UNC professor: It's 'plausible' too much cold medicine caused Raleigh man to kill his wife

RALEIGH (WTVD) -- When a professor at the UNC School of Pharmacy heard the story of a Raleigh man accused of murdering his wife, her ears immediately perked up.

That's because in a 911 call the man said, "I took Coricidin, Cough and Cold Coricidin HBP because I know it can make you feel better. A lot of times I can't sleep at night, so I took some."

Listen to the chilling moment Matthew Phelps calls 911:

"As a pharmacist, it was one of the first things that caught my attention when I saw there was a medication that could have potentially been overdosed," Dr. Stefanie Ferreri told ABC11. "And the side effects that the person was talking about are typical side effects of the medication that he was taking."

The caller said he had taken Coricidin Cough and Cold HBP, and Dr. Ferreri said the active ingredient in that drug that causes the symptoms the caller described is called Dextromethorphan.

She said it can be found in more than 100 over-the-counter medications.

Police have charged 28-year old Matthew Phelps with the murder of his 29-year-old wife Lauren.

He told the 911 dispatcher, "I had a dream and then I turned on the lights and she's dead on the floor."

He went on to say, "I have blood all over me and there's a bloody knife on the bed, and I think I did it."

Stay on top of breaking news stories with the ABC11 News App

"Dextromethorphan, which is a cough suppressant, typically helps people sleep at night when they have a common cold, when they are coughing," said Ferreri. "And typically that is the medication that has been notorious for causing hallucinations or euphoria or agitation if taken in too high of doses."

And while she said she's never heard of the level of violence involved in the Raleigh murder, she thinks the husband's claim is at least plausible.

"It depends on what other things were in the patient's system or what other things could be interacting with the medication. But it could be a possibility, yes."

The pharmacy professor said she plans to closely watch this case and even use it as a teaching tool, saying it's an opportunity to raise awareness of Dextromethorphan abuse.

"Dextromethorphan is a medication that has been known to cause abuse. It's one of the over-the-counter medicines that unfortunately, one in 30 teenagers use to get that feeling of high."

She said those interested should visit the website stopmedicineabuse.com and read up on the subject.