The socialite was responding to speculation that she had revisited her past experience of drug-using, after being photographed bleary-eyed with blood on her arm on a night out last month.
"When I saw those pictures, I knew what everyone would be thinking and it broke my heart," Palmer-Tomkinson told the new issue ofCloser magazine, on sale now. "Yes, it looked like I was on drugs, but I've been clean for years.
"After I went to rehab, I signed a statement agreeing to do a random blood test every year and I never failed one once. That doesn't stop me enjoying the odd glass of wine though!"
The 39-year-old continued: "I really want to prove to people that I'm not just some party girl - I want to achieve something. I've realised that having money doesn't make you happy. It's about having a healthy mind and soul.
"Fame doesn't mean anything. I've ditched all the old hangers-on who were a bad influence on me and now I surround myself with people who don't see drugs as a priority. If anyone takes drugs in front of me, I'm never tempted to join in."
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