Lawyers for the patient claim that long-term treatment with temozolomide risks secondary cancer, chronic liver problems and reinforces the fear of death.
The patient, who was originally treated for a cancerous brain tumour, said he had suffered fatigue, joint pain, gastrointestinal distress, recurrent mouth ulcers and nausea, because of the ongoing treatment.
His prolonged chemotherapy programme was only discovered when the consultant treating him, Prof Ian Brown, retired.
A consultant who took over his care then confirmed the four-week cycles of chemotherapy he was undertaking were not needed.