Over a decade since "moving away from that life" she is a board member of the Drug Heath and Development Project (DHDP), overseeing needle exchanges in the lower North Island.
Fortunately Ms Kerrisk never overdosed, but she knew of many others who had, and her past experiences had given her a "unique understanding" into how hard it could be for a drug user to seek help.
Although naloxone was a prescription medication, chances of a drug user approaching a medical professional for it was slim, she said.
"Amongst the community that I mix with, the option of going to get it from your GP is like the mystical unicorn.
"To justify the GP giving it to you you'd have to tell them you're using opiate drugs and you're at risk of an overdose and then they would probably freak out at you."
She said due to the way drug users were usually perceived, they may be reluctant to call an ambulance in the event of an overdose, so "slapping, pulling out nose hairs or putting the victim in a cold shower" were common ways an overdose was treated.
Ms Kerrisk said one dose of naloxone would cost about five dollars and some agencies, including NZ Drug Foundation and Needle Exchange Service Trust were doing research, collaboration and consultation, "looking into the [case] and examining its merits".
Overseas institutes that had run naloxone distribution programs had seen "really successful" results, with the institutes keeping count of overdoses reversed with the drug using a reporting system.
Naloxone could not be converted to give any kind of high and if a suspected overdose was incorrect then the drug would have no effect on someone without opiates in their system, she said.
Ms Kerrisk said there were around 37 recorded deaths due to overdose in New Zealand each year and introducing the drug into needle exchanges, where drug users had established relationships, would be the most effective way to get the drug out to people who could benefit from it most.
She said naloxone needed to be "taken down a peg" from being a prescription drug to one that could be handed out through a verbal conversation with a pharmacist.
Now living in Lower Hutt with her family, Ms Kerrisk advises those using opiate drugs and finding they have no control over how much they're using to take a look at themselves.
"If your life's a mess and in tatters, do you keep riding on and hope for a different result or change?"