Pembrolizumab side effects

What does the patient leaflet say about side effects?

From the patient leaflet: What are the possible side effects of KEYTRUDA?

KEYTRUDA can cause serious side effects. See “What is the most important information I should know about KEYTRUDA?” Common side effects of KEYTRUDA when used alone include: feeling tired, pain, including pain in muscles, rash, diarrhea, fever, cough, decreased appetite, itching, shortness of breath, constipation, bones or joints and stomach-area (abdominal) pain, nausea, and low levels of thyroid hormone. Side effects of KEYTRUDA when used alone that are more common in children than in adults include: fever, vomiting, headache, stomach area (abdominal) pain, and low levels of white blood cells. […]

What does the label list?

From the label: adverse reactions

Most common adverse reactions (reported in ≥20% of patients) were: KEYTRUDA as a single agent: fatigue, musculoskeletal pain, rash, diarrhea, pyrexia, cough, decreased appetite, pruritus, dyspnea, constipation, pain, abdominal pain, nausea, and hypothyroidism.

Table 8: Selected Adverse reactions occurring at same or higher incidence than in placebo arm Adverse Reactions Occurring in ≥10% of Patients Receiving KEYTRUDA in KEYNOTE-054

Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.

From the label: adverse reactions, continued

The following clinically significant adverse reactions are described elsewhere in the labeling. Severe and fatal immune-mediated adverse reactions [see Warnings and Precautions (5.1) ]. Infusion-related reactions [see Warnings and Precautions (5.2) ]. Most common adverse reactions (reported in ≥20% of patients) were: KEYTRUDA as a single agent: fatigue, musculoskeletal pain, rash, diarrhea, pyrexia, cough, decreased appetite, pruritus, dyspnea, constipation, pain, abdominal pain, nausea, and hypothyroidism. ( 6.1 ) KEYTRUDA in combination with chemotherapy or chemoradiotherapy: fatigue/asthenia, nausea, constipation, diarrhea, decreased appetite, rash, vomiting, cough, dyspnea, pyrexia, alopecia, peripheral neuropathy, mucosal inflammation, stomatitis, headache, weight loss, abdominal pain, arthralgia, myalgia, insomnia, palmar-plantar erythrodysesthesia, urinary tract infection, hypothyroidism, radiation skin injury, dysphagia, dry mouth, and musculoskeletal pain. ( 6.1 ) KEYTRUDA in combination with chemotherapy and bevacizumab: peripheral neuropathy, alopecia, anemia, fatigue/asthenia, nausea, neutropenia, diarrhea, hypertension, thrombocytopenia, constipation, arthralgia, vomiting, urinary tract infection, rash, leukopenia, hypothyroidism, decreased appetite, pyrexia, epistaxis, decreased white blood cell count, and stomatitis.

What do FAERS reports show?

104,596 reports list pembrolizumab among the medicines taken, each a report of something that happened, not proof the medicine caused it; 18,742 are coded as a death and 43,925 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 20 reactions below, 16 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.

Reports received each year

• 2,323
• 4,119
• 4,867
• 6,374
• 6,810
• 8,400
• 12,624
• 15,879
• 16,086
• 17,364
• 7,871

• 2016
• 2017
• 2018
• 2019
• 2020
• 2021
• 2022
• 2023
• 2024
• 2025
• 2026

The 25 most reported reactions

• Malignant Neoplasm Progression12,012
• Death (an outcome recorded in the report)5,848
• Diarrhoea (named in the label)5,719
• Fatigue (named in the label)5,112
• Off Label Use (a use or a product term, not a reaction)4,755
• Pyrexia (named in the label)3,870
• Rash (named in the label)3,717
• Nausea (named in the label)3,563
• Product Use In Unapproved Indication (a use or a product term, not a reaction)3,541
• Decreased Appetite (named in the label)3,305
• Hypertension (named in the label)3,231
• Hypothyroidism (named in the label)2,917
• Asthenia (named in the label)2,774
• Drug Ineffective (a use or a product term, not a reaction)2,575
• Product Use Issue (a use or a product term, not a reaction)2,565
• Interstitial Lung Disease2,532
• Acute Kidney Injury (named in the label)2,447
• Anaemia (named in the label)2,417
• Malaise2,383
• Dyspnoea (named in the label)2,351
• Neutropenia (named in the label)2,336
• Pneumonia (named in the label)2,223
• Pneumonitis (named in the label)2,221
• Vomiting (named in the label)2,206
• Neuropathy Peripheral2,052

What next?

Pembrolizumab: the full record

label, generics, price, shortages, recalls

Report a side effect to the FDA

MedWatch

Side effects hub

the most reported medicines and reactions