Algesia Overdosage

The clinical presentation of overdose may include the signs and symptoms of tramadol toxicity, paracetamol toxicity, or both.
Tramadol overdosage and management: Potential serious consequences of tramadol overdosage include respiratory depression, somnolence progressing to stupor or coma, skeletal muscle flaccidity, cold and clammy skin, constricted pupils, pulmonary edema (in some cases), bradycardia, hypotension, partial or complete airway obstruction, atypical snoring, seizures, cardiac arrest, and death. Death may occur within one hour of overdosage.
Deaths due to overdose with abuse and misuse of tramadol have been reported. Moreover, the risk of fatal overdose is further increased when tramadol is abused concomitantly with CNS depressants such as alcohol or opioids.
Primary attention should be given in re-establishing a patent and protected airway and maintaining adequate assisted or controlled ventilation, if needed. General supportive treatment (including oxygen and vasopressors) may also be employed in the management of circulatory shocks and pulmonary edema, as indicated. Naloxone may reverse some, but not all symptoms caused by tramadol overdosage. Serious arrhythmias or cardiac arrest will require advanced life-supporting measures.
Opioid antagonists (e.g., naloxone) should only be administered for the management of clinically significant respiratory or circulatory depression due to tramadol overdose. Although the administration of naloxone will only reverse some (but not all) symptoms caused by tramadol overdosage, it also increases the risk of seizure, for which intravenous diazepam may be given. In individuals who are physically dependent on opioids, the administration of an opioid antagonist should be started with care and by titration with smaller than usual doses of the antagonist to prevent the occurrence of acute withdrawal symptoms.
Since the duration of opioid reversal is expected to be less than the duration of action of tramadol, the patient should be carefully monitored until respiration normalizes.
Gastrointestinal decontamination with activated charcoal or by gastric lavage may also be performed within one to two hours of oral tramadol intoxication to remove any unabsorbed drug. Once the airway is protected, activated charcoal may be administered via nasogastric tube in patients who are not fully conscious or have impaired gag reflex. Gastrointestinal decontamination at a later time may only be useful in cases of overdosage with unusually large quantities.
Hemodialysis is not expected to be helpful for tramadol overdose because it only removes less than seven percent of the administered dose in a four-hour dialysis period.
Paracetamol overdosage and management: Overdosage of paracetamol usually involves four phases with the following signs and symptoms: Anorexia, nausea, vomiting, malaise, and diaphoresis; Right upper abdominal pain or tenderness, liver enlargement which may be characterized by abdominal discomfort of "feeling full", elevated bilirubin and liver enzyme concentrations, prolongation of prothrombin time, and occasionally oliguria; Anorexia, nausea, vomiting, and malaise recur and signs of liver (e.g., jaundice) and possibly kidney failure and cardiomyopathy may develop; Recovery or progression to fatal complete liver failure.
Potentially fatal hepatic necrosis is the most serious adverse effect. Renal tubular necrosis, hypoglycemic coma, thrombocytopenia, metabolic acidosis, and encephalopathy may also occur and may lead to coma and death. Although paracetamol does not normally produce methemoglobinemia or hemolysis even after overdosage or in patients with G6PD deficiency, there have been isolated reports of these complications. Clinical and laboratory evidence of hepatic toxicity may not be apparent 48 to 72 hours post-ingestion.
Emergency measures include: Immediate hospitalization.
A serum paracetamol assay to be obtained as soon as possible, but no sooner than four hours following oral ingestion.
Administer the antidote N-acetylcysteine (NAC) as early as possible by intravenous (IV) or oral route. In overdoses of oral paracetamol, NAC is administered, if possible, before the 10^th hour after ingestion of paracetamol. However, NAC may give some degree of protection from liver toxicity even after this time. As a guide to treatment of acute ingestion, the acetaminophen level can be plotted against time since oral ingestion on a nomogram (Rumack-Matthew). The lower toxic line on the nomogram is equivalent to 150 mcg/mL at four hours and 37.5 mcg/mL at 12 hours. If serum level is above the lower line, administer the entire course of NAC treatment. Withhold NAC therapy if the paracetamol level is below the lower line.
Symptomatic treatment.
Hepatic tests must be carried out at the beginning of treatment and repeated every 24 hours. In most cases, hepatic transaminases return to normal in one to two weeks with full restitution of the liver function. However, liver transplantation may be necessary in very severe cases.