Question: Whatever happened in the case of a man whose body was found in Koko Crater Botanical Garden late last year?

Answer: The Department of the Medical Examiner identified the man’s body as that of 48-year-old Ralf Kellen of Veltheim, Aargau, Switzerland.

The department found the cause of death was the combined toxic effects of codeine and methadone, and ruled it as accidental.

The Honolulu Fire Department began searching the afternoon of Nov. 3 for a possible missing person. A security guard reported to police that the person’s unoccupied car was parked for more than 24 hours at the city park, at the end of Kokonani Street, and reported it to police, which prompted the search.

A fire helicopter conducted a search until nightfall Nov. 3, and resumed the search at 6 a.m. Nov. 4 in the lower crater area.

Fire rescue personnel aboard Air 1, the fire helicopter, spotted Kellen’s body about 7 a.m. Nov. 4 in the crater.

The body was recovered 50 feet off the botanical garden service trail, Honolulu Fire Department Capt. Carlton Yamada said.

Police initially classified the case as an unattended death because preliminary findings did not indicate any suspicious circumstances.

In an interview Wednesday, Abby Collier, a pharmacology professor at the University of Hawaii’s John A. Burns School of Medicine, explained what happens when methadone and codeine combine.

“The action of them combined is stronger than the action of them alone,” Collier said.

“It goes into the part of the brain that regulates breathing, it stops working and you actually stop breathing,” she said. “People don’t know. People get drowsy, and they go to sleep.”

Collier cautions against receiving prescriptions from different doctors and dispensed from different pharmacies because no one pharmacist or doctor is overseeing whether there might be any harmful drug interactions.

Methadone is almost exclusively prescribed to help individuals end their addiction to opiate drugs used as painkillers, such as morphine and oxycodone, she said. The painkillers are often used by those with long-term severe pain, cancer patients and trauma patients. If they become tolerant of or have a physical reaction to such drugs, their physician may switch them to methadone.

Codeine, which is a controlled substance in some countries such as the United States and Switzerland, is an over-the-counter drug in other countries, such as the United Kingdom. It is a mild painkiller, but is also used in cough syrups as a cough suppressant.