Koselugo Side Effects

Generic name: selumetinib

Medically reviewed by Drugs.com. Last updated on Aug 25, 2024.

Note: This document provides detailed information about Koselugo.

Applies to selumetinib: oral capsule Side Effects associated with selumetinib. Some dosage forms listed on this page may not apply specifically to the brand name Koselugo.

Applies to selumetinib: oral capsule.

Precautions

It is very important that your doctor check your progress at regular visits. This will allow your doctor to see if the medicine is working properly and to decide if you should continue to take it. Blood and urine tests will be needed to check for unwanted effects.

Using this medicine while you are pregnant can harm your unborn baby. Use an effective form of birth control to keep from getting pregnant during treatment and for at least 1 week after your last dose. Males who are taking this medicine, with female partners who can become pregnant must use effective birth control during treatment and for at least 1 week after the last dose of this medicine. If you think you have become pregnant while using the medicine, tell your doctor right away.

This medicine may cause heart problems. Check with your doctor right away if you have chest discomfort or pain, dizziness or faintness, fast, irregular, or pounding heartbeat, swelling of the feet or lower legs, trouble with breathing, or unusual tiredness or weakness.

Check with your doctor right away if eye pain or a change in vision occurs during treatment. These could be a sign of a serious eye problem. Your doctor may want your eyes be checked by an ophthalmologist (eye doctor).

This medicine may cause diarrhea, and in some cases it can be severe. Do not take any medicine to treat diarrhea without first checking with your doctor. If you have any questions about this or if mild diarrhea continues or gets worse, check with your doctor.

Check with your doctor right away if you have a severe skin rash, acne, or redness, swelling, peeling, or tenderness of the hands or feet. These may be symptoms of a serious skin problem.

Call your doctor right away if you have dark urine, fever, muscle cramps or spasms, muscle pain or stiffness, or unusual tiredness or weakness. These could be symptoms of a serious muscle problem called rhabdomyolysis, which can cause kidney problems.

This medicine may cause bleeding problems. Tell your doctor if you have bleeding gums, coughing up blood, difficulty with breathing or swallowing, dizziness, headache, increased menstrual flow or vaginal bleeding, nosebleeds, prolonged bleeding from cuts, red or dark brown urine, or red or black, tarry stools.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal (eg, St. John's wort) or vitamin supplements.

Serious side effects of Koselugo

Along with its needed effects, selumetinib (the active ingredient contained in Koselugo) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking selumetinib:

Other side effects of Koselugo

Some side effects of selumetinib may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

For healthcare professionals

Applies to selumetinib: oral capsule.

General adverse events

The most common adverse reactions occurring in 40% of patients or greater included vomiting, rash (all types), abdominal pain, diarrhea, nausea, dry skin, fatigue, musculoskeletal pain, pyrexia, acneiform rash, stomatitis, headache, paronychia, and pruritus.^[Ref]

Cardiovascular

• Very common (10% or more): Decreased ejection fraction (up to 23%), sinus tachycardia (20%), increased blood pressure and hypertension (less than 20%)^[Ref]

Dermatologic

• Very common (10% or more): Rash, all types (up to 91%), dry skin (60%), rash acneiform (50%), paronychia including nail infection (48%), pruritus (46%), dermatitis (36%), hair changes (32%), skin infections (20%)
• Frequency not reported (events from other studies): Palmar-plantar erythrodysesthesia syndrome^[Ref]

The most common rashes included dermatitis acneiform (54%), maculopapular rash (39%), and eczema (28%).

Rashes of all types included: Dermatitis acneiform, rash maculo-papular, erythema, rash pustular, rash, urticaria, exfoliative rash, rash pruritic, rash erythematous

Rash acneiform included: Dermatitis acneiform

Dermatitis included: Dermatitis atopic, dermatitis diaper, eczema, seborrheic dermatitis, skin irritation

Hair changes included: Alopecia, hair color change

Skin infections included: Abscess, cellulitis, impetigo, and staphylococcal skin infection^[Ref]

Gastrointestinal

• Very common (10% or more): Vomiting (82%), abdominal pain (76%), diarrhea (up to 77%), nausea (up to 73%), stomatitis including mouth ulceration (50%), constipation (34%), increased lipase (32%), dry mouth (less than 20%), increased amylase (18%)
• Frequency not reported (events from other studies): Perforation, colitis, ileus, intestinal obstruction^[Ref]

Hematologic

• Very common (10% or more): Decreased albumin (51%), decreased hemoglobin (41%), decreased neutrophils (33%), decreased lymphocytes (20%)^[Ref]

Hepatic

• Very common (10% or more): Increased AST (41%), increased ALT (35%)^[Ref]

Metabolic

• Very common (10% or more): Increased potassium (27%), decreased appetite (22%), weight increased (less than 20%), decreased potassium (18%), increased alkaline phosphatase (18%), increased sodium (18%), decreased sodium (16%)^[Ref]

Musculoskeletal

• Very common (10% or more): Increased creatine phosphokinase (up to 79%), musculoskeletal pain including extremity, back, and neck pain (58%)
• Frequency not reported (events from other studies): Rhabdomyolysis^[Ref]

Nervous system

• Very common (10% or more): Headache (48%)^[Ref]

Ocular

• Very common (10% or more): Visual impairment including blurred vision, photophobia, cataracts, and ocular hypertension (less than 20%)

Uncommon events reported in other studies (0.1% to 1%): Retinal vein occlusion (RVO), retinal pigment epithelial detachment (RPED), central serous retinopathy (CSR)^[Ref]

Other

• Very common (10% or more): Fatigue and malaise/asthenia (56%), pyrexia (56%), general and localized edema including peripheral swelling (20%), facial and periorbital edema (less than 20%)^[Ref]

Respiratory

• Very common (10% or more): Epistaxis (28%), dyspnea including exertional and at rest (less than 20%)^[Ref]

Renal

• Very common (10% or more): Hematuria (22%), proteinuria (22%), acute kidney injury (less than 20%)

See also:

Further information

Koselugo side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer