Acute opioid withdrawl is characterized by -a) Rhinorrhoeab) Piloerectionc) Miosisd) Insomniae) Constipation
**Core Concept**
Acute opioid withdrawal is a complex physiological response to the sudden cessation or reduction of opioid use, involving multiple systems and neurotransmitter pathways. The body's attempt to adapt to the absence of opioid effects leads to a cascade of symptoms, primarily driven by the release of neurotransmitters that counteract the opioid's effects.
**Why the Correct Answer is Right**
The correct answer, piloerection, is a symptom of acute opioid withdrawal due to the activation of the sympathetic nervous system and the release of catecholamines, such as norepinephrine. This leads to increased heart rate, blood pressure, and vasoconstriction. Piloerection, or the formation of goosebumps, is a manifestation of the body's attempt to conserve heat and is mediated by the release of neuropeptide Y and other neurotransmitters that stimulate the pilomotor muscles.
**Why Each Wrong Option is Incorrect**
* **Option A:** Rhinorrhea (runny nose) is not a characteristic symptom of opioid withdrawal and is more commonly associated with upper respiratory tract infections or allergic reactions.
* **Option C:** Miosis (pupil constriction) is actually a characteristic of opioid use, not withdrawal, as opioids stimulate the parasympathetic nervous system to constrict the pupils.
* **Option D:** Insomnia is a common symptom of opioid withdrawal, but it is not as specific or unique to opioid withdrawal as piloerection, making it a less likely correct answer.
**Clinical Pearl / High-Yield Fact**
In acute opioid withdrawal, the body's sympathetic nervous system is activated, leading to increased heart rate, blood pressure, and vasoconstriction. This can be managed with medications such as clonidine, which helps to reduce symptoms by activating the parasympathetic nervous system and reducing the release of catecholamines.
**Correct Answer:** B. Piloerection