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Tazemetostat Side Effects

The most commonly reported side effects of tazemetostat include off label use, fatigue, and disease progression, based on 1,530 FDA adverse event reports from 2004 to 2025. 4.1% of reports found the drug to be ineffective.

Tazemetostat side effects

Percentages show how often each reaction appears relative to total reports for tazemetostat.

1
Off Label Use21.2%325
2
Fatigue20.3%311
3
Disease Progression19.7%302
4
Nausea14.4%221
5
Product Dose Omission Issue12.7%194
6
Death7.8%119
7
Diarrhoea7.3%111
8
Decreased Appetite5.9%90
9
Vomiting5.7%87
10
Asthenia5.4%83
11
Constipation4.8%74
12
Covid-194.6%71
13
Headache4.4%67
14
Alopecia4.2%65
15
Pain4.2%64

These are voluntary reports and do not establish that tazemetostat caused these reactions.

Report severity

42.4%Serious649 reports
19.7%Hospitalizations301 reports
12.7%Fatal195 reports

Seriousness is determined by the reporter, not by OpenClaim.

Tazemetostat drug interactions

Other drugs that appear in adverse event reports alongside tazemetostat. Drugs flagged as a suspected cause appear in the first column. Drugs taken at the same time but not suspected appear in the second.

Also suspected

1
Rituximab4.1%62
2
Doxorubicin-hydrochloride3.0%46
3
Lenalidomide3.0%46
4
Cyclophosphamide2.6%40
5
Vincristine-sulfate2.5%38
6
Prednisone2.2%33
7
Bendamustine-hydrochloride1.3%20
8
Etoposide1.1%17
9
Atezolizumab0.9%14
10
Paclitaxel0.8%13
11
Carboplatin0.7%11
12
Nivolumab0.7%11
13
Belinostat0.7%11
14
Prednisolone0.7%10
15
Cisplatin0.7%10

Taken alongside

1
Ondansetron28.5%436
2
Acetaminophen28.2%432
3
Ergocalciferol21.8%334
4
Aspirin16.3%249
5
Gabapentin15.3%234
6
Oxycodone14.7%225
7
Prochlorperazine13.6%208
8
Levothyroxine-sodium12.4%190
9
Acyclovir11.9%182
10
Furosemide10.5%161
11
Omeprazole10.5%160
12
Atorvastatin-calcium10.5%160
13
Metoprolol9.9%152
14
Albuterol9.9%151
15
Allopurinol9.3%143

Co-occurrence in adverse event reports does not establish a drug interaction. Patients often take multiple medications, and these lists reflect prescribing patterns rather than causal relationships. Consult a healthcare provider about potential drug interactions.

Who reports tazemetostat side effects

19.9% of tazemetostat adverse event reports involve female patients and 23.0% involve male patients. The largest age group is elderly at 47%. These figures reflect who reports side effects, not underlying risk.

Sex

Female19.9%
Male23.0%
Unknown57.1%

Age group

< 21.6%
2–117.4%
12–173.1%
18–6441.0%
65+46.9%

What is tazemetostat used for

Conditions and purposes for which patients were taking tazemetostat when the adverse event was reported.

Adenoid Cystic CarcinomaAtypical Teratoid/rhabdoid Tumour Of CnsAbdominal LymphadenopathyAcute Myeloid LeukaemiaAcute Myeloid Leukaemia RefractoryAdenocarcinoma Of ColonAdenocarcinoma PancreasAdrenal Gland CancerAgranulocytosisAngioimmunoblastic T-cell LymphomaAngiosarcomaAtypical Teratoid/rhabdoid Tumour Of CnsB-cell LymphomaB-cell LymphomaB-cell Lymphoma Stage Iii

Showing 15 of 158 indications

Tazemetostat brand names and reporting trend

Tazemetostat is sold under the brand name Tazverik.

Brand names

Tazverik195

Quarterly reports (20042025)

200420202025

An upward trend reflects increased FAERS reporting overall, not necessarily increased risk.

Taking tazemetostat with another medication?

Ask OpenClaim about your specific drug combination. Get a sourced report using FDA data, drug labels, and medical literature.