My friend has a high tolerance with cocaine so he decided to iv it I'm assuming he took too much after hours of iv he took a a big amount mind you this is coke is is top quality but he said after the he took the big injection he immediately felt some sort of ringing in his ears and felt really good at the same time maybe too good but also his legs felt weak The ringing is gone but my question is what caused it my guess is he almost OD. What's your thoughts