ABUJA, Dec. 19 (Xinhua) -- The Nigerian government on Wednesday said at least 2.5 million bottles of codeine-based cough syrup have been recalled from circulation nationwide, following a ban earlier in the year.

In a statement, Health Minister Isaac Adewole said the ban on the production, distribution, and sale of codeine-based cough syrup had helped in curbing the menace of drug abuse, likewise helping those enslaved by hard drugs to build new lives.

"Since we banned codeine syrup in the country, till today, over 2.5 million bottles have been recalled, and we will not relent in ensuring that this menace is curbed to the barest minimum," Adewole said in the statement issued in Abuja.

Codeine is a narcotic pain-reliever and cough suppressant similar to morphine and hydrocodone.

The ban on all codeine-based cough syrup has taken effect in Nigeria since May 1, amid increased reports of the abuse of such substances in Africa's most populous country.

Health experts had been calling for the ban of codeine in Nigeria as the abuse of the substance became incessant.

Apart from codeine, other substances commonly abused in Nigeria include cannabis, tramadol and other opioids, benzodiazepines, cocaine and heroin.

The official described the escalation of drug abuse in Nigeria as "worrisome," saying even some bizarre substances are now being abused.

Adewole said cough syrups containing codeine had since been replaced with dextromethorphan which is less addictive.

The dextromethorphan is a cough suppressant used to treat coughing, and also a drug of the morphinan class with sedative, dissociative, and stimulant properties.