What are the side effects of pemetinib? Common adverse reactions and countermeasures

Pemigatinib is an oral targeted drug mainly used to treat cancers with FGFR (fibroblast growth factor receptor) mutations or amplifications, especially certain types of cholangiocarcinoma. Although it has achieved certain clinical efficacy, it may also cause some side effects. Here are common side effects and what to do about them:
1. Liver-related adverse reactions
Pemetinib may cause liver function abnormalities, manifested by elevated serum aminotransferases (AST, ALT). Such adverse reactions are common in clinical practice, especially in patients receiving high-dose therapy. Liver damage may be asymptomatic, but if left unchecked for a long time, it may cause more serious liver problems, such as jaundice or liver failure.
Countermeasures: During treatment with pemetinib, patients need to regularly check liver function, especially ALT and AST levels. If obvious liver function abnormalities occur, it is recommended to stop the drug immediately and carry out corresponding treatment. Patients with severe hepatic impairment should avoid using this drug and other alternative treatments may be considered if necessary.
2. Eye problems
Pemetinib may cause ocular adverse reactions, such as blurred vision, dry eyes, eye pain, or other retina-related problems. The mechanism of eye side effects is related to the drug's inhibitory effect on vascular endothelial growth factor (VEGF), which may affect the health of eye blood vessels.

Countermeasures: Patients should undergo regular eye examinations while receiving pemetinib, especially during the first few months of drug treatment. If patients experience vision changes, seek medical advice as soon as possible and consider suspending or adjusting the dose of treatment. This drug should be used with caution in patients with a history of eye disease, especially those at higher risk for retinopathy.

3. Gastrointestinal discomfort
Gastrointestinal reactions are common side effects of pemetinib treatment and include nausea, vomiting, diarrhea, and decreased appetite. These reactions may affect the patient's daily life and compliance with treatment. Gastrointestinal discomfort usually occurs early in treatment, and some patients may experience relief as treatment progresses.
Countermeasures: To relieve gastrointestinal discomfort, patients can take pemetinib with food to reduce gastrointestinal irritation. If nausea and vomiting are severe, antiemetic medications may be used. Patients with diarrhea should increase their fluid intake to prevent dehydration. If symptoms persist or worsen, a doctor should be consulted and treatment or medication dosage may need to be adjusted.
4. Skin reactions
Rash and hair loss are other common side effects of pemetinib. Some patients may develop a mild rash characterized by erythema, itching, or dry skin. Hair loss is usually temporary and may resolve on its own after treatment ends.
What to do: For people with rash or itching, topical anti-allergic medications or moisturizers can be used to relieve symptoms. If the rash is severe and affects quality of life, it may be necessary to consider suspending or adjusting drug treatment. For hair loss, patients should be aware that this side effect is usually temporary and may resolve after treatment is completed.
5. Hypercalcemia
Hypercalcemia is a possible side effect of pemetinib treatment and manifests as loss of appetite, nausea, vomiting, constipation, extreme fatigue, and renal impairment. The mechanism of hypercalcemia is related to the inhibitory effect of drugs on FGFR, which may lead to abnormal increases in calcium ions in the body.
Countermeasures: For patients with hypercalcemia, blood calcium levels should be detected promptly and corresponding treatment measures should be taken, such as rehydration therapy or the use of drugs to reduce blood calcium levels. In some severe cases, the drug may need to be temporarily stopped and blood calcium levels controlled with medications or other treatments.
Although pemetinib has good efficacy in treating cancer, its side effects cannot be ignored. Abnormal liver function, eye problems, gastrointestinal discomfort, skin reactions, and hypercalcemia are common side effects. When using this drug, patients should undergo regular examinations and take preventive and response measures according to the doctor's recommendations. In addition, doctors should adjust the dosage or change drugs according to the patient's specific conditions to ensure the therapeutic effect and minimize the occurrence of side effects.
Reference: https://go.drugbank.com/drugs/DB15102