Pam MacCormack is going to wear this patch on her chest Sunday to honour Alex Zolpis during the MADD DASH raising money for Mothers Against Drunk Driving's Ottawa programs. (Ashley Wright/CBC)

Mother's Against Drunk Driving's fourth annual MADD DASH event in Ottawa will be extra special for one woman running in honour of drunk-driving victim Alex Zolpis and his father Ed, who she says changed her life.

Pam MacCormack is running and walking five kilometres in honour of Alex Zolpis, the 24-year-old who was killed Christmas Eve 2010 in an Ottawa parking garage.

Zolpis was accidentally killed by his friend Jack Tobin, who is now in prison for impaired driving causing death.

Alex Zolpis was the son of MacCormack's doctor, Ed Zolpis, who has been by her side helping her lose 150 pounds and begin a new life that involves better eating and regular exercise.

Taking part in the MADD DASH event — while wearing Alex Zolpis's name on her running jersey — is MacCormack's way to say thank you.

Alex Zolpis was killed in an Ottawa parking garage by his friend Jack Tobin, who was found to be drunk driving. (Facebook)

"When the race is over, I will give this to Dr. Zolpis," she said.

A second chance at life

MacCormack said when she asked Dr. Zolpis's permission to wear his son's name, he said it would be an honour.

"He's been absolutely amazing, helping me through a lot of the very difficult times," she said.

MacCormack says when she weighed more than 300 pounds, she had trouble walking, endured constant insults and had low self-esteem. Now she goes to the gym every day and is unafraid to try new things.

She says Dr. Zolpis gave her a second chance at life — something his son didn't get.

MacCormack says she has lost about 150 pounds thanks to Dr. Ed Zolpis and continues to work out daily. (Ashley Wright/CBC)

Hundreds of people are expected to take part in the event, which begins at 10 a.m. Sunday at Earl of March High School and goes through the Kanata Lakes neighbourhood.

The funds raised will go toward MADD Ottawa educational and support programs.

According to MADD Canada, Alex Zolpis is one of approximately 1,500 people killed in Canada each year by impaired drivers.