Taking Prescription drugs through airport customs

I don't imagine that it really matters that you do not have a valid, current prescription. The prescription is usually surrendered to the Pharmacist to be filled anyway. He/she doesn't give it back to you. They take the information, prepare your prescription, print the label and file your original prescription. The only concern will be that the medications are in their own originally labelled container. They do still have the label on, right? You could get your Doctor to type up a letter for you detailing the medication you take, the dose, method etc. I always carry one, just incase.
They don't generally take away anyone's medication if you have a valid reason & is labelled properly by a pharmacist with your name on it. Not unless it is a controlled substance or illegal in the country.

I would strongly suggest that you do NOT put your meds in your checked bag. You may need your medication during the flight. What if your luggage is lost, stolen or delayed? Always keep your meds in your carry-on.

Customs checks heading into Europe are very rare. The problems arises when you head back home into the US. US Customs is more strict. Heading home I would not be in possession of any medication that I didn't have a valid prescription. If they decided to hand search you and your luggage and find this medication there is the possibility you could go to jail. If its hay fever medication they may simply confiscate it, if its pain killers you could easily be charged with a felony. It's alway best to comply with the law.

Never put meds in checked luggage. That is so dangerous, if meds are in fact medically nessesart go to a doctor and have a letter written. If you can afford a trip to europe you can afford to spend 100 dollars to do this right. I think it is sad that in the States you have to resort ot mail order drugs and no doctors supervision and you apparently have a medical condition that warrants a TWO prescription drugs.
Good luck, chances are a customs offical would not take drugs,( especially for high blood pressure or diabetes, but,if they are unlabeled Valium or narcotic painkillers you may run into problems, and frankly, , you should be under a doctors care anyways.

Take the amount you need plus two days worth and leave the rest at home.

I have never had any medication checked by officials. I do always carry anything I have in the original containers and if it is prescription keep it in it's original packet with the pharmacy label in tact. If you are really concerned you could go and see your doctor and get a letter from him/her saying they are necessary medications. Wow if a doctor's visit is $100 in the US, makes our health care system seem almost perfect. Costs us $50.00 with $22.00 claimed back through national health care scheme or is free is you are disadvantaged.

Upon re-reading this thread I've realized that this isn't your standard question about carrying drugs outside of their originally labelled containers. (That has been discussed in detail under "Carrying Medications to Scotland" or something similar.)
I take it you are concerned about confiscation at Customs because these drugs were purchased from a Foreign country. Am I correct? If so, you might want to check with Customs directly, well in advance of your travel. Or maybe you could get your prescription filled at home just this once to avoid any hassles. That might be the easiest thing to do.
I like the previous posters suggestion about taking extra medication with you incase of loss or extended travel. This is always a good plan. An extra week's supply is what my Doctor advised.