As many as 15 emergency ambulances were called to HMP Leeds every day when problems with prisoners taking former ‘legal highs’ reached their peak last year.
The prison’s Independent Monitoring Board said the continued availability and use of New Psychoactive Substances (NPS), such as Spice, had posed particular challenges during 2016.
Officers have frequently been required to transfer seriously affected and disturbed prisoners to segregation or out to hospital under escort.
Its annual report said: “The effects have not only been routinely disruptive and very damaging to the individual health and wellbeing of prisoners, but have also directly impacted the regime.
“Officers have frequently been required to transfer seriously affected and disturbed prisoners to segregation or out to hospital under escort.”
The report notes the problem became particularly serious between July and September last year, with up to 15 ambulances called out to medical emergencies related to the drugs.
So-called ‘legal highs’ were banned in May 2016 when new legislation made it an offence to supply the substances. Since then, Spice and other synthetic cannabinoids like it have been reclassified as Class B drugs.
The number of emergency calls linked to NPS was said to be putting further strain on health care systems internally and externally.
In some NPS related incidents, cells were also very badly damaged and need considerable repairs before being brought back into use.
A Prison Service spokeswoman said: “We are committed to transforming prisons into places of safety and reform and are taking unprecedented action to stop the supply and use of drugs and mobile phones in prisons.
“We remain vigilant to all incidents involving drones. A specialist squad comprising of prison and police officers continues to tackle the threat these devices pose to prison security and to bring to justice those who use drones to convey contraband in to our prisons.”