Prescription medication · Benzodiazepine
clonazepam
Also sold as Klonopin. Clonazepam is used to treat certain seizure disorders, including Lennox-Gastaut syndrome, akinetic, and myoclonic seizures.
Data updated 2026-05-15
- 155,147
- FDA reportsHeavily reported
- 14
- InteractionsSeveral interactions
- 80% less
- Generic vs brandHuge savings
- In shortage
- FDA status
What the data shows
clonazepam (Klonopin) is a prescription Benzodiazepine, more reported than roughly 9 in 10 tracked drugs (155,147 FDA reports), whose generic runs roughly half the brand price or less (80% less).
Reporting volume reflects how widely a drug is used and studied, not how dangerous it is, a FAERS report documents a temporal association, never proof of cause.
clonazepam (Klonopin) is a prescription Benzodiazepine. Clonazepam is used to treat certain seizure disorders, including Lennox-Gastaut syndrome, akinetic, and myoclonic seizures.
Clonazepam is a medicine that belongs to the benzodiazepine class. It is used to treat seizure disorders and panic disorder.
Verify with FDA → · CMS NADAC pricing →
Drug Shortage Alert
clonazepam is currently listed as in shortage by the FDA. Affected manufacturer: Aurobindo Pharma USA. Status: Available.
View all drug shortages →Drug Pricing (NADAC)
Brand Price
$2.45/unit
Generic Price
$0.49/unit
Generic Savings
80%
Generic Available
Yes (9 manufacturers)
Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →
What it does
Clonazepam is used to treat certain seizure disorders, including Lennox-Gastaut syndrome, akinetic, and myoclonic seizures.
Common side effects
Drowsiness, Problems with coordination
Key warnings
Taking clonazepam with opioid medicines can cause very serious problems, including slowed breathing, coma, and death.
The sections below are summarized in plain English from clonazepam's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.
How It Works
Clonazepam works by affecting chemicals in your brain that may be unbalanced. It enhances the effects of a natural brain chemical called GABA. This helps to reduce seizures and relieve panic symptoms.
How to Take It
Take clonazepam tablets by swallowing them whole with water. For seizures, adults usually start with 1.5 mg per day, divided into three doses. Your doctor may increase the dose by 0.5 to 1 mg every 3 days until your seizures are controlled. For panic disorder, adults usually start with 0.25 mg twice daily.
This is a plain-language summary of clonazepam's FDA labeling, not individualized dosing advice. Ask a pharmacist or prescriber before changing how you take this medication.
Pregnancy & Breastfeeding
Clonazepam may harm an unborn baby. Talk to your doctor if you are pregnant or plan to become pregnant. Clonazepam can pass into breast milk and may harm a nursing infant.
This is a plain-language summary of clonazepam's FDA labeling, not individualized advice. Ask a pharmacist or prescriber about pregnancy or breastfeeding on this medication.
Missed Dose
If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and continue with your regular schedule.
This is a plain-language summary of clonazepam's FDA labeling, not individualized advice. Ask a pharmacist or prescriber what to do about your specific missed dose.
Storage
Store clonazepam tablets at room temperature, between 68°F and 77°F.
Side Effects (from patient reports)
Based on 155,147 FDA adverse event reports.
Most-reported reactions
Adverse reactions in FAERS for clonazepam, by number of reports
- Tiredness
Tiredness
10,238 reports
- Feeling sick to your stomach
Feeling sick to your stomach
9,567 reports
- Worry or nervousness
Worry or nervousness
8,735 reports
- Head pain
Head pain
8,596 reports
- Feeling sad or hopeless
Feeling sad or hopeless
8,123 reports
- Discomfort
Discomfort
8,037 reports
- Feeling unsteady
Feeling unsteady
7,248 reports
- Trouble sleeping
Trouble sleeping
7,010 reports
- Shortness of breath
Shortness of breath
6,826 reports
- Accidentally falling down
Accidentally falling down
6,625 reports
What this shows Bars show how often each reaction was reported, not how likely it is to happen, a report records a temporal association, never proof that the drug caused it.
Reports over time
Adverse-event reports filed for clonazepam each year to the FDA Adverse Event Reporting System (FAERS).
