Single intravenous doses of 1 to 2 mg zinc/kg body weight have been given to adult leukemic patients without toxic manifestations. However, acute toxicity was reported in an adult when 10 mg zinc was infused over a period of one hour on each of four consecutive days. Profuse sweating, decreased level of consciousness, blurred vision, tachycardia (140/min), and marked hypothermia (94.2° F) on the fourth day were accompanied by a serum zinc concentration of 207 mcg/dl. Symptoms abated within three hours.
Hyperamylasemia may be a sign of impending zinc overdosage; patients receiving an inadvertent overdose (25 mg zinc/liter of total parenteral nutrition solution, equivalent to 50 to 70 mg zinc/day) developed hyperamylasemia (557 to 1850 Klein units; normal: 130 to 310).
Death resulted from an overdosage in which 1683 mg zinc was delivered intravenously over the course of 60 hours to a 72-year-old patient.
Symptoms of zinc toxicity included hypotension (80/40 mm Hg), pulmonary edema, diarrhea, vomiting, jaundice, and oliguria, with a serum zinc level of 4184 mcg/dl.
Calcium supplements may confer a protective effect against zinc toxicity.