Old Akro,
Codral contains pseudoephedreine.
Side effects include dizziness and anxiety, he reported after landing that he had felt both.
The student's wife who is a doctor had told him not to take it. I wouldn't have done the lesson if he'd told me he had taken it. I can't take it before flying.
But hey what would I know, I'm just a dumb flying instructor who has survived 11,000 hours of students in various states of mental alertness.
My point was that non prescription medications are being more and more recognised as a cause of aircraft accidents.