I HAD A PATIENT Die Of Prolonged Seizure While On

I HAD A PATIENT die of prolonged seizure while on isoniazid and my research indicated that isoniazid could have been the cause as it depletes pyridoxine and this person was not on pyridoxine. I read pyridoxine is the antidote for prolonged seizures from INH but I cant seem to find the dose. Can you tell what dose of pyrdixone is recommended ? Also is there any stats on frequency of such seizures?