Are the side effects of pemetinib serious? What are some ways to relieve discomfort?

Pemigatinib is an oral small molecule inhibitor targeting fibroblast growth factor receptor (FGFR) mutations. It is mainly used to treat patients with cholangiocarcinoma carrying FGFR2 gene fusion or rearrangement. It also shows certain efficacy in some hematological malignancies and other solid tumors. However, like most targeted drugs, pemetinib may also cause a series of adverse reactions while exerting its therapeutic effect. Some patients have obvious side effects, so it is necessary to pay close attention and take appropriate measures to mitigate them.

Common side effects of pemetinib

The side effects of pemetinib mainly include hyperphosphatemia, gastrointestinal discomfort, ocular toxicity, skin and nail changes, abnormal liver function, etc., as follows:

1.Hyperphosphatemia

One of the most common side effects of pemetinib is hyperphosphatemia, an increase in blood phosphate levels. This is because FGFR inhibitors interfere with phosphorus metabolism, leading to increased phosphate reabsorption in the body. Hyperphosphatemia may cause vascular calcification, impaired kidney function, and bone disease in some cases.

2.Gastrointestinal discomfort

Many patients will experience symptoms such as nausea, vomiting, diarrhea or constipation during the use of pemetinib, which affects appetite and digestive function and even leads to weight loss.

3.Ocular toxicity

Pemetinib may affect eye health, causing dry eyes, blurred vision, photophobia, and in some cases retinopathy, so patients need regular eye exams.

4.Skin and nail changes

Pemetinib may cause dry skin, rash, pigmentation changes, and affect nail growth, causing nails to be brittle, brittle, or even fall off.

5.Abnormal liver function

Some patients will experience elevated liver enzymes after taking pemetinib. Long-term use may cause a certain burden on the liver, so liver function needs to be monitored regularly.

6.Other side effects

Other possible adverse reactions include fatigue, hair loss, mouth sores, muscle or joint pain, and some patients may feel depressed or anxious.

How to alleviate the side effects of pemetinib?

Regarding the adverse reactions of pemetinib, taking reasonable monitoring and management measures can effectively reduce discomfort and help patients better tolerate the treatment.

1.Control hyperphosphatemia

Serum phosphorus levels should be monitored regularly during pemetinib treatment, especially during the first 2-4 weeks of treatment, as the increase in serum phosphorus is most obvious at this time.

Low-phosphorus diet: Reduce the intake of phosphorus-rich foods such as dairy products, nuts, red meat, and whole grains.

If necessary, your doctor may recommend the use of phosphate binders (such as lanthanum carbonate, calcium acetate) to lower blood phosphorus levels.

2.Relieve gastrointestinal discomfort

Nausea and vomiting: Antiemetics (such as ondansetron) can be used under the guidance of a doctor.

Diarrhea: Stay hydrated and use an antidiarrheal medicine (such as loperamide).

Constipation: Increase dietary fiber intake, such as vegetables, fruits, and whole grains, and exercise moderately.

3.Preventing and managing ocular toxicity

Periodic eye exams are recommended before and during treatment, especially for patients with pre-existing vision problems or eye disease.

Keep your eyes moist and use artificial tears to relieve dry eye symptoms.

Avoid looking at electronic screens for long periods of time to reduce eye fatigue.

If severe vision loss or retinopathy occurs, you should consult your doctor immediately and consider adjusting the dose or suspending the medication.

4.Protect skin and nails

Use moisturizing skin care products to relieve dry and flaky skin.

Avoid sun exposure, and it is recommended to apply sunscreen when going out and wear a hat or sunglasses to reduce pigmentation and skin damage.

Nail care: Avoid excessive trimming of nails and reduce exposure to chemicals such as detergents.

5.Monitor liver function

It is recommended to draw blood regularly to check liver function (ALT, AST, etc.), especially patients with a history of liver disease need to be more cautious.

Avoid alcohol intake to reduce additional burden on the liver.

6.Improve fatigue and hair loss

Get enough sleep and rest, adjust your work and rest schedule to avoid overexertion.

Moderate exercise can improve physical strength and relieve fatigue, such as yoga, walking, and light strength training.

Balanced nutrition and intake of foods rich in iron, zinc and protein can help reduce hair loss.

Pemetinib has good efficacy in the treatment of cholangiocarcinoma and other tumors, but it may also cause side effects such as hyperphosphatemia, gastrointestinal reactions, ocular toxicity, skin and nail changes, and abnormal liver function. Most side effects can be alleviated with dietary modifications, medication management, regular monitoring, and lifestyle improvements. For patients with more severe symptoms, doctors may adjust the dose or suspend treatment. Therefore, while taking pemetinib, patients should pay close attention to their physical changes and maintain communication with their doctors to ensure safe and effective treatment.

Reference materials:https://go.drugbank.com/drugs/DB15102