Police are urging the public to exercise caution after a plastic carrier bag containing prescription drugs was stolen in Moreton.
Officers say the medication could be dangerous if taken by someone it is not prescribed for.
The robbery took place around 12.30pm on Tuesday when a man riding a bike snatched the Tesco's bag from a pedestrian before riding away.
Although uninjured, the victim has been left shaken following the incident in Blundells Drive.
The medication, a mixture of painkillers and anti-depressants, is: 60 x 25mg Zomorph tablets; 112 x 150mg Pregabilin tablets and 28 x 25mg Amitriptyline tablets.
An investigation is ongoing.
Anyone finding the drugs should call Merseyside Police on 101 or hand it in to the nearest police station or pharmacy.