Thank you for posting your query at DoctorSpring.com. I have noted your husband's symptoms and diagnosis.
Oxycodone should be used once in 12 hours, as the safety of doses taken more than twice a day is not known. However, the strength of each dose may be increased to 10 mg or higher, depending on the response.
Other medications such as pregabalin or gabapentin may also be used to get pain relief.
I hope it helps. please feel free to follow-up. Best wishes,
Dr. Sudhir Kumar MD (Medicine), DM (Neurology)
Senior Consultant Neurologist