How to manage a patient with opioid use disorder (OUD) due to active heroin use who requires chemotherapy for cancer treatment?

Managing Active Heroin Use in a Patient Requiring Chemotherapy

Do not delay or deny chemotherapy while simultaneously initiating medication-assisted treatment (MAT) with buprenorphine or methadone for the opioid use disorder—both conditions require urgent, concurrent treatment. 1, 2

Immediate Dual-Priority Approach

1. Initiate Medication-Assisted Treatment for Opioid Use Disorder

Start buprenorphine/naloxone (Suboxone) or arrange methadone treatment immediately, as MAT reduces mortality, prevents relapse to more dangerous opioid use, and does not interfere with chemotherapy administration. 1, 3, 4

• Buprenorphine/naloxone is preferred for office-based treatment and can be initiated in primary care or oncology settings after confirming withdrawal symptoms using the Clinical Opiate Withdrawal Scale (COWS score >8). 1
• Start with 4-8 mg sublingual buprenorphine based on withdrawal severity, targeting a maintenance dose of 16 mg/day for most patients. 1
• Methadone remains the gold standard with the strongest evidence for reducing heroin use, mortality, criminal activity, and HIV transmission, but requires administration through federally certified Opioid Treatment Programs. 1, 3, 4

Critical pitfall to avoid: Never withhold or delay MAT due to concerns about drug interactions with chemotherapy—these medications are safe to use together, and denying treatment poses greater risk of morbidity and mortality from untreated opioid use disorder. 2, 5

2. Proceed with Chemotherapy Without Delay

Continue the planned chemotherapy regimen on schedule, as active substance use is not a contraindication to cancer treatment. 6

• The presence of opioid use disorder does not preclude effective cancer treatment and should not delay potentially life-saving therapy. 6
• Coordinate care between oncology and addiction medicine to ensure both conditions are managed simultaneously. 2

Managing Cancer Pain in Patients on MAT

Continue the patient's usual MAT dose (buprenorphine or methadone) and add separate opioid analgesics for cancer pain management. 1, 2

Pain Management Strategy:

• Maintain the baseline MAT dose unchanged—this treats the opioid use disorder, not cancer pain. 1
• Add full opioid agonists (morphine, hydromorphone, fentanyl) at higher doses and shorter intervals than typical due to cross-tolerance from chronic opioid exposure. 1
• Use scheduled dosing rather than as-needed to prevent pain recurrence and patient anxiety. 1
• Avoid mixed agonist-antagonist opioids (nalbuphine, pentazocine, butorphanol) as these will precipitate withdrawal in opioid-tolerant patients. 6

For patients on buprenorphine specifically: The partial agonist properties create a "ceiling effect" that may complicate acute pain management. Consider either:

• Continuing buprenorphine and adding high-dose full agonists (requires significantly higher opioid doses). 1
• Temporarily transitioning to methadone or full agonist opioids for the duration of intensive cancer treatment, then returning to buprenorphine. 1

Addressing Concomitant Substance Use

Screen for and manage concurrent benzodiazepine or other CNS depressant use, as this combination with opioids dramatically increases overdose risk. 6, 5

• Do not categorically deny MAT to patients using benzodiazepines—prohibiting treatment poses greater risk than the opioid use disorder itself. 5
• Educate patients about risks of combining benzodiazepines, alcohol, or other sedatives with opioids. 5
• If concomitant benzodiazepine use is present, gradually taper the benzodiazepine (not the MAT) or reduce to the lowest effective dose. 2
• If patient is sedated at time of dosing, delay or omit the buprenorphine dose until alert. 5

Essential Supportive Measures

Harm Reduction:

• Provide naloxone for overdose reversal to the patient and family members with education on administration. 1, 2
• Refer to syringe service programs to reduce HIV and hepatitis C transmission risk. 1
• Screen for HIV, hepatitis C, and other infectious complications of injection drug use. 1

Behavioral Therapy Integration:

• Combine MAT with cognitive-behavioral therapy, contingency management, or motivational enhancement therapy to reduce opioid misuse and improve treatment retention. 1, 2
• Brief counseling using motivational interviewing decreases quantity and frequency of drug use. 1

Monitoring:

• Initial weekly follow-up, then monthly once stable on MAT. 1
• Use urine drug testing to support diagnosis and monitor treatment, testing for both prescribed and illicit substances including benzodiazepines. 1, 5
• Review state prescription drug monitoring program (PDMP) data to identify other controlled substances. 2

Managing Chemotherapy-Related Side Effects

Anticipate and aggressively treat opioid-induced adverse effects, which may be exacerbated in patients on MAT:

Constipation:

• Always begin prophylactic bowel regimen when starting or escalating opioids: senna with or without docusate daily, titrated to achieve soft, formed bowel movements every 1-2 days. 6
• If constipation develops despite prophylaxis, add magnesium-based products and bisacodyl. 6
• Consider peripherally acting mu-opioid receptor antagonists (PAMORAs: methylnaltrexone, naldemedine, naloxegol) if primary cause is opioid-related, though insurance access may be limited. 6

Nausea and Vomiting:

• Rule out constipation and other causes first. 6
• Metoclopramide is first-line for chronic nausea including opioid-related, with both central and peripheral effects. 6
• For patients with prior opioid-induced nausea, use prophylactic antiemetics (metoclopramide or prochlorperazine) around the clock for first few days. 6
• If nausea persists beyond one week, reassess cause and consider opioid rotation. 6

Critical Pitfalls to Avoid

• Never abruptly discontinue MAT—this constitutes patient abandonment, increases overdose risk due to loss of tolerance, and dramatically increases relapse risk. 6, 2
• Never delay chemotherapy while "getting the addiction under control"—both conditions require simultaneous urgent treatment. 1, 2
• Never use the MAT dose to treat cancer pain—these are separate clinical needs requiring separate opioid dosing strategies. 1
• Never initiate naltrexone without ensuring 7-10 days opioid-free to prevent precipitated withdrawal syndrome. 2
• Never withhold MAT due to stigma or misconceptions about "replacing one drug with another"—MAT is evidence-based, life-saving treatment. 2

Long-Term Management

Maintain MAT indefinitely rather than attempting time-limited detoxification, as discontinuation of pharmacotherapy dramatically increases relapse risk. 1, 3

• Long-term treatment (maintenance) is associated with better outcomes and allows restoration of social connections. 1, 4
• Reassess regularly for relapse risk, which is highest in early recovery. 1
• Maintain a nonjudgmental, blame-free environment to encourage continued engagement in both addiction and cancer care. 1