Modafinil is a pretty common drug prescribed for a wide range of issues, it doesn't have wild sudden side effects, it won't make you go suddenly crazy, erratic or cloud your judgement, it's essentially between a very strong coffee and a very weak amphetamine.

+Plenty of people get prescribed medicine and go to work the next day even if they never tried it.

You never know if you'll have adverse reactions, even if it's safe for most people.

I have a good friend (who is otherwise reacting normally to stimulants) who took IIRC ~50mg of Modafinil for the first time for an exam in uni. They ended up having to go to the ER in the middle of the exam, got diagnosed with some form of allergic reaction. Doc said it can happen for many medications.

Whenever trying a new substance for the first time, do so in a way and context that minimizes impact of unexpected effects or adverse reactions.

So I agree OP was irresponsible and should at the minimum have taken one dose off work before their first work-day on it.

Would you say the same thing if it was the person's first time with caffeine? Because Modafinil is a stimulant and used to treat narcolepsy, one could argue that going to work tired and treating people would have been more dangerous. I agree with you that he definitely should have done it prior but this is relatively low on my scale of recklessness. It is not like the effects weren't known. Just the severity of his reaction.

Entirely different. Caffeine is a very well studied substance with widely known effects, it has been used for literally centuries by a sizeable portion of the human population.

This is also a studied substance with known side effects. The author mentioned looking into the literature for clinical data before purchasing.

And in modern day, we have FDA, which is a very-tough-to-get-by filter for public medication.

The FDA has decided that this a substance the needs restricting from general consumption for a reason wrong or no. Was that the right decision or wrong I don't know. But I have to assume they have some reason but it would be enough for me to take seriously the possible consequences of having a adverse reaction when dealing with the lives of OTHER PEOPLE if he had started his self experiment on his own time that would be one thing but he was treating other people and that makes this inexcusable. had he tried it in a safe controlled situation, then determined it to be safe and used it at work then I wouldn't care but he didn't. bottom line he put other people at risk.

Your statement is essentially "given OPs current state and prior probability of him making a mistake on the job, and the action of taking modafinil, that probability increases given the OP takes that action.

Which is not an accurate statement.

Modafinil is a nootropic, which means that it can increase attention, therefore decreasing the chance of a mistake. The probability that someone will experience more wakefulness and attention is high in this regard.

And it being FDA approved lowers the probability of an adverse reaction that can cause someone to not be in the right mind and make mistakes to a very small number, which accounts for things like heart conditions.

To be fair this isn't some unknown substance and the author clearly did their homework, looking into personal accounts and reading clinical studies.

Doing drugs doesn’t make you irresponsible. Caffeine is a drug, is drinking coffee irresponsible? I’d argue it’s more responsible to browse Erowid’s reports and see drugs’ effects before trying them out, rather than doing something and not knowing anything about it.