Chinese authorities have tightened management of a cough suppressant called dextromethorphan and several other psychotropic drugs to prevent illegal sales and use of them, according to a notice released by the National Medical Products Administration and National Health Commission on Tuesday.

The notice was published following a circular released earlier this month that included dextromethorphan, a medication tied to overdoses among teenagers for years, into its national catalog of Category II Psychotropic Drugs, and adjusted categories of several other similar controversial drugs.

The notice said that from July 1, manufacturers that do not obtain designated production qualifications for these drugs from local drug regulators are barred from producing them. They are also barred from outsourcing production.

Drugmakers are also required to change drug labels and instructions to align with the shifts in these medicines' categories.

Meanwhile, drug distribution companies without corresponding qualifications are barred from making new purchases and their existing inventories should be sold off or returned in accordance with regulations.

Medical institutions are also required to step up management of these medicines, it added.