Koselugo Side Effects
Generic name: selumetinib
Medically reviewed by Drugs.com. Last updated on Oct 26, 2022.
Note: This document contains side effect information about selumetinib. Some dosage forms listed on this page may not apply 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:
- Blistering, crusting, irritation, itching, or reddening of the skin
- blood in urine
- cracked, dry scaly skin
- fast heartbeat
- itching, pain, redness, swelling, tenderness, warmth on the skin
- loosening of the fingernails
- muscle or bone pain
- redness or soreness around the fingernails
- Blurred vision
- change in vision
- difficult or labored breathing
- 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:
- hair loss, thinning of the hair
- loss of appetite
- stomach pain
- swelling or inflammation of the mouth
- unusual tiredness or weakness
For Healthcare Professionals
Applies to selumetinib: oral capsule.
Very common (10% or more): Hemoglobin decreased (41%), neutrophils decreased (33%), lymphocytes decreased (20%)
Very common (10% or more): Blurred vision, photophobia, cataracts, and ocular hypertension (15%), visual impairment
Frequency not reported: Retinal vein occlusion (RVO), retinal pigment epithelial detachment (RPED)[Ref]
Very common (10% or more): Albumin decreased (79%), anorexia (22%), increased/decreased potassium (18%), amylase increased (18%), sodium increased (18%), sodium decreased (16%), weight increased[Ref]
Very common (10% or more): AST increased (41%), ALT increased (35%), alkaline phosphatase increased (18%), acute kidney injury[Ref]
The most common adverse reactions (40% or greater) were vomiting, rash (all), abdominal pain, diarrhea, nausea, dry skin, fatigue, musculoskeletal pain, pyrexia, acneiform rash, stomatitis, headache, paronychia, and pruritus.[Ref]
Very common (10% or more): Headache (48%)[Ref]
Very common (10% or more): Rash (e.g., dermatitis acneiform, rash maculopapular, erythema, rash pustular, urticaria, exfoliative rash, rash pruritic, rash erythematous, eczema) (91%), dry skin (60%), rash acneiform (dermatitis acneiform) (50%), paronychia (e.g., paronychia, nail infection) (48%), pruritus (46%), dermatitis (e.g., dermatitis, dermatitis atopic, dermatitis diaper, eczema, seborrheic dermatitis, skin irritation) (36%), hair changes (e.g., alopecia, hair color change) (32%)
Frequency not reported: Palmar-plantar erythrodysesthesia syndrome[Ref]
Very common (10% or more): Vomiting (82%), abdominal pain (76%), diarrhea (70%), nausea (66%), stomatitis (e.g., stomatitis, mouth ulceration) (50%), constipation (34%), lipase increased (32%), dry mouth, GI perforation, colitis, ileus, intestinal obstruction[Ref]
More about Koselugo (selumetinib)
- Check interactions
- Pricing & coupons
- Reviews (1)
- Drug images
- Dosage information
- During pregnancy
- FDA approval history
- Drug class: multikinase inhibitors
- En español
Related treatment guides
1. "Product Information. Koselugo (selumetinib)." Astra-Zeneca Pharmaceuticals (2020):
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
Some side effects may not be reported. You may report them to the FDA.