hypocalcemia

I've never heard of hypercalcemia, but I have heard of osteoporosis, which I assume is caused by hypocalcemia.

Laboratory studies revealed thrombocytopenia, hyponatremia, hyperkalemia, hypochloremia, hypocalcemia, acute renal insufficiency, and acute liver injury.

I don't know the precise mechanism for toxicity (I thought it was hypocalcemia), but if the tradionally safety-lax academia takes HF that seriously, you know it's the real deal.

Systemic effects: If left untreated, hydrofluoric acid poisoning can lead to systemic effects such as hypocalcemia (low blood calcium levels), hypomagnesemia (low blood magnesium levels), and hyperkalemia (high blood potassium levels), which can cause cardiac arrhythmias and death.

Use hydroxychloroquine with caution in patients with conditions that may increase the risk of QT prolongation including congenital long QT syndrome, bradycardia, AV block, heart failure, stress-related cardiomyopathy, myocardial infarction, stroke, hypomagnesemia, hypokalemia, hypocalcemia, or in patients receiving medications known to prolong the QT interval or cause electrolyte imbalances.