Discontinuation of which of the following drugs can result in anxiety and insomnia?
**Core Concept**
The question is testing the concept of drug withdrawal or discontinuation syndrome, which refers to a set of symptoms that occur when a person stops taking a medication that they have been taking for a prolonged period. This can lead to rebound effects, where the body tries to compensate for the loss of the medication's effects, resulting in symptoms such as anxiety and insomnia.
**Why the Correct Answer is Right**
The correct answer is likely a benzodiazepine, such as alprazolam (Xanax) or clonazepam (Klonopin). When benzodiazepines are taken regularly, the body adapts by changing the way it regulates the neurotransmitter GABA (gamma-aminobutyric acid), which is involved in calming down the nervous system. When the medication is stopped abruptly, the body is unable to produce enough GABA to calm the nervous system, leading to symptoms such as anxiety and insomnia.
**Why Each Wrong Option is Incorrect**
**Option A:** Opioids, such as morphine or fentanyl, can cause withdrawal symptoms such as anxiety and insomnia, but the primary symptoms are more likely to be pain, diarrhea, and vomiting.
**Option B:** Antidepressants, such as selective serotonin reuptake inhibitors (SSRIs), can cause withdrawal symptoms such as dizziness and headaches, but are less likely to cause anxiety and insomnia.
**Option C:** Antihistamines, such as diphenhydramine (Benadryl), can cause drowsiness and sedation, but are less likely to cause anxiety and insomnia as withdrawal symptoms.
**Clinical Pearl / High-Yield Fact**
When discontinuing benzodiazepines, it's essential to taper off the dose gradually to minimize the risk of withdrawal symptoms. A general rule of thumb is to reduce the dose by 25-50% every 2-4 weeks to allow the body to adapt.
**Correct Answer:** C.