to treat seizures and anxiety disorders. While it may help with some symptoms of Tourette syndrome, it is not the primary medication used to address the specific symptoms of repeated head jerking, blinking, and grimacing. Option D) Naltrexone is an opioid receptor antagonist primarily used to treat alcohol and opioid dependence. It is not indicated for the treatment of movement disorders like Tourette syndrome. Educationally, understanding the mechanisms of action and indications of different drug classes is crucial for nursing practice. By knowing which medications are appropriate for specific conditions, nurses can provide safe and effective care to their patients. In this case, recognizing that aripiprazole is the preferred choice for treating Tourette syndrome symptoms can lead to improved patient outcomes and quality of life.

Correct Answer: C

Rationale: Bupropion is a medication that is commonly used to treat depression, ADHD, and smoking cessation. Given the woman's symptoms of feeling fearful, helpless, and worried, as well as her difficulty organizing thoughts and smoking habit, bupropion would be a suitable choice as it can address both depressive and attention deficit disorders, as well as aid in smoking cessation.

Correct Answer: D

Rationale: The opening of K+ channels on postsynaptic neurons is a key molecular action that mediates the analgesic effect of opioids like morphine. This action leads to hyperpolarization of the neuron, reducing its excitability and inhibiting pain transmission. Therefore, in a patient with severe pain due to multiple fractures, the opening of K+ channels by morphine would be the most likely mechanism responsible for the analgesic effect.

Correct Answer: D

Rationale: The patient self-injected what he believed to be heroin, which is commonly sold on the street. Fentanyl is a potent synthetic opioid that is often mixed with or sold as heroin due to its powerful effects. Therefore, the patient most likely took Fentanyl, as it is frequently associated with street drugs like heroin.