Year-to-year volume tracks usage, prescribing, and scrutiny, not a change in per-patient risk. Source: FDA FAERS.
Where clonazepam sits
clonazepam has more FDA adverse-event reports than 92% of the drugs FAERS tracks. A high position reflects how widely a drug is used and watched, not how dangerous it is.
Percentile across all drugs PlainMeds tracks by FAERS report volume. The dot is clonazepam; the line is the median (50th percentile).
FDA Adverse Event Report Analysis
Detailed analysis of 155,147 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 2002–2025.
Total Reports
155,147
Reports Mentioning Death
18,179
11.7% of reports — not proof of cause
Hospitalization Reports
46,031
Top Indication
Product Used For Unknown Indication
Gender Distribution
Age Distribution
Most Reported Adverse Reactions (FAERS)
| # | Reaction | Reports |
|---|---|---|
| 2 | FATIGUE | 10,236 |
| 3 | NAUSEA | 9,564 |
| 4 | ANXIETY | 8,735 |
| 5 | HEADACHE | 8,590 |
| 6 | DEPRESSION | 8,121 |
| 7 | PAIN | 8,033 |
| 9 | DIZZINESS | 7,245 |
| 10 | INSOMNIA | 7,008 |
| 11 | DYSPNOEA | 6,826 |
| 12 | FALL | 6,625 |
| 13 | DIARRHOEA | 6,606 |
| 14 | VOMITING | 6,214 |
| 15 | MALAISE | 5,976 |
| 16 | SOMNOLENCE | 5,590 |
| 17 | TOXICITY TO VARIOUS AGENTS | 5,182 |
Reactions in Death Reports
Reactions in Hospitalization Reports
Source: FDA FAERS (Adverse Event Reporting System) FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation
Serious Warnings
Taking clonazepam with opioid medicines can cause very serious problems, including slowed breathing, coma, and death. Only take these medicines together if there are no other options. Clonazepam can be habit-forming, leading to abuse, misuse, and addiction, which can result in overdose or death. Stopping clonazepam suddenly can cause dangerous withdrawal symptoms. Your doctor will slowly lower your dose to prevent withdrawal.
Known Drug Interactions
The selective serotonin reuptake inhibitors sertraline (weak CYP3A4 inducer) and fluoxetine (CYP2D6 inhibitor), and the anti-epileptic drug felbamate (CYP2C19 inhibitor and CYP3A4 inducer) do not affect the pharmacokinetics of clonazepam.
Mechanism: Sertraline does not interfere with how your body breaks down or uses clonazepam.
What to do: These medications can generally be taken together without needing to change your dose.
The selective serotonin reuptake inhibitors sertraline (weak CYP3A4 inducer) and fluoxetine (CYP2D6 inhibitor), and the anti-epileptic drug felbamate (CYP2C19 inhibitor and CYP3A4 inducer) do not affect the pharmacokinetics of clonazepam.
Mechanism: Fluoxetine does not interfere with how your body breaks down or uses clonazepam.
What to do: These medications can generally be taken together without needing to change your dose.
The selective serotonin reuptake inhibitors sertraline (weak CYP3A4 inducer) and fluoxetine (CYP2D6 inhibitor), and the anti-epileptic drug felbamate (CYP2C19 inhibitor and CYP3A4 inducer) do not affect the pharmacokinetics of clonazepam.
Mechanism: Felbamate does not change the levels of clonazepam in the body or how it is processed.
What to do: These medications can be used together because they do not have a significant interaction.
Although early studies reported an increased risk of congenital malformations with diazepam and chlordiazepoxide, there was no consistent pattern noted.
Mechanism: These drugs are both sedatives that slow down your brain and body. Taking them together can make you dangerously sleepy or cause trouble breathing.
What to do: Do not take these two medicines at the same time unless your doctor tells you to.
Cytochrome P450 inducers, such as phenytoin, carbamazepine, lamotrigine, and phenobarbital induce clonazepam metabolism, causing an approximately 38% decrease in plasma clonazepam levels.
Mechanism: Lamotrigine speeds up the process of clearing clonazepam from your body. This results in lower levels of clonazepam in your bloodstream.
What to do: Your doctor may need to adjust your clonazepam dose to ensure the medicine stays effective.
