The number of drug-related crimes handled by China's courts is on the rise, with more criminals shifting to modern synthetic drugs, the Supreme People's Court revealed on Wednesday.

"New-type synthetic drugs, such as methamphetamine, or ice, and ketamine, are increasingly involved in drug criminal cases, and they have overtaken heroin as the primary drugs used in some parts of China," said Sun Jungong, spokesman of the Supreme People's Court.

In a new trend for drug-related crimes in recent years, medicines that contain ephedrine, such as cold medicines, have been illegally purchased in large amounts and utilized to manufacture drugs. Ephedra plants are also being used to extract ephedrine to produce ice, according to the Supreme People's Court.

The number of concluded cases involving the illegal harvest and sale of ephedra plants for drug use last year was 4.75 times as many as in 2009, and the amount of Ephedra plants involved last year was 10.28 times as high as in 2009, statistics from the Supreme People's Court show.

"Illegal use of synthetic drugs has become very serious in China in recent years," said Zhang Li, a researcher in narcotics control at the People's Public Security University of China. "It mostly targets young people and adolescents and does more harm to society than traditional drugs such as heroin."

One reason for the popularity of synthetic drugs, such as ice, is that they are usually produced as pills taken orally instead of by injection like heroin, which make them seem less threatening and attract young people, he said.

"Compared with heroin, synthetic drugs are less physically but more psychologically addictive, and they are also lethal taken in large doses.

"Recent research has proved such drugs can do great harm to the nervous system and cause mental illnesses such as schizophrenia."

Chinese courts accepted 32,606 drug-related criminal cases between January and May, 15.09 percent more than in the same period last year, according to Sun from the Supreme People's Court.

China's courts also concluded 76,280 drug-related criminal cases last year, an increase of 10.16 percent over the previous year, handing down verdicts to 81,025 criminals, he said.

Taking drugs harms users' health and easily leads to other crimes, said Gao Guijun, presiding judge at the Fifth Criminal Court of the Supreme People's Court.

In a case disclosed by the Supreme People's Court on Wednesday, 24-year-old Shi Chao killed two of his friends with a knife at their home in Guangdong province in 2011 over a trivial chore. Shi drank liquor and took ketamine that night before going to his friends' home.

He was executed in May, the Supreme People's Court said.

China deals with drug-related crimes harshly. Anyone found smuggling, selling, transporting or manufacturing more than 50 grams of heroin or ice is liable to penalties up to the death sentence.