Matthews recalled fighting off an "unnerving" older man when he lived on the Caribbean island of Saint Bart's at the age of 18, commenting that he "felt like a fly trapped in a spider's web".
"I never thought Le Feeling nightclub was inappropriately named until this particular evening," he wrote in his book Confessions of a Chelsea Boy, as serialised in Now.
"As my vodka went down, I started to feel unusually light-headed. I saw that the man's cold gaze had turned into a suggestive smile. It was then I suspected he might have spiked my drink."
After leaving the club and feeling his body go numb, Matthews remembered how the man "approached and, knowing I was unable to move or speak, pretended to look after me".
He continued: "When there was no-one around he'd run his fingers through my hair and whisper to me that everything was going to be okay. I felt like a fly trapped in a spider's web.
"What did this man want with me? More than anything it was likely to be a sexual nature, but what if I woke up in a bathtub without a kidney? What if I didn't wake up at all?
"The next thing I remember is being dragged into his car. Sensing this would be my only chance to get out of this vile person's clasp, I began making as much noise as possible, hoping desperately that someone would notice.
"He tried to cover my mouth with his hand, but... thankfully the struggle attracted one passer-by's attention, who alerted my good friend Hervé."
Matthews also spoke about taking acid with Made in Chelsea co-star Oliver Proudlock, an experience he described as like "Fear and Loathing in the West Country", and an altercation with Colonel Gaddafi's son in extracts from Confessions of a Chelsea Boy.
The book is released on September 26.