People who have overdosed on drugs will face a delay in receiving treatment after paramedics were told to take out-of-date drugs off their ambulances.
Staffordshire Ambulance Service said it had taken active charcoal and five other medicines off its vehicles following a review.
It said it was while paperwork was completed and the medicine would be back on ambulances by next week.
Patients needing the drug will meanwhile be given it at hospitals.
An ambulance spokesman said patient health would not be affected.
Other drugs have been removed from ambulances because they are either obsolete or, in the case of tetanus, should no longer be used for pre-hospital treatment under Department of Health guidelines.
They include treatments for asthma, vomiting and psychosis.
The spokesman said: "These drugs are not life-saving drugs - they are very useful drugs but not life-saving drugs.
"Some of the decisions to withdraw them have been taken because guidelines have changed and we're following best practice.
"The trust will be introducing seven additional drugs when staff have been trained to use them."