What pain management options are available for a patient with rectal and mouth pain, including canker sores, and a history of colorectal cancer?

From the Guidelines

Pain management for this patient should prioritize a multimodal approach, incorporating both pharmacologic and nonpharmacologic interventions, as recommended by the NCCN Adult Cancer Pain Guidelines Panel 1. Given the patient's history of colorectal cancer, current rectal bleeding, and new onset of chest pain, along with mouth pain due to canker sores, a comprehensive pain assessment is crucial.

Topical Options

For mouth pain and canker sores, consider:

• Benzocaine gels (such as Orajel or Anbesol)
• Lidocaine viscous solution (2%)
• Magic mouthwash (typically containing lidocaine, diphenhydramine, and an antacid) These can be applied directly to painful areas 3-4 times daily. Salt water rinses (1/2 teaspoon salt in 8 ounces warm water) can also provide relief.

Systemic Options

Systemically, acetaminophen (500-1000mg every 6 hours, not exceeding 4000mg daily) is generally safe. NSAIDs like ibuprofen (400-600mg every 6-8 hours) can help but should be used cautiously due to potential gastrointestinal irritation.

Rectal Pain Management

For rectal pain, consider:

• Sitz baths (warm water soaks) 2-3 times daily
• Witch hazel pads
• Lidocaine ointment (2-5%) It's essential to address underlying causes - dental evaluation for persistent mouth sores and gastroenterology follow-up for rectal pain are crucial.

Consultation

For more severe pain, consultation with an oncologist is recommended as they may prescribe appropriate opioids while considering the patient's cancer history, as suggested by guidelines on managing chronic pain in survivors of adult cancers 1. The patient's quality of life and ability to cope with pain should be regularly assessed, emphasizing good communication between the patient and their medical providers 1.

From the FDA Drug Label

PURPOSE Pain reliever/fever reducer PRINCIPAL DISPLAY PANEL - 77 g Bottle Carton TopCare® health COMPARE TO ICY HOT® ACTIVE INGREDIENTS* MAXIMUM STRENGTH LIDOCAINE Cold & Hot Pain Relieving Lidocaine Cream 4% Lidocaine • 1% Menthol LIDOCAINE 4% / TOPICAL ANALGESIC MENTHOL 1% / TOPICAL ANALGESIC Helps to Numb Away Pain Non-Greasy Maximum Strength External Analgesic with 4% Lidocaine

For pain management, acetaminophen (PO) 2 can be considered for the patient's rectal and mouth pain. Additionally, lidocaine (TOP) 3 may be used to help numb away pain, particularly for the mouth pain due to canker sores.

• Pain relief: acetaminophen (PO) can be used as a pain reliever.
• Topical analgesic: lidocaine (TOP) can be used as a topical analgesic to help numb away pain. Regarding the magic mouthwash for canker sores, there is no direct information in the provided drug labels.

From the Research

Pain Management Options

• For a patient with rectal and mouth pain, including canker sores, and a history of colorectal cancer, acetaminophen (paracetamol) can be considered as a first-line analgesic for mild to moderate acute pain 4.
• Acetaminophen is effective against a variety of pain types and has a lower risk of gastrointestinal bleeding and organ adverse effects compared to nonsteroidal anti-inflammatory drugs (NSAIDs) 5, 6.
• Intravenous acetaminophen has been shown to be effective in reducing pain after abdominal laparoscopic surgery, with significant reductions in pain intensity and improved patient global evaluations 7.

Management of Canker Sores

• Magic mouthwash may be considered for the management of canker sores, although there is limited evidence to support its use in this context.
• Topical anesthetics, such as lidocaine, may also be considered for the management of mouth pain associated with canker sores.

Considerations for Patients with Colorectal Cancer

• Patients with a history of colorectal cancer may be at increased risk of toxicity from certain medications, including NSAIDs and opioids 8.
• Acetaminophen may be a suitable alternative for these patients, although dosing should be individualized and monitored closely to minimize the risk of hepatotoxicity 4.
• Patients with short course radiation may present with acute symptoms 1-2 weeks after completion of radiation, and treatments such as Bentyl (dicycloverine) and steroids may be helpful in managing these symptoms 8.