Metronidazole and Alcohol - how much can you have?

So antibiotics eey? The long standing tradition of not drinking while on antibiotics has come a reality this week.
In my quest to resume tradition of another booze fuelled weekend, I did a little research on this, as I originally thought that alcohol would inhibit the antibiotics, rendering them useless and therefore the course of medication is irrelevant. And the infection comes back and eats not only your healthy cells, but also your cat, TV, laptop AND drinking suit.

It appears that drinking does indeed change the effectivity of antibiotics, but not to such an extent where they stop working - the main worry is nausea, extreme vomiting and other fun effects - but it really does depends on what antibiotics you are on.

The first, err what's it called - Amoxicillin, is a penicillin based antibiotic - and is not really affected by the intake of alcohol. Drinking just after taking it isn't advised, but this is only because it can adversely affect the absorption into the stomach and digestive system - as with anything. So no actual reaction between the two.

Metronidazole however is a different kettle of fish. This can cause nausea, massive vomiting and tachycardia. So I wonder why?
It's something to do with limiting the body's ability to break down and metabolise the alcohol - by blocking the breakdown of propylene glycol in the liver. This increases the amount of propylene glycol in the blood, and can harm the liver and other fun items in the body that allow life to happen.

So it makes propylene glycol stay in my body for ages, so what does this do? Well it looks like it's used in loads of household goods, from deoderant sticks to being a moisturiser in cosmetics. It's even a safe food additive in the US (not checked other countries..) - However this method of ingestion (oral) is minimally effective, and is therefore deemed quite safe - but when propylene glycol is allowed into the bloodstream, intravenously as it were, it becomes quite dangerous.

To make use of this and try to find out how much booze I can actually consume before the propylene glycol becomes fatally toxic, I need to find out the fatal dose... for which there is no data.

Absorption rates in rats after ingestion is 90-100%, usually not building up in the body. But when breakdown is inhibited this could build up quickly.

Ingestion of a sufficient quantity can definitely cause death. 1g per KG of body weight, so say 90g of this stuff can affect the central nervous system, causing numbness, visual distortions etc.... Increase this to 3g/kg, and you get massively drunk, slurred speech and stupor/agitation mental state shifts.
Over that, you get coma, loss of reflexes and probably death.

So it's quite inconclusive unless data on how much of this stuff is held back by the body.

All of the above sounds like getting pissed anyway, but I don't think I will booze on during the course of these antibiotics. I will find out tomorrow.