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 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.

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:

More common side effects

• blistering, crusting, irritation, itching, or reddening of the skin
• blood in urine
• cracked, dry scaly skin
• diarrhea
• fast heartbeat
• itching, pain, redness, swelling, tenderness, warmth on the skin
• loosening of the fingernails
• muscle or bone pain
• nosebleeds
• redness or soreness around the fingernails
• swelling

Less common side effects

• blurred vision
• change in vision
• difficult or labored breathing
• dizziness
• headache
• nervousness
• overbright appearance of lights
• pounding in the ears
• rapid weight gain
• seeing flashes or sparks of light
• seeing floating spots before the eyes, or a veil or curtain across part of your vision
• slow or fast heartbeat
• tightness in the chest

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:

More common side effects

• constipation
• fever
• hair loss, thinning of the hair
• loss of appetite
• nausea
• stomach pain
• swelling or inflammation of the mouth
• unusual tiredness or weakness
• vomiting

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%)

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