Over 4,000 packs of co-codamol 30/500 effervescent tablets made by the manufacturer Zentiva Pharma UK Limited have been recalled due to safety concerns.

People who take the drug — which is widely used for pain relief — have been asked to check batch numbers on medication boxes to ensure they do not have one of the 4,464 packs which have been recalled.

Batch Number 1K10121 has been found to potentially have too little of the active ingredients (codeine phosphate and paracetamol), which may mean that the medicine does not work as it should do.

Other tablets from the same batch may contain too much of the active ingredients and could potentially result in overdose, the Medicines and Healthcare products Regulatory Agency (MHRA) said in an update today (16 June).

Patients who have the packs with these batch details have been urged to return them to their pharmacy for a replacement.

Healthcare professionals have been advised to stop supplying the affected batch immediately, quarantine all remaining stock and return them to their supplier or the marketing authorisation holder Zentiva Pharma UK Ltd.

Symptoms of paracetamol overdosage in the first 24 hours are pallor, nausea, vomiting, anorexia and abdominal pain, the MHRA warned.