Police are warning people not to consume medication which has been lost by two patients in Chesterfield.
People are also being urged to hand the prescriptions in to a pharmacy or police station if they find them.
A prescription picked up from Peak Pharmacy, on Knifesmithgate in Chesterfield, was lost on Thursday August 1.
The white packet has the words NHS Tims and Parker Peak Pharmacy written on it and contains medication including cimetidine, lamotrigine and risperidone.
Police say some of those drugs can have damaging effects if taken outside of the prescription, with overdose symptoms including fainting and seizures.
A separate batch of prescription medication was left in a carrier bag outside the Portland Hotel, in Beetwell Street, Chesterfield, also on Thursday.
The prescription includes packets of lithium, sertraline, olanzapine, solufen and temazepam.
Temazepam in particular can be dangerous if taken in large quantities and with alcohol, and can result in severe drowsiness, confusion, muscle weakness and coma in extreme cases.
The prescription was left in one of two carrier bags, the second of which contained birthday cards and a teddy bear.
Inspector Russ Dakin, from the community safety unit in Chesterfield, said: “The medication that has been lost is vital to the wellbeing of the patients and we are extremely keen to recover them.
“They are issued with strict instructions from medical experts and should not be consumed by anyone other than the person named on the prescription.
“I would urge anyone who finds the medication to hand it in immediately at a pharmacy, hospital or at their nearest police station.”
People should call Derbyshire police on 101 if they find the medication.