What to Know About Clonazepam Side Effects

Every medication comes with potential side effects, and Clonazepam is no exception. Whether you're just starting this medication or have been taking it for a while, understanding what's normal — and what's not — can help you feel more confident about your treatment.

This guide covers the most common side effects from FDA labeling, the serious ones that need immediate attention, and practical tips for managing them.

What Is Clonazepam?

Clonazepam (brand name Klonopin) is a benzodiazepine prescribed for seizure disorders and panic disorder. It works by enhancing the activity of GABA, a calming neurotransmitter in your brain. For a full overview of uses and dosing, see our guide on what Clonazepam is and how it's used.

Common Side Effects

These side effects are reported frequently in clinical trials and are usually mild to moderate. Many improve as your body adjusts to the medication over the first few weeks:

• Drowsiness and sedation — the most common side effect, reported by up to 50% of patients
• Dizziness — especially when standing up quickly
• Fatigue — feeling more tired than usual
• Impaired coordination (ataxia) — unsteadiness or clumsiness
• Memory problems — difficulty concentrating or recalling recent events
• Depression — new or worsening low mood
• Slurred speech (dysarthria)
• Decreased libido
• Increased saliva production
• Blurred vision

Most of these side effects are dose-dependent, meaning they're more likely at higher doses. Your doctor will typically start you on the lowest effective dose — 0.25 mg twice daily for panic disorder or 0.5 mg three times daily for seizures — and increase gradually.

Serious Side Effects — When to Call Your Doctor

Some side effects need immediate medical attention. Contact your doctor right away or go to the emergency room if you experience:

Respiratory Depression

This is the most dangerous side effect and is highlighted in Clonazepam's FDA Boxed Warning. Symptoms include:

• Slow, shallow, or difficult breathing
• Unusual sleepiness or difficulty waking up
• Bluish tint to lips or fingernails

The risk is significantly higher if you take Clonazepam with opioids (such as Oxycodone, Hydrocodone, or Fentanyl), alcohol, or other sedating medications. This combination can be fatal. Learn more about dangerous Clonazepam interactions.

Severe Allergic Reactions

Though rare, signs of a serious allergic reaction include:

• Swelling of the face, lips, tongue, or throat (angioedema)
• Difficulty breathing or swallowing
• Hives or severe skin rash

Seek emergency medical care immediately if these occur.

Suicidal Thoughts or Behavior

Like all anticonvulsant medications, Clonazepam carries an FDA warning about increased risk of suicidal thoughts or behavior. Contact your doctor immediately if you or a family member notice:

• New or worsening depression
• Thoughts of self-harm or suicide
• Unusual changes in mood or behavior
• Increased anxiety or agitation

If you're in crisis, call or text 988 (Suicide & Crisis Lifeline) for immediate help.

Paradoxical Reactions

In some people, especially children and older adults, Clonazepam can cause the opposite of what it's supposed to do:

• Increased agitation or aggression
• Hallucinations
• Restlessness or excitability

If this happens, contact your doctor — they may need to switch your medication.

Seizures from Withdrawal

Never stop taking Clonazepam suddenly. Abrupt discontinuation can cause withdrawal seizures, which can be life-threatening. Your doctor will taper your dose gradually when it's time to stop.

Side Effects in Specific Populations

Older Adults

People over 65 are more sensitive to Clonazepam's sedating effects. This increases the risk of falls, fractures, and confusion. Doctors typically prescribe lower doses for elderly patients.

Pregnant and Breastfeeding Women

Clonazepam is classified as Pregnancy Category D, meaning there's evidence of risk to the fetus. It may cause neonatal withdrawal symptoms and "floppy infant syndrome." It also passes into breast milk and is not recommended during breastfeeding. Talk to your doctor about alternatives if you're pregnant or planning to become pregnant.

Children

Clonazepam is FDA-approved for seizure disorders in children but not for panic disorder. Children may be more prone to paradoxical reactions like hyperactivity and aggression. They may also experience increased saliva production and drooling.

How to Manage Common Side Effects

Here are practical strategies for dealing with the most common Clonazepam side effects:

For Drowsiness and Fatigue

• Take your largest dose at bedtime if your doctor approves
• Avoid driving or operating machinery until you know how the medication affects you
• Give your body 1-2 weeks to adjust before assuming drowsiness is permanent

For Dizziness

• Stand up slowly from sitting or lying positions
• Stay hydrated
• Avoid alcohol, which makes dizziness worse

For Memory Problems

• Use a pill organizer, phone reminders, or a written schedule
• Keep a journal or notes for important tasks
• Report significant memory issues to your doctor — a dose adjustment may help

For Impaired Coordination

• Remove tripping hazards at home
• Use handrails on stairs
• Wear supportive shoes

For Depression or Mood Changes

• Track your mood daily and share this with your doctor
• Don't wait to report worsening depression — early intervention matters

Final Thoughts

Most people who take Clonazepam experience some side effects, especially in the first few weeks. The common ones — drowsiness, dizziness, fatigue — are usually manageable and often improve over time. The serious ones are rarer but important to recognize.

Keep an open line of communication with your doctor. Report any side effects that bother you or that don't go away, and never adjust your dose or stop taking Clonazepam without medical guidance.

If you're having trouble finding Clonazepam at your pharmacy due to ongoing shortages, Medfinder can help you locate it in stock near you.