The law AFAIK-
You don't have any legal obligation to answer questions from police. (you have the right to remain silent)
- You should provide your name and address though, as it might be an offence to withhold this in some cases.
Giving a police officer false information is an offence.
What I think -
I'd probably withhold the information if I didn't think it was necessary for them to know. I might gamble on telling them no, I'm not on any medication...depending on the circumstances, are they really going to subpoena medical records to find out? If I thought they might do this, I'd probably tell them. If they found out I was on medication, and I had told them I wasn't...I'd apologise and say I'm a bit nervous and didn't think of it. Are they going to charge me for this? I really doubt it. Could they? Technically they could.
If you think you might be searched, and you had methadone on you...it might be a better idea to just come out with it straight away.
I was riding a bike without a helmet one time and a police car flashed its lights at me. These guys were total arseholes, worst cops I've ever met (as I've mentioned a fair bit before I've had mostly good experiences with LE) They asked me why I didn't have my helmet (I forgot it) They asked for ID, and I told them I didn't have any on me (the truth) They see something in my pocket and ask me what it is, I pulled out my subutex that I had just picked up from the chemist. It confirmed my name but they got all suspicious once they heard 'subutex', wanted to know why I was on it. They ended up searching my name in their database and fining me something like $90 for no helmet...pretty sure they wouldn't have searched my name if the bupe wasn't involved. They then said to walk my bike home, they'd be coming down the street to check up on me (wtf), then when I was walking away they flicked their siren on for a second to scare the shit out of me, and I watched them drive off laughing.