Klonopin (clonazepam) vs. Xanax (alprazolam)

  • Medical Reviewer: Melissa Conrad Stöppler, MD
    Melissa Conrad Stöppler, MD

    Melissa Conrad Stöppler, MD

    Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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Klonopin (clonazepam) vs. Xanax (alprazolam) review

  • Klonopin (clonazepam) and Xanax (alprazolam) belong to a class of drugs called benzodiazepines.
  • Benzodiazepines are medications that cause drowsiness (sedation) and inhibition of nerve signals within the brain (central nervous system or CNS). They also are used for sedation during surgery.
  • Both Klonopin and Xanax are prescribed to treat anxiety. Symptoms of anxiety include:
    • Headaches
    • Sleep problems
    • Becoming tired easily
    • Irritability
    • Muscle tension
    • Restlessness or feeling edgy
    • Trouble concentrating
  • Klonopin also is prescribed to treat certain types of seizures and Lennox-Gastaut syndrome.
  • Since both Klonopin and Xanax are benzodiazepines, they can cause physical dependence (addiction). Withdrawal symptoms from suddenly stopping taking these medications can include insomnia, headaches, nausea, vomiting, sweating, tremors, and seizures.
  • Examples of common side effects of benzodiazepines like Klonopin and Xanax include
  • Klonopin and Xanax interact with alcohol, barbiturates, narcotics, and other drugs or substances that slow the brain's processes. Xanax also interacts with several other drugs.
  • Both Klonopin and Xanax are not recommended during pregnancy due to the risk of fetal abnormalities. Both drugs also are secreted in breast milk and can affect nursing infants. Therefore they should not be used by women who are nursing.

What are Klonopin and Xanax?

What is Klonopin (clonazepam)?

  • Klonopin (clonazepam) is an anti-anxiety medication in the benzodiazepine family, the same family that includes, for example:
  • Klonopin and other benzodiazepines act by enhancing the effects of gamma-aminobutyric acid (GABA) in the brain. GABA is a neurotransmitter (a chemical that nerve cells use to communicate with each other) that inhibits brain activity. It is believed that excessive activity in the brain may lead to anxiety or other psychiatric disorders. Clonazepam is primarily used for treating panic disorder and preventing certain types of seizures.
  • The FDA approved clonazepam in June 1975.

What is Xanax (alprazolam)?

  • Xanax (alprazolam) is an anti-anxiety medication in the benzodiazepine family, the same family that includes, for example:
    • diazepam (Valium)
    • clonazepam (Klonopin)
    • lorazepam (Ativan)
    • flurazepam (Dalmane)
  • Xanax and other benzodiazepines act by enhancing the effects of gamma-aminobutyric acid (GABA) in the brain. GABA is a neurotransmitter (a chemical that nerve cells use to communicate with each other) that inhibits activity in the brain. It is believed that excessive activity in the brain may cause anxiety or other psychiatric disorders.
  • The FDA approved Xanax in October 1981.
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What generic names are available for Klonopin and Xanax?

  • Clonazepam is the brand name for Klonopin available for in the US.
  • Alprazolam is the brand name for Xanax available in the US.

What are the uses for Klonopin (clonazepam) vs. Xanax (alprazolam)?

Klonopin (clonazepam) uses

Klonopin (clonazepam) is used for:

  • The treatment of panic disorder
  • Certain types of seizures, specifically petit mal seizures, akinetic seizures, and myoclonus, as well as Lennox-Gastaut syndrome. Klonopin maybe used alone or together with other medications for these seizure disorders.
  • The short-term relief of symptoms of anxiety.

Xanax (alprazolam) uses

Xanax (alprazolam) is used for the treatment of anxiety disorders and panic attacks. Anxiety disorders are characterized by:

Panic attacks occur either unexpectedly or in certain situations (for example, driving), and can require higher dosages of Xanax.

What are the side effects of Klonopin (clonazepam) vs. Xanax (alprazolam)?

Klonopin (clonazepam) side effects

The most common side effects associated with Klonopin (clonazepam) are sedation, which is reported in approximately half of patients. Dizziness is reported in one-third of patients.

Other common side effects include:

Other serious side effects of Klonopin include:

Other serious adverse reactions:

  • Antiepileptic medications have been associated with an increased risk of suicidal thinking and behavior. Anyone considering the use of antiepileptic drugs must balance this risk of suicide with the clinical need for the antiepileptic drug. Patients who begin antiepileptic therapy should be closely observed for clinical worsening, suicidal thoughts or unusual changes in behavior.

Xanax (alprazolam) side effects

The most common side effects of Xanax taken at lower doses are:

Other side effects include:

  • Fatigue
  • Memory problems
  • Speech problems
  • Constipation
  • Changes in weight
  • Addiction (dependency)

What are the withdrawal symptoms of Klonopin (clonazepam) vs. Xanax (alprazolam)?

