Klonopin (Clonazepam) Vs. Ativan (Lorazepam) | Differences & Similarities

Klonopin and Ativan are both benzodiazepines, but Klonopin is a long-acting benzodiazepine and Ativan is an intermediate-acting benzodiazepine.

Klonopin and Ativan are the brand names for clonazepam and lorazepam, respectively. These two drugs share a number of similarities including the drug class they are in, how they work, and the side effects they have.

But despite those similarities, the differences between the two drugs include active ingredient, half-life, and how long they are effective.

Differences Between Klonopin & Ativan

Klonopin and Ativan have a few differences and those differences are one of the reasons your healthcare provider may prescribe one over the other.

Active Ingredient

The main difference between Klonopin and Ativan is their active ingredient. Klonopin’s active ingredient is clonazepam while Ativan’s active ingredient is lorazepam.


Another key difference between the two prescription drugs is their half-life. A half-life is the time it takes for half a dose of a drug to exit your system.

For clonazepam, the half-life is 30-40 hours while lorazepam has a half-life of about 12 hours. This means that clonazepam will likely stay in your body longer than lorazepam

Length Of Effect

While Klonopin and Ativan are both benzodiazepines (benzos), they differ in how long the effects last. Klonopin is a long-acting benzodiazepine which means its effects last for a longer period of time than an intermediate-acting benzodiazepine like Ativan.

Similarities Between Klonopin & Ativan

Despite those differences, the two drugs have quite a few similarities including approved uses and drug class.

Medical Uses

One of the major similarities between Klonopin and Ativan is what they treat. They both are typically used for the treatment of mental health conditions like anxiety disorders and panic disorders, seizure disorders like epilepsy, and alcohol withdrawal.

Both can also be used for insomnia but Ativan is the only one approved by the FDA for that specific use.

Drug Class

As noted above, both Klonopin and Ativan are benzodiazepines. They are also both anticonvulsants and anxiolytics (anti-anxiety medications).

Benzodiazepines work by binding to the gamma-aminobutyric acid (GABA) receptors in the brain. This action increases the effects of the neurotransmitter GABA in the central nervous system (CNS).

GABA slows down or depresses the CNS and in turn, can control seizures and ease the symptoms of anxiety and panic attacks. Other drugs in this class include Valium (diazepam) and Xanax (alprazolam).

Controlled Substance Schedule

Klonopin and Ativan are also both schedule IV controlled substances according to the FDA and DEA. This means that they have a relatively low potential for abuse but can still lead to dependence and addiction. This is why they are typically prescribed for short-term treatment.

Side Effects

Clonazepam and lorazepam also share quite a few of the same side effects.

The most common side effects you may experience if you take either of these medications include:

  • drowsiness
  • dizziness
  • tiredness
  • muscle weakness
  • headache
  • blurred vision
  • insomnia
  • unsteadiness
  • memory problems
  • difficulty concentrating
  • nausea and vomiting
  • constipation
  • changes in appetite

Drug Interactions

There are also several medications and substances that shouldn’t be mixed with Ativan or Klonopin. The combination could lead to serious adverse effects that can be life-threatening.

The substances that don’t mix well with Ativan or Klonopin include:

  • alcohol
  • cold or allergy medicine
  • opioid painkillers
  • sleeping pills
  • muscle relaxers
  • other anticonvulsants
  • other anti-anxiety medications
  • barbiturates
  • MAO inhibitors
  • antidepressants
  • hypnotics/sedatives
  • antihistamines

Clonazepam and lorazepam are also not recommended for anyone who is pregnant or breastfeeding. Both prescription drugs can transfer into breast milk and could lead to sedation or excessive drowsiness in an infant who is breastfeeding.

Worsened Medical Conditions

Besides those who are pregnant or breastfeeding, there are also several medical conditions that Klonopin and Ativan can make worse.

If you have any of the following conditions, these drugs may not be for you:

  • glaucoma
  • lung disease
  • liver disease
  • kidney disease
  • heart disease

Withdrawal Symptoms

If you abuse either Klonopin or Ativan over a period of time, your body may become dependent on the drug. If that happens and you try to quit using either drug, unpleasant withdrawal symptoms are likely to occur.

If you or a loved one is struggling with benzodiazepine abuse or another form of substance use disorder, please contact us today.

Written by
Northeast Addition Editorial Team

©2024 Northeast Addition Center | All Rights Reserved

This page does not provide medical advice.

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