Colchicina Seid Quá liều

Colchicine has a narrow therapeutic window and is extremely toxic in the event of overdose. Patients with hepatic or renal, gastrointestinal or cardiac disorders, and elderly patients show a high risk of overdose.
As colchicine overdose is complex, advice from a specialist experienced in overdose must be rapidly sought.
The exact dose of colchicine that causes significant toxicity is unknown. Deaths have been reported with doses as low as 7 mg over a period of four days, whereas there are cases where patients have survived doses of more than 60 mg.
A review of 150 patients with overdose showed that those receiving a dose of less than 0.5 mg/kg survived with a milder toxicity profile, whereas those receiving a dose of between 0.5 and 0.8 mg/kg experienced more severe reactions, including myelosuppression. The mortality in patients taking more than 0.8 mg/kg was 100%.
There may be a delay of up to 6 hours in the onset of toxicity, and some of the signs may even be delayed for more than one week. Therefore, any patient with suspected overdose must seek immediate specialised medical care, even in the absence of apparent signs.
The first signs of acute colchicine toxicity normally appear at around 24 hours post-administration. The most common symptoms include burning and discomfort in the mouth and throat, swallowing difficulties, digestive disorders such as nausea, vomiting, diffuse abdominal pain, tenesmus, severe diarrhoea, which may occasionally be bloody and lead to dehydration (metabolic acidosis) and circulatory disorders (hypotension), which together may lead to hypovolaemic shock. Peripheral leukocytosis has been observed on occasions.
The signs of toxicity after the first 24 hours and up to 7 days later include confusion, alopecia, cardiac disorders (including arrhythmia and decreased cardiac output), renal and hepatic impairment, respiratory distress, hyperpyrexia and bone marrow depression. These signs may progress to multiple organ failure associated with bone marrow aplasia, CNS toxicity, seizures, coma, hepatocellular damage, rhabdomyolysis, respiratory distress, renal and cardiac damage and disseminated intravascular coagulation. Death generally results from cardiorespiratory depression.
Patients who survive for 7 days post-overdose may present alopecia, rebound leukocytosis and stomatitis (around 10 days post-overdose).
TREATMENT: Treatment of colchicine overdose must include the use of oral activated charcoal for up to one hour in adults who have taken more than 0.1 mg/kg body weight of colchicine and in children who have taken any amount. A higher dose of activated charcoal may enhance systemic elimination and should be considered in patients who have taken more than 0.3 mg/kg body weight.
There is no specific antidote for colchicine. Gastric lavage may be considered. Haemodialysis and haemoperfusion do not enhance colchicine clearance. Management should include general symptomatic and supportive measures as indicated by the patient's clinical condition, including monitoring of vital signs, ECG, haematological and biochemical indices. Breathing may need assistance. Circulation should be maintained and fluid and electrolyte imbalance corrected.
Morphine sulphate 10 mg may be given intramuscularly to relieve severe abdominal pain.
To allow for managing the delayed onset of symptoms, patients should be carefully monitored for at least 6 hours post-administration, or for 12 hours if they have taken more than 0.3 mg/kg. After this time, asymptomatic patients may be discharged with advice to return if gastrointestinal symptoms appear.