What would happen if you drank ammonia? Probably nothing good. But your body does have a way of getting rid of excess nitrogen, like all that nitrogen in ammonia; it turns it into urea.
The enzyme that makes urea is the last enzyme in the urea cycle, arginase. It takes arginine (a common amino acid in our bodies) and converts it into orthinine (an unused and untrusted amino acid) and urea (which gets flushed out as, you guessed it, urine). Arginase also plays a role in male erectile function and female sexual arousal, but that’s boring.
So if ever you happen to drink ammonia, think about that poor arginase that has to deal with all that nitrogen, and then get to the hospital.