<prompt> Symptom of opioid withdrawal is:PiloerectionDry SkinBradycardiaPupillary construction  <response>: Ans. A. PiloerectionOpioid Withdrawal With long-term use of opioids down regulation of dynorphins, endogenous endorphins and opioid receptors takes place. Abrupt cessation of opioid use does not allow time for upregulation of receptors It results in elevated neuronal firing and the opioid withdrawal syndrome. Opioid withdrawal usually starts with-- Diaphoresis- Yawning- Feelings of anxiety- Lacrimation- Rhinorrhea and diffuses myalgias.It then progresses to -- Nausea- Profuse vomiting- Diarrhea, Piloerection, mydriasis and abdominal dehydration. Opioid withdrawal reactions are not life-threatening and rarely fatal but they are very uncomfortable. Vomiting and aspiration of gastric contents causes pneumonitis. 