What happens if you take too much of hydroxychloroquine?

Plaquenil (hydroxychloroquine): Toxicity can show hearing & hair loss, convulsions, liver damage.

Over dose: Per Drugs.Com an overdose of Hydroxychloroquine can cause "drowsiness, vision changes, seizure, slow heart rate, weak pulse, pounding heartbeats, sudden dizziness, fainting, shortness of breath, or slow breathing (breathing may stop)." REF: https://www.drugs.com/hydroxychloroquine.html