Klonopin (clonazepam) withdrawal symptoms

  • Like all benzodiazepines, Klonopin can cause physical dependence.
  • Suddenly stopping therapy after a few months of daily therapy may be associated with a feeling of loss of self-worth, agitation, and insomnia.
  • If Klonopin is taken continuously for longer than a few months, stopping therapy suddenly may produce:
    • Seizures
    • Tremors
    • Muscle cramping
    • Vomiting
    • Sweating
  • Therefore, discontinuation usually is accomplished by reducing the dose gradually.

Xanax (alprazolam) withdrawal symptoms

Addiction is more likely to occur at high doses given over prolonged periods of time. Abrupt discontinuation of Xanax after prolonged use can lead to symptoms of withdrawal such as:

  • Insomnia
  • Headaches
  • Nausea,
  • Vomiting
  • Lightheadedness
  • Sweating
  • Anxiety
  • Fatigue

Seizures can occur in more severe cases of withdrawal. Consequently, patients on Xanax for extended periods of time should slowly taper the medication under a doctor's supervision rather than abruptly stopping the medication.

How should Klonopin (clonazepam) vs. Xanax (alprazolam) be taken (dosage)?

Klonopin (clonazepam) dosage

The dose of Klonopin (clonazepam) is tailored to the patient's needs.

  • For seizures in adults the initial dose is 1.5 mg daily in 3 divided doses.
  • Dosage may be increased by 0.5 to 1 mg daily every 3 days until seizures are controlled or side effects preclude further increases in dose.
  • The maximum dose is 20 mg daily. The initial dose for panic disorders is 0.25 mg twice daily.
  • The dose may be increased to the target dose of 1 mg daily after 3 days.

Xanax (alprazolam) dosage

Xanax may be taken with or without food.

Which drugs interact with Klonopin (clonazepam) vs. Xanax (alprazolam)?

Klonopin (clonazepam) drug interactions

  • Klonopin (clonazepam), like all other benzodiazepines, accentuates the effects of other drugs that slow the brain's processes, such as alcohol, barbiturates, and narcotics and leads to increased sedation.

Xanax (alprazolam) drug interactions

Xanax (alprazolam) interacts with

These increase concentrations in the blood of Xanax and therefore may increase the side effects of Xanax. Xanax interacts with alcohol and medications (for example, barbiturates, and narcotics) that suppress activity in the brain by suppressing activity more and causing sedation.

Carbamazepine (Tegretol, Tegretol XR, Equetro, Carbatrol) and rifampin reduce the effect of Xanax by increasing metabolism and elimination of Xanax in the liver.

Are Klonopin and Xanax safe to take during pregnancy or while breastfeeding?

Klonopin (clonazepam) pregnancy and breastfeeding safety

  • Klonopin (clonazepam) and other benzodiazepines have been associated with fetal damage, including congenital malformations, when taken by pregnant women in their first trimester. Klonopin is best avoided in the first trimester and probably throughout pregnancy.
  • Benzodiazepines are secreted in breast milk. Mothers who are breastfeeding should not take Klonopin.

Xanax (alprazolam) pregnancy and breastfeeding safety

  • Benzodiazepines, such as Xanax, can cause fetal abnormalities and should not be used in pregnancy.
  • Xanax is excreted in breast milk and can affect nursing infants. Therefore, it should not be used by women who are nursing.

REFERENCES:

FDA Prescribing Information. "XANAX® alprazolam tablets, USP." Revised March 2011.
<http://www.accessdata.fda.gov/drugsatfda_docs/label/2011/018276s044,021434s006lbl.pdf>

FDA Prescribing Information. "KLONOPIN® Tablets (clonazepam); KLONOPIN® WAFERS (clonazepam orally disintegrating tablets)." PI Revised: Apr 2009.
<http://www.accessdata.fda.gov/drugsatfda_docs/label/2009/017533s045,020813s005lbl.pdf>

United States Drug Enforcement Administration. "Drug Schedules."
<https://www.dea.gov/druginfo/ds.shtml>

United States Drug Enforcement Administration. "Drug Fact Sheet. Benzodiazepines."
<https://www.dea.gov/druginfo/drug_data_sheets/Benzodiazepines.pdf>

Last Editorial Review: 12/12/2016

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Reviewed on 12/12/2016
References
REFERENCES:

FDA Prescribing Information. "XANAX® alprazolam tablets, USP." Revised March 2011.
<http://www.accessdata.fda.gov/drugsatfda_docs/label/2011/018276s044,021434s006lbl.pdf>

FDA Prescribing Information. "KLONOPIN® Tablets (clonazepam); KLONOPIN® WAFERS (clonazepam orally disintegrating tablets)." PI Revised: Apr 2009.
<http://www.accessdata.fda.gov/drugsatfda_docs/label/2009/017533s045,020813s005lbl.pdf>

United States Drug Enforcement Administration. "Drug Schedules."
<https://www.dea.gov/druginfo/ds.shtml>

United States Drug Enforcement Administration. "Drug Fact Sheet. Benzodiazepines."
<https://www.dea.gov/druginfo/drug_data_sheets/Benzodiazepines.pdf>

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