Opioid Therapy vs Multimodal Analgesia in Head and Neck Cancer

The purpose of this study is to compare the daily pain level scores for patients taking opioids alone for pain relief, compared with those treated by multimodal analgesia with three medications: pregabalin, naproxen, and acetaminophen, with the ability to switch over to opioid medications if needed. In addition to pain level scores, this study will compare opioid use (length of time and doses taken), quality of life, admissions to hospital, feeding tube requirements, weight loss, and treatment interruptions between these two analgesic regimens.

A significant proportion of patients undergoing radiotherapy alone or chemotherapy and radiotherapy together for their head and neck cancer experience mucositis, which is severe pain in the mouth and throat caused by radiation treatment. Patients often enter a cycle of pain, difficulty swallowing, malnourishment, and reduced quality of life. This may translate into decreased oral intake requiring a feeding tube, and radiation or chemotherapy treatment breaks, which reduce the chance of tumour control and cure.

Currently, opioid therapy is the cornerstone of head and neck cancer pain management. Although effective for pain relief, opioids can have side effects.

As an alternative to opioid treatments, "multimodal analgesia" is a treatment using medications from different classes with different mechanisms of action. Examples of analgesic medications used for multimodal analgesia include medications similar to acetaminophen or ibuprofen, and others.

The primary purpose of this study is to compare pain level scores of patients taking opioids versus patients taking multimodal analgesia.

Eligibility Criteria:
Inclusion Criteria:

* Age 18 or older
* Willing to provide consent
* Histologically confirmed mucosal head and neck malignancy
* Undergoing chemoradiotherapy or radiotherapy alone with a planned total radiation dose of 50 Gray (Gy) or greater
* Eastern Co-operative Oncology Group (ECOG) performance status 0-2
* Life expectancy \> 6 months
* Onset of 4/10 pain on the 11-Numeric Rating Scale that is localized to the mucosa of the mouth or throat, before or during radiation treatment, that is not caused by a current oral candidiasis infection.
* Ability to take pills, either by mouth or crushed via NasoGastric (NG) tube or Gastrostomy tube (G-tube)
* Ability to complete the study questionnaires and pain diary
* Ability to sign consent without requirement for a substitute decision maker

Exclusion Criteria:

* Skin and salivary gland malignancies
* High daily opioid use at time of enrollment (defined as 30 mg oral morphine equivalent dose or higher)
* Concurrent second active malignancy
* Pregnant or lactating women
* Psychological disorder requiring pharmacologic treatment
* Regular systemic steroid use
* Regular anticonvulsant or antidepressant use
* Renal Impairment (defined as creatinine clearance \< 60 mL/min)
* Liver Dysfunction (defined as total bilirubin \> 34.2 µmol/L)
* Documented true allergy to acetaminophen, NSAIDs, pregabalin or opioids
* History of upper gastrointestinal bleed
* Known bleeding disorder
* History of or current substance use disorder