Clinical experience with acute Didronel overdosage is extremely limited. Decreases in serum calcium following substantial overdosage may be expected in some patients. Signs and symptoms of hypocalcemia also may occur in some of these patients. Some patients may develop vomiting. In one event, an 18-year-old female who ingested an estimated single dose of 4000 to 6000 mg (67 to 100 mg/kg) of Didronel was reported to be mildly hypocalcemic (7.52 mg/dl) and experienced paresthesia of the fingers. Hypocalcemia resolved 6 hours after lavage and treatment with intravenous calcium gluconate. A 92-year-old female who accidentally received 1600 mg of etidronate disodium per day for 3.5 days experienced marked diarrhea and required treatment for electrolyte imbalance. Orally administered etidronate disodium may cause hematologic abnormalities in some patients (see ADVERSE REACTIONS).
Etidronate disodium suppresses bone turnover and may retard mineralization of osteoid laid down during the bone accretion process. These effects are dose and time dependent. Osteoid which may accumulate noticeably at doses of 10 to 20 mg/kg/day of chronic, continuous dosing mineralizes normally posttherapy.
Prolonged continuous treatment (chronic overdosage) has been reported to cause nephrotic syndrome and fracture.
Gastric lavage may remove unabsorbed drug. Standard procedures for treating hypocalcemia, including the administration of Ca++ intravenously, would be expected to restore physiologic amounts of ionized calcium and relieve signs and symptoms of hypocalcemia. Such treatment has been effective.