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Clonazepam Side Effects

The most commonly reported side effects of clonazepam include fatigue, off label use, and nausea, based on 159,324 FDA adverse event reports from 2004 to 2025. 7.7% of reports found the drug to be ineffective.

#1 Reported: FatigueAll side effects ↓Top Co-Medication: Quetiapine-fumarateDrug interactions ↓72% of Reports Are AdultDemographics ↓

Clonazepam side effects

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

1
Drug Ineffective7.7%12,300
2
Fatigue5.4%8,659
3
Off Label Use4.7%7,522
4
Nausea4.7%7,431
5
Headache4.4%6,970
6
Anxiety4.3%6,915
7
Pain4.1%6,563
8
Depression3.9%6,167
9
Dizziness3.5%5,629
10
Dyspnoea3.5%5,625
11
Diarrhoea3.5%5,517
12
Fall3.4%5,495
13
Insomnia3.4%5,419
14
Malaise3.2%5,160
15
Toxicity To Various Agents3.2%5,067

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

Report severity

67.6%Serious107,746 reports
29.4%Hospitalizations46,795 reports
11.8%Fatal18,851 reports

Seriousness is determined by the reporter, not by OpenClaim.

Clonazepam drug interactions

Other drugs that appear in adverse event reports alongside clonazepam. 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
Quetiapine-fumarate5.4%8,656
2
Sodium-oxybate3.7%5,869
3
Adalimumab3.1%4,963
4
Pregabalin3.1%4,895
5
Lamotrigine2.8%4,432
6
Acetaminophen2.7%4,304
7
Gabapentin2.6%4,138
8
Levetiracetam2.5%3,963
9
Bupropion2.4%3,844
10
Olanzapine2.4%3,803
11
Aripiprazole2.3%3,646
12
Oxycodone2.1%3,275
13
Sertraline-hydrochloride1.9%3,003
14
Diazepam1.9%2,979
15
Risperidone1.8%2,842

Taken alongside

1
Acetaminophen14.1%22,465
2
Gabapentin11.3%17,945
3
Levothyroxine-sodium11.1%17,621
4
Ergocalciferol11.0%17,508
5
Aspirin9.3%14,741
6
Omeprazole8.8%14,049
7
Albuterol8.3%13,240
8
Atorvastatin-calcium6.9%10,996
9
Trazodone-hydrochloride6.7%10,675
10
Fluticasone6.3%10,009
11
Duloxetine-hydrochloride6.2%9,922
12
Oxycodone6.1%9,751
13
Bupropion6.1%9,717
14
Sertraline-hydrochloride6.1%9,708
15
Hydrocodone5.8%9,166

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 clonazepam side effects

60.4% of clonazepam adverse event reports involve female patients and 32.8% involve male patients. The largest age group is adult at 72%. These figures reflect who reports side effects, not underlying risk.

Sex

Female60.4%
Male32.8%
Unknown6.8%

Age group

< 21.1%
2–112.0%
12–171.9%
18–6471.8%
65+23.2%

What is clonazepam used for

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

Abdominal DiscomfortAbdominal DistensionAbdominal PainAbdominal Pain UpperAbdominal RigidityAbnormal BehaviourAbnormal DreamsAbnormal GaitAbnormal Sleep-related EventAccidental Drug Intake By ChildAccidental ExposureAccidental Exposure To ProductAccidental OverdoseAccidental PoisoningAcne

Showing 15 of 1,544 indications

Clonazepam brand names and reporting trend

Clonazepam is sold under the brand name Klonopin Rapidly Disintegrating.

Brand names

Klonopin Rapidly Disintegrating132,245

Quarterly reports (2004–2025)

20052010201520202025

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

Taking clonazepam with another medication?

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

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