Overdose : מינון יתר

4.9.   Overdose
Symptoms of Overdose
Literature describes symptoms of intoxication upon absorption of more than 10 g of povidone-iodine.

Acute iodine toxicity is manifested by abdominal symptoms like nausea, vomiting, diarrhea, dehydration, blood pressure drop, bleeding tendency (mucous membranes, kidneys), cyanosis, anuria, circulatory collapse, pulmonary edema and metabolic disorders.

Upon prolonged excessive exposure with iodine, symptoms of hyperthyroidism, tachycardia, unrest, tremor and headache may occur.

Systemic toxicity may result in renal dysfunction (including anuria), paresthesia, tachycardia, hypotension, circulatory failure, glottis edema causing asphyxia or pulmonary edema, seizures, fever and metabolic acidosis. Hyperthyroidism or hypothyroidism may also develop.



Management of Overdose:
Treatment is symptomatic and supportive.

In case of severe hypotension intravenous fluid is to be administered and additional vasopressors should be administered if needed.

Endotracheal intubation may be required, if a caustic injury of the upper airways causes significant swelling and edema.

Vomiting should not be induced. The patient is to be kept in a position keeping the airways patent and preventing aspiration (in the case of vomiting).

If the patient does not vomit and oral nutrition is possible, the intake of starchy foodstuffs (e.g., potatoes, flour, bread) may support the conversion of iodine to the less toxic iodide. If no signs of intestinal perforation are seen gastric lavage with starch solution (5% sodium thiosulfate solution (or 10 ml sodium thiosulfate IV) at intervals of 3-hours) may be given via a nasogastric probe (the gastric discharge will show a dark-blue/purple discoloration which may be used as an indication, when the lavage may be terminated).

Haemodialysis will effectively flush out iodine and should be used in severe cases of iodine intoxication, especially in the presence of renal failure.
Continuous venovenous hemodiafiltration will be less effective than hemodialysis.

In the case of a thyroid dysfunction treatment with povidone-iodine should be discontinued

Moreover, close clinical monitoring of thyroid function is indicated to allow exclusion or early diagnosis of potential hyperthyroidism.

Further management will depend on the presence of any other potential symptoms such as metabolic acidosis and renal dysfunction.