Fatal poisoning by isoniazid and rifampicin
A 31-year-old male was brought with a history of vomiting, altered sensorium, and generalized tonic-clonic seizures, following ingestion of tablets of Isoniazid (9 gm) and rifampicin (6.75 gm). He was initially managed elsewhere and reached our emergency 32 h after ingestion. At presentation, patient was in shock, respiratory distress, and comatosed. He was immediately intubated and intravenous fluids and vasopressors support for shock was administered. Evaluation revealed orange and red color urine (no other features of red man syndrome), high anion gap metabolic acidosis due to lactic acidosis, rhabdomyolysis, renal, and hepatic dysfunction. Investigative work-up was tabulated []. We could not measure blood levels of Isoniazid and rifampicin because of non-availability and the diagnosis of poisoning was considered depending on history, used labeled drug strips, and clinical features. Initially, patient received acute peritoneal dialysis support for 28 h as he was in shock, and subsequently when his blood pressure improved he was changed over to sustained low efficiency dialysis (SLED) support. Patient also received oral pyridoxine (as intravenous preparation is not available) in almost equal quantity to the quantity of isoniazid ingested. Despite all efforts, patient succumbed after 4 days.