India's Central Drugs Standard Control Organisation ordered pharmaceutical manufacturers on Tuesday to add mandatory warning labels barring the use of chlorpheniramine-phenylephrine cough and cold combinations in children under four years old.

The Drugs Technical Advisory Board reviewed evidence on the fixed-dose combinations, which are widely marketed as paediatric syrups for common colds. The board concluded that the ingredients offered little proven benefit for very young children while carrying risks of adverse effects, according to the notification issued by the drug regulator.

Manufacturers must now print the restriction prominently on product packaging and promotional material. The order affects a large segment of India's over-the-counter cough syrup market, where such combinations have long been sold without prescription and frequently administered to infants and toddlers.

The move follows years of scrutiny of Indian-made cough syrups after contaminated products were linked to child deaths abroad. The Drugs Controller General of India has faced pressure from the World Health Organization and domestic paediatric associations to tighten oversight of formulations given to children.

Paediatricians welcomed the restriction but urged wider public awareness. The Indian Academy of Pediatrics said clearer labelling would help protect the youngest patients. "Parents often reach for these syrups without knowing they can harm small children," a spokesperson said.