A physician assistant who was one of New Hampshire’s biggest over-prescribers of opioids can no longer practice medicine in the state.

The New Hampshire Board of Medicine announced Wednesday that it is revoking Chris Clough’s license after he failed to comply with restrictions placed on it.

The board had previously investigated and sanctioned Clough for over-prescribing opioids including oxycodone, methadone and other drugs to relieve his patients’ pain.

Clough failed to have a supervising physician pre-approve all of his patient procedures before he conducted them, as stipulated by the Board of Medicine.

He is an employee of N.H.-based pain management company Pain Care.

An NHPR investigation last year found Clough took $210,000 in Medicare reimbursement in 2012 alone – more than any other physician’s assistant in New Hampshire.

Of the 325,000 painkillers Clough prescribed from 2010 to 2013, half were given to just 22 of his patients.

Clough hired a lawyer to contest the board’s allegations of misconduct a few years ago, testifying that he saw patients who had undergone multiple surgeries and were suffering crippling pain that could only be relieved by prescription opioids.