Clonazepam vs. Lorazepam

Instructor: Artem Cheprasov

Artem has a doctor of veterinary medicine degree.

This lesson compares and contrasts numerous different aspects of two drugs called clonazepam and lorazepam. You'll learn what they do, what adverse effects are more likely in one vs. the other, and much more.

Depressing the Brain

Believe it or not, sometimes we want to depress the brain in medicine. No, we don't try and make the person feel depressed. We try to depress, or 'calm down', excessive activity in the brain that may actually be causing any number of disorders. Two drugs used to that end include clonazepam and lorazepam. Let's compare and contrast them in this lesson.

Brand Names and Indications

Clonazepam is the generic term for Klonopin while lorazepam is the generic name for Ativan.


Both of these medications are used to manage seizures. But not just any seizures. Clonazepam is most commonly used to manage myoclonic, absence (petit mal), and akinetic seizures. It can also be used to treat Lennox-Gastaut syndrome, a type of severe epilepsy that begins in early childhood. Lorazepam is used to treat status epilepticus, which is a kind of severe and prolonged seizure.

In addition to managing one of the various types of seizures or seizure disorders, both medications have other indications (intended uses). Clonazepam can help manage panic disorder while lorazepam can also be used to help treat anxiety and it can also be used as part of anesthesia premedication. In other words, it can be given to someone prior to having surgery in order to relieve their anxiety or to produce sedation.

Dosage Forms & Pharmacology

Clonazepam can be given as a standard oral tablet or as a disintegrating oral tablet. On the other hand, lorazepam comes as an injectable solution, and oral concentrate, as well as in tablet form.

Both drugs are known as benzodiazepines, and they both work to depress nerve transmission in the brain, thereby preventing or minimizing the over-excitation of our nerve cells. Because they both work to stop or prevent seizures, they are also categorized as anticonvulsants.

Both drugs are rapidly absorbed in their various dosage forms. Clonazepam takes about 1-4 hours to peak in the blood. Lorazepam takes about 2 hours to peak when given orally. Both medications are excreted in urine.

Warnings & Adverse Effects


Neither drug should be given with opioids if such a combination is avoidable. This is because the simultaneous use of these medications and opioids can lead to profound sedation and respiratory depression. Coma and death are possible as well.

Neither medication should be given to a person with a known hypersensitivity (allergy) to the drug or any other ingredient in the medication's formulation. Clonazepam shouldn't be given to people with significant liver disease or acute narrow-angle glaucoma, the latter being a situation where a person experiences a sudden and/or severe increase in the pressure within their eye.

Lorazepam shouldn't be given to people with acute narrow-angle glaucoma either, nor to people with sleep apnea, severe respiratory depression, or to premature infants (with respect to the injectable form of lorazepam).

Adverse Effects & Pregnancy

Adverse Effects

These medications, owing to their similar pharmacology and indications, share many of the same adverse effects. However, such effects don't always occur with the same frequency. For example:

To unlock this lesson you must be a Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use

Become a member and start learning now.
Become a Member  Back
What teachers are saying about
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create an account