Lorazepam (Ativan)

Naomi Carr
Author: Naomi Carr Medical Reviewer: Tayler Hackett Last updated:

Lorazepam is a benzodiazepine that is primarily used to treat anxiety disorders and recurrent or enduring epileptic seizures. It is important to use this medication exactly as prescribed and to consult with your doctor prior to starting any other medications (prescribed or over the counter) while taking lorazepam, as adverse effects can occur.

Which brands is lorazepam usually prescribed as?

  • Ativan
  • Lorazepam Intensol

What is lorazepam prescribed for?

Lorazepam is mostly prescribed for the treatment of severe anxiety. It can also be prescribed for frequently recurring or enduring epileptic seizures, known as status epilepticus, for insomnia, or as an anesthetic premedication [1].

These are the FDA approved uses for lorazepam, but it can also be prescribed for other reasons, including the treatment of drug or alcohol withdrawal symptoms and to help alleviate nausea and vomiting in chemotherapy patients [2][3]. When lorazepam is prescribed for these reasons, this is known as ‘off-label’ use.

Lorazepam is not approved by the Food & Drug Administration (FDA) for use by children under 12 years old, as they may be more likely to experience dangerous side effects [4].

How does lorazepam work?

Lorazepam enhances a naturally occurring neurotransmitter in the brain called GABA, which helps calm the central nervous system and reduces symptoms of anxiety. As it can help regulate sleep and induce feelings of relaxation and anxiety, it can be used to treat various disorders and symptoms [5].

How is lorazepam usually taken?

Lorazepam comes in 0.5mg, 1mg, and 2mg tablets, which are swallowed whole; in liquid form, which is diluted in water or a soft drink or swallowed with food; or as an injection, which is administered intramuscularly (into a muscle) or intravenously (into a vein).

Depending on the condition that is being treated, you may receive a daily prescription of between 1-10mg, prescribed at either specified times or to take as it is required (PRN). Never take more than your doctor has prescribed for you.

  • For the treatment of anxiety, the dose is based on your total daily dose. You might have this prescribed as once a day, or 2-3 times a day in equally divided doses. Single doses range from 1-4mg, which will be decided by your doctor.
  • For the treatment of insomnia, you may be prescribed one dose of 1-2mg, to be taken orally, around 20-30 minutes before you go to bed.
  • If lorazepam is being used as a premedication for surgery, or as a treatment for seizures, it will likely be administered as an injection, which will be done by a healthcare professional.

Your prescription will depend on the severity of your condition, your age, and your weight/size, as these will all impact the effectiveness of the medication.

It is important you take your medication exactly as prescribed, to prevent adverse effects. If you are taking lorazepam for anxiety and miss a dose, you can take it when you remember, as long as it is within three hours of the prescribed time. Otherwise, skip that dose and take your next dose at the specified time. If you miss a dose that has been prescribed for insomnia, skip the dose entirely until the following night. Never take double the amount you have been prescribed.

Your doctor will likely advise that this treatment only continues for a short period of time, to prevent you developing a physical or psychological dependence on the medication. They will then likely reduce your daily prescription slowly, to prevent you from experiencing withdrawal symptoms [1][6].

How long does lorazepam stay in your system?

When taken by mouth, lorazepam begins working in 20-30 minutes. When injected intravenously, it begins working within 1-3 minutes, and when injected intramuscularly, it will begin working in around 15 minutes.

You will continue feeling the effects for 6-8 hours and it will be entirely out of your system after 14 hours.

Withdrawal symptoms can last several months after stopping the medication if a physical dependency has occurred. You may be more likely to experience withdrawal symptoms if you have taken large doses for prolonged periods, or if the medication is misused or abused [1][2][4].

Lorazepam side effects

This anti-anxiety medication causes sedation, so it is advised that you do not drive while on this medication if you feel very sleepy or drowsy.

Common side effects of lorazepam include:

  • Sleepiness
  • Muscle weakness
  • Changes in appetite, increase or decrease
  • Changes in bowel movements: constipation or diarrhea may occur initially
  • Unsteadiness
  • Difficulty concentrating
  • Slurred speech

Serious side effects are less common but may occur. If you experience any of the following symptoms, or any persistent side effects that are becoming problematic, you should consult your doctor:

  • Slow, shallow breathing
  • Involuntary tremors or shaking
  • Shuffling walk
  • Yellowing of the skin or eyes
  • Heart palpitations or irregular heartbeat
  • Memory difficulties
  • Sleepwalking
  • Mood changes, such as depression, low mood, or thoughts of harming yourself
  • Hallucinations or delusions (thinking or seeing things that are not real)

In very rare cases, Lorazepam may trigger an allergic reaction. If you experience any of the following, you should call 911 or go to the emergency room immediately.

  • Skin reactions such as a rash or blisters
  • Swelling in or around the mouth,
  • Breathing difficulties such as wheezing or tightness in your chest or throat

Lorazepam precautions

Discuss with your doctor all your current and previous physical and mental health conditions, as this may impact your ability to take this medication safely.

Because of the side effects of lorazepam, tell your doctor if you have ever experienced breathing problems such as asthma or sleep apnea, liver or kidney problems, or glaucoma.

It is important to tell your doctor if you have ever had an alcohol or substance use disorder, as this medication can be addictive, so it may not be suitable for you.

Tell your doctor about all medications you are taking, or plan to take (including vitamins and dietary supplements), as they may cause adverse reactions.

Lorazepam can cause you to feel very sleepy, so it may not be safe to drive or use machinery while on this medication.

If you are pregnant or plan to get pregnant, you should discuss this with your doctor before taking lorazepam, as it can cause your baby to be born with withdrawal symptoms or physical defects [1][4]. It can still be taken while pregnant if the benefits outweigh the risks, and it is vital for your treatment.

Inform your doctor if you have any planned surgery, as lorazepam can impact the effects of anesthesia. 

Lorazepam interactions

Lorazepam causes a sedative effect, so it must not be used with any opiate medications, such as morphine, hydrocodone, or oxycodone, as there is an increased risk of severe breathing problems that may lead to coma or death [1][4].

If you are using any other sedating medications, such as certain antihistamines, tranquilizers, or muscle relaxants, there may be an increased risk of breathing problems or oversedation. If you are taking any of these medications, discuss this with your doctor prior to beginning lorazepam.

Certain mental health medications may interact with lorazepam, such as various antidepressants and antipsychotics. These may increase side effects, so always discuss with your doctor first to understand how to take these medications safely.

Alcohol and other substances can increase the risk of heart, liver, or kidney problems if used alongside lorazepam and so the use of this medication alongside alcohol or recreational drugs is strongly discouraged, as they may exacerbate side effects and even increase the risk of overdose.

Lorazepam storage

Always keep all medications out of reach of children.

Store lorazepam in its original packaging, in airtight containers, and at room temperature (never above 86 F).

If you need to dispose of medication that is out of date or no longer needed, contact a medical professional to ensure it is disposed of appropriately. Never flush medications down the toilet or put them in the bin, as this can create unnecessary risks.

What to do if you overdose on lorazepam

If you overdose on lorazepam, call a medical professional or Poison Control on 1-800-222-1222, or if emergency medical attention is required, call 911.

A severe overdose can cause breathing problