(Newser) – Six years before she died of a heroin overdose, Peaches Geldof apparently swore drugs wouldn't kill her. She's said to have made the vow in her own blood—using a syringe—in the diary of rocker Pete Doherty, himself well known for drug use, the New York Daily News reports. "I solemnly swear I am not going to die," she allegedly wrote, years after her mother, Paula Yates, died from a drug overdose. A page from Doherty's recently published diary shows her name and phone number in what appears to be blood. Publishers can't confirm, however, whether Geldof or Doherty wrote the information, the Daily Mail reports; Doherty has previously shown artwork made using his blood.