Common Side Effects of Cometriq
Cometriq (cabozantinib), used for medullary thyroid cancer, causes side effects in most patients. The most frequent include diarrhea (affecting over 50% of users), nausea, fatigue, decreased appetite, hypertension, vomiting, weight loss, hand-foot syndrome (redness or pain on palms and soles), and constipation. Hair color changes and taste alterations also occur often.[1][2]
Serious Side Effects and Risks
Serious issues can arise, including severe hypertension (up to 36% of patients), bleeding events (like gastrointestinal hemorrhage), blood clots (deep vein thrombosis or pulmonary embolism), heart problems (such as heart attack or stroke), perforated gastrointestinal ulcers, and severe liver damage. Fistulas (abnormal connections between organs) and wound healing delays post-surgery are risks too. These led to treatment discontinuation in about 16% of trial participants.[1][2][3]
Side Effects by Frequency
- Very common (≥30%): Diarrhea, nausea, fatigue, palmar-plantar erythrodysesthesia.[1]
- Common (10-29%): Hypertension, decreased appetite, vomiting, dysphonia (voice changes), asthenia, abdominal pain.[1]
- Less common but severe: Proteinuria (kidney protein loss), reversible posterior leukoencephalopathy syndrome (RPLS, causing headaches and confusion), osteonecrosis of the jaw.[2][3]
Patients often need dose reductions (79% in trials) or interruptions due to these.[1]
How Side Effects Are Managed
Doctors monitor blood pressure closely and adjust doses for toxicity. Antidiarrheals like loperamide help with diarrhea; antihypertensives control blood pressure. Avoid starting in patients with uncontrolled hypertension or recent bleeding. Regular liver function tests are required.[1][2]
Long-Term and Rare Side Effects
Prolonged use raises risks of hypothyroidism (low thyroid function), dental issues, and embryo-fetal toxicity (contraindicated in pregnancy). Rare reports include allergic reactions, seizures, and eye problems like corneal perforations.[2][3]
Patient Experiences and Comparisons
In clinical trials, 33% stopped treatment due to side effects, higher than some other tyrosine kinase inhibitors like vandetanib (16%). Patients report diarrhea and hand-foot syndrome as most disruptive daily.[3]
Sources
[1]: Cometriq Prescribing Information (FDA)
[2]: Drugs.com - Cometriq Side Effects
[3]: Medscape - Cabozantinib Side Effects