I started taking Plavix once a day and I also take Prevacid (lansoprazole) and on occasion Prilosec. Is there any interactions with these drugs?

Absolutely. There is a well know interaction between plavix and proton pump inhibitors. Plavix is a prodrug(inactive) and is activated in the liver. This process of activation is blocked by proton oump inhibitors. Specifically with nexium and prilosec, also somewhat with other ppis. The only one safe to use is dexilant (dexlansoprazole) and possibly protonix. Or change plavix to effient or brilinta under guidance of MD.