Clonazepam vs Xanax: A Side by Side Comparison

Panic disorder is a type of anxiety disorder that is estimated to affect approximately 4.7 percent of adults in the United States at some point in their lifetimes.

The condition can be extremely debilitating, as there is no obvious cause for the panic attacks that are experienced as part of the condition. 

Medications like clonazepam and Xanax are two of the drugs available for the treatment of panic disorder. 

To help patients decide which medication might offer the most benefit for their panic disorder, we’ve put together a side by side comparison of clonazepam vs. Xanax.

Drug Class

Xanax, (sold under the generic name alprazolam) and clonazepam (sold under the brand name Klonopin) both belong to a class of drugs called benzodiazepines, commonly referred to as benzos. 

Other medications that also belong to this drug class include Ativan and Valium, both of which are also used for the treatment of certain types of anxiety.   

Clonazepam is available in the form of either an oral tablet that is swallowed or an oral disintegrating tablet, which dissolves in the mouth.

Xanax is only available as an oral tablet and is available as both an immediate-release and extended-release formula.

Conditions Treated

Clonazepam and Xanax are both FDA-approved to treat panic disorder, which is a specific type of anxiety disorder.

Clonazepam is also FDA-approved for the treatment of certain seizure disorders, including absence seizures and Lennox-Gastaut syndrome.

However, unlike Xanax, Clonazepam is not approved for the short-term relief of general anxiety symptoms.

Xanax is FDA-approved for the treatment of anxietydisorders, short-term relief of symptoms of anxiety, anxiety associated with depression, and panic disorder.

Panic Disorder

Clonazepam and Xanax are both used to treat panic disorder, which can develop from sudden, recurrent panic attacks. 

Panic attacks are characterized by episodes of sudden, intense fear and anxiety that can produce physical symptoms even without an obvious cause or presence of serious danger.

Panic attacks are so overwhelming that some people feel like they are having a heart attack during the experience. 

Although many people may experience one or two panic attacks over the course of their lifetimes, such as when finding out about the death of a loved one, people that experience panic attacks on a recurring basis are diagnosed with panic disorder. 

Symptoms of panic attacks include:

  • Sense of impending doom or danger
  • Nausea
  • Chest pain
  • Rapid, pounding heart rate
  • Trembling or shaking
  • Chills
  • Fear of loss of control 
  • Sweating
  • Shortness of breath or tightness in your throat
  • Dizziness, lightheadedness or faintness
  • Feeling detached from reality
  • Abdominal cramping
  • Headache
  • Hot flashes
  • Numbness or tingling sensation


Clonazepam and Xanax differ in how quickly the medications take effect and how long they last.

In general, Xanax is absorbed more quickly than clonazepam. However, clonazepam generally lasts longer in the body than Xanax. 

Clonzepam works longer than most of the other drugs in its class. Clonazepam reaches peak levels in the body within 1 to 4 hours.

The half-life of clonazepam is about 30 to 40 hours, and the medication can be detected in the body for up to two weeks, depending on the dosage. 

By contrast, Xanax starts working faster than clonazepam. Xanax reaches peak levels in the body within 1 to 2 hours.

The half-life of Xanax is shorter than that of clonazepam at an average of 11 hours. The absorption rate of Xanax can be influenced by a person’s age and race.

Studies show that Xanax lasts about 25 percent longer in people of Asian descent compared to patients of Caucasian descent. People over the age of 65 will also find that the effects of the drug last longer.  

Whether you choose to take clonazepam or Xanax to treat your panic disorder, you may need to take more than one dose of Xanax or clonazepam during the day in order to keep panic attacks at bay for a full 24 hours. 

Risks and Warnings

Both clonazepam and Xanax present a high risk of physical and psychological dependence.

Due to their habit-forming nature, the drugs should be taken for the shortest period of time possible and at the lowest possible dose for symptom management. 

People with a previous history of addiction to drugs or alcohol and those with addictive tendencies are more likely to abuse clonazepam and Xanax and should use caution when taking these medications.

Addiction treatment may be necessary for certain individuals who abuse the substances.

Both clonazepam and Xanax may cause symptoms of depression to worsen in people who are suffering from the condition and can cause suicidal thoughts. 

Clonazepam and Xanax act on the central nervous system in order to produce a sedative effect. When combined with other central nervous system depressants, clonazepam and Xanax can cause severe respiratory depression, or rapid, shallow breathing, which may warrant immediate medical attention.

Make sure to tell your doctor and pharmacist about any prescription drugs, over-the-counter medications, supplements, vitamins, or herbs you are taking in order to ensure that nothing you are taking will heighten the effects of either drug.

Clonazepam and Xanax should not be used by pregnant or breastfeeding mothers due to the potential for serious birth defects and life-threatening withdrawal symptoms for the infant.