This is a plain-language summary of interactions documented in FDA labeling, not individualized advice. Ask a pharmacist or prescriber before combining medications.
Common Questions
Can I drink alcohol while taking clonazepam?
How long does it take for clonazepam to start working?
Can I drive while taking clonazepam?
What should I do if I feel like clonazepam is not working anymore?
Can I take other medications with clonazepam?
Is it safe to stop taking clonazepam suddenly?
What are the symptoms of clonazepam withdrawal?
Can clonazepam cause weight gain?
Does clonazepam interact with any foods?
What should I do if I overdose on clonazepam?
What are the common side effects of clonazepam?
Does clonazepam interact with other medications?
What drug class is clonazepam?
Is there a generic version of clonazepam?
Is clonazepam safe during pregnancy?
Has clonazepam been recalled?
Is clonazepam currently in shortage?
Active Recalls
Labeling: Label Error on Declared Strength; Some cartons were incorrectly labeled. The blister strips inside the product carton reflect the correct strength.
Endo USA, Inc.
Labeling: Label Error on Declared Strength; Some cartons were incorrectly labeled. The blister strips inside the product carton reflect the correct strength.
Endo USA, Inc.
Related Medications in Benzodiazepine
Other drugs grouped near clonazepam - same-class peers and common alternatives.
brivaracetam
Briviact
Brivaracetam is a medicine used to treat partial-onset seizures.
Compare with clonazepam →
cannabidiol
Epidiolex
Epidiolex is a medicine that contains cannabidiol.
Compare with clonazepam →
carbamazepine
Tegretol
Carbamazepine is a medicine used to control seizures and treat nerve pain.
Compare with clonazepam →
cenobamate
Xcopri
Xcopri is a medicine used to treat partial-onset seizures in adults.
Compare with clonazepam →
clobazam
Onfi, Sympazan
Clobazam oral suspension is a medicine used with other medicines to treat seizures caused by Lennox-Gastaut syndrome.
Compare with clonazepam →
Medication Guides
Understanding Drug Interactions
How CYP450 enzymes, inhibitors, and inducers affect your medications
Generic vs Brand Name Drugs
FDA requirements, cost savings, and when the difference matters
Narrow Therapeutic Index Drugs
Why some drugs demand precise dosing and monitoring
Common Drug Interactions
Dangerous medication combinations and how to protect yourself
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What the FDA Data Shows for clonazepam
The FDA label for clonazepam (sold under brand names such as Klonopin) classifies it as a prescription-only medication in the Benzodiazepine class. Clonazepam is used to treat certain seizure disorders, including Lennox-Gastaut syndrome, akinetic, and myoclonic seizures. Official labeling lists 2 commonly reported side effects, including Drowsiness, Problems with coordination.
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 155,147 voluntary reports. The database also lists 14 documented drug interactions derived from FDA labeling, with the top-flagged interaction rated major severity. NADAC pricing from CMS shows a generic unit cost of $0.49 versus $2.45 for the brand - a 80% generic savings.
Report counts do not establish causation, a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history (currently 2 recall records on file), and patent information further shape supply and switching decisions. This page summarizes public FDA data for educational purposes only and is not a substitute for professional medical advice, always consult a licensed healthcare provider before starting, stopping, or changing any medication.
Data Sources
Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC). Shortage status: FDA Drug Shortages Database.
FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. Always consult a healthcare professional before making medication decisions.
Last updated: January 2, 2026
Read our methodology - how this data is sourced, computed, and verified.
Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled and last refreshed May 2026. See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a correction.
All federal data sources used on this page
- FDA Orange Book - approved drug products with therapeutic equivalence. accessdata.fda.gov/cder/ob
- FDA DailyMed - NIH-hosted drug labeling for FDA-approved meds. dailymed.nlm.nih.gov
- FDA Adverse Event Reporting System (FAERS) - post-marketing safety surveillance. fda.gov/drugs/faers
- NLM RxNorm - standardized clinical drug nomenclature. nlm.nih.gov/research/umls/rxnorm
- CMS Medicare Part B Drug Average Sales Price Files - federal drug pricing data. cms.gov/medicare/part-b-drugs/asp
- FDA Drug Shortages Database - current and resolved drug shortage tracking. accessdata.fda.gov/drugshortages