Oxycodone is an opioid. Experienced heroin users have described oxycodone as the “Rolls Royce” of opioids apparently because it produces a “smoother” high than heroin. Certain symptoms called opioid withdrawal symptoms may occur when an opioid is no longer ingested or when it is taken in smaller quantities , or when opioid is acutely displaced from its receptor by another drug with less activity at the opioid receptor.The severity of opioid withdrawal also can vary depending on individual differences(from opioid to opioid). It may also vary depending on what kind of hydrocodone your son has been using extended release or regular. Route of administration(oral/intravenous etc) also has an effect. In the least severe cases or early in withdrawal, symptoms may consist only of dysphoria, irritability, restlessness, and general achiness, with few objective signs. Signs and symptoms may be limited to craving, anxiety, dysphoria, yawning, perspiration(sweating), lacrimation(watering from eyes), rhinorrhea(watering from nose), and restless and broken sleep. In more severe cases or as the syndrome progresses, additional signs and symptoms that may be observed include increasingly dilated pupils, piloerection (waves of gooseflesh/erect hair), and hot and cold flashes with visible diaphoresis(sweating). In severe syndromes, the patient may also experience nausea, vomiting, diarrhea, weight loss, fever (usually low grade), and increased blood pressure, pulse, and respiratory rate. Also often observed are twitching of muscles(small muscle contractions and kicking movements of the lower extremities . Opioid withdrawal syndrome is not life threatening in healthy adults, most cases. However, deaths have occurred during abrupt opioid withdrawal in debilitated patients with other medical disorders. Decision on, whether detoxification should be done on inpatient or outpatient basis, differs from patient to patient.