Side Effects

Side effects for both Xanax and clonazepam can be categorized as common, less common, and serious.  Common side effects of Xanax include:

  • Skin rash
  • Weight gain
  • Memory impairment
  • Blurred vision
  • Diarrhea
  • Anxiety 
  • Weight loss
  • Dysarthria
  • Fatigue
  • Cognitive dysfunction
  • Constipation
  • Increased appetite
  • Insomnia 
  • Decreased libido
  • Decreased appetite
  • Ataxia
  • Difficulty in micturition
  • Drowsiness

Common side effects of clonazepam include: 

  • Drowsiness
  • Problems with coordination
  • Increased saliva production
  • Blurred vision
  • Dizziness
  • Frequent urination
  • Unsteadiness
  • Difficulty thinking or remembering
  • Muscle or joint pain
  • Changes in sex drive, or libido

Less common side effects of Xanax include:

  • Low blood pressure
  • Manic behavior
  • Muscle twitching
  • Decreased lung function

Less common side effects of clonazepam include:

  • Rash
  • Hives
  • Anemia
  • Seizures
  • Abnormal liver function tests
  • Decreased blood platelets
  • Manic behavior
  • Changes in libido

Serious side effects of both Xanax and clonazepam are associated with depression of the central nervous system. Serious side effects associated with both drugs include:

  • Slowed breathing
  • Respiratory failure
  • Suicidal thoughts
  • Psychological and physical dependence
  • Serious allergic reaction (antihistamines may be needed)

Both clonazepam and Xanax carry a high risk of physical and psychological dependence.

The best way to avoid dependency on the medications is to take them exactly as prescribed; however, it’s also important to keep an eye out for symptoms of dependence. Symptoms of dependence for both clonazepam and Xanax may include:

  • Body aches
  • Anxiety
  • Depression 
  • Muscle weakness
  • Sweating
  • Nightmares
  • Nausea
  • Vomiting 

Some patients may be allergic to certain ingredients in clonazepam and Xanax. If you notice any of the following symptoms of an allergic reaction, make sure to seek immediate medical treatment: 

  • Rash or hives
  • Trouble breathing or swallowing
  • Swelling of lips, tongue, or face
  • Rapid heartbeat

This may not be a complete list of side effects.


Like other benzodiazepines, both clonazepam and Xanax can be habit forming.

Your risk of developing a dependence on either medication increases as the drugs are used for longer periods of time and in higher doses.  

Patients who take either medication for longer than two weeks may experience withdrawal symptoms due to physical and psychological dependence on the drug if the medication is abruptly discontinued.  

The longer you have taken the medication, the more likely you are to experience withdrawal symptoms after discontinuing the medication. 

Patients who are looking to decrease their dose or stop taking their medication should do so under the guidance of a healthcare professional. 

Common withdrawal symptoms may include:

  • Convulsions
  • Cramps
  • Vomiting
  • Sweating
  • Insomnia
  • Tremors

It is possible to become severely dependent on both clonazepam and Xanax, particularly when the medications are abused.

People with severe dependency may experience severe withdrawal symptoms. 

Serious signs of withdrawal include: 

  • Hallucinations
  • Seizures
  • Panic attacks


Benzodiazepines like clonazepam and Xanax may carry a high risk of overdose, particularly when combined with alcohol, opioid medications, or other central nervous system depressants. 

When taken for longer than the prescribed amount of time, patients may find that they need to take their medication in higher doses than prescribed in order to achieve the same sedative effect. 

As a result, overdose is more common in people who abuse the medication or take it differently than prescribed. 

Signs of substance abuse include: 

  • Slurred speech
  • Feeling restless
  • Loss of balance or coordination
  • Confusion
  • Slow heartbeats
  • Extreme drowsiness
  • Muscle weakness
  • Weak or shallow breathing 
  • Lightheadedness
  • Coma

If you or someone you know is experiencing symptoms of overdose from clonazepam or Xanax, make sure that you seek medical advice immediately. 


Both clonazepam and Xanax are effective medications for the treatment for panic disorder. Which drug works best for each patient will vary depending on their specific condition and medical history, but both medications have been shown to be effective.

Clonazepam and Xanax are both available in both generic and brand name forms of the medications, and patients can save on their prescriptions by using a pharmacy discount card from

References, Studies and Sources:

author avatar
Angel Rivera
I am a Bilingual (Spanish) Psychiatrist with a mixture of strong clinical skills including Emergency Psychiatry, Consultation Liaison, Forensic Psychiatry, Telepsychiatry and Geriatric Psychiatry training in treatment of the elderly. I have training in EMR records thus very comfortable in working with computers. I served the difficult to treat patients in challenging environments in outpatient and inpatient settings

Leave a Comment

Scroll to Top