Can Immunotherapy Cause Vomiting and How to Manage It

Vomiting can occur with immunotherapy, although it’s usually mild to moderate and less common than with many chemotherapies. ^[1] Combination immunotherapy (such as PD‑1 plus CTLA‑4) is more likely to cause nausea/vomiting than single‑agent therapy. [PM13] Some targeted antibody‑drug combinations used with immunotherapy (for example enfortumab vedotin plus pembrolizumab) also list nausea and vomiting among expected side effects. ^[2]

Why Vomiting Happens

• Immune‑related gut inflammation: Immunotherapy activates the immune system, which can mistakenly inflame the stomach or intestines (gastritis or colitis), leading to nausea, vomiting, abdominal pain, and diarrhea. [PM21] Immune‑related adverse events can start early, escalate quickly, and even appear after treatment stops, so ongoing vigilance is important. ^{[2] [3]}

• Treatment combinations: When two checkpoint inhibitors are combined, overall adverse events rise, and nausea/vomiting becomes more frequent compared to single‑agent therapy. [PM13]

• Individual drug profiles: Drugs like nivolumab include vomiting among reported adverse reactions in clinical trials. This supports that vomiting is a recognized side effect, even if rates are generally lower than with chemotherapy. ^[1]

When to Seek Medical Help

• Urgent signs: Persistent vomiting, inability to keep fluids down, severe abdominal pain, bloody or black stools, signs of dehydration (very dry mouth, dizziness), or tea‑colored urine warrant prompt contact with your care team. These can signal immune‑related colitis, gastritis, or liver involvement and need rapid evaluation. ^[4]

• Escalating symptoms: Because immune‑related side effects can progress quickly and even occur after stopping therapy, early reporting helps prevent complications. ^{[2] [3]}

Practical Coping Strategies

• Hydration first: Take small, frequent sips of fluids (water, oral rehydration solutions) to prevent dehydration; room‑temperature or ginger infusions may be gentler on the stomach. Ice chips or diluted electrolyte drinks can be more tolerable during active nausea. ^[5]

• Gentle foods: Try bland options (bananas, rice, applesauce, toast), lean proteins, and broths; avoid fatty, spicy, or very sweet foods that can worsen nausea. ^[5]

• Eating pattern tips: Eat small, frequent meals; avoid lying flat right after eating; ventilate rooms to reduce food odors. Some people find cold foods easier to tolerate than hot foods due to reduced smell. ^[5]

• Lifestyle tweaks: Wear loose clothing, practice slow deep breathing, and consider peppermint or ginger aromatherapy as adjuncts. ^{[6] [5]}

Medication Options

Antiemetic (anti‑nausea) medicines are tailored to symptom severity and your treatment plan.

• First‑line choices for mild to moderate symptoms:

  • 5‑HT3 receptor antagonists (e.g., ondansetron) are commonly used and can be considered even for lower emetogenic‑risk regimens. ^{[7] [8]}
  • Dopamine antagonists (e.g., metoclopramide or prochlorperazine). These help gastric emptying and reduce nausea. ^[9]

• Breakthrough or more troublesome nausea/vomiting:

  • Olanzapine can be added to improve control when standard regimens are not enough. ^{[10] [9]}
  • NK1 receptor antagonists (e.g., aprepitant) may be used in select cases. ^[9]

• Role of steroids: Dexamethasone is often part of antiemetic strategies; some guidance describes its use with checkpoint inhibitors, but your team will balance benefits with the risk of dampening immune activity. Steroid decisions are individualized and should be directed by your oncology team. ^[11]

Special Considerations in Immunotherapy

• Assess for immune‑related causes: If vomiting is accompanied by diarrhea, blood in stool, severe cramps, or persistent abdominal tenderness, clinicians may evaluate for colitis or gastritis and may treat with corticosteroids or other immunosuppressive measures when indicated. Early recognition improves outcomes and reduces the chance of treatment interruption. ^[2] [PM21]

• Combination regimens: If you’re receiving dual checkpoint inhibitors, be aware that the overall risk of adverse events, including nausea/vomiting, is higher; proactive symptom reporting helps tailor supportive care. [PM13]

Emetogenic Risk Context

While traditional chemotherapy is categorized by emetogenic risk, many immunotherapies fall into minimal to low emetogenic risk; however, individuals vary, and combinations or specific agents can shift risk. Preventive antiemetic strategies are adapted based on the expected risk and your prior symptom history. ^{[12] [7]}

Action Plan You Can Use

• Track symptoms: Keep a simple diary of when nausea/vomiting occurs, triggers, and what helps; share this with your care team for precise adjustments. ^[5]

• Have medicines on hand: Ask for a rescue antiemetic to use at the first sign of nausea and clarify dosing and timing; this often prevents escalation. If one agent doesn’t work, your team can switch or add another based on guidelines. ^{[9] [8]}

• Know red flags: Sudden worsening, severe pain, blood in stool, or signs of dehydration require same‑day contact. Prompt evaluation is key because immune‑related gut issues can intensify quickly. ^{[2] [4]}

Summary

• Yes, immunotherapy can cause vomiting, typically at lower rates than many chemotherapies, but risk increases with combination regimens and certain agents. ^[1] [PM13] ^[2]
• Management blends practical measures and antiemetic medications, with close monitoring for immune‑related gut inflammation that may need specific treatment. ^{[4] [9]}
• Early reporting and individualized support help maintain treatment while protecting safety and comfort. ^{[2] [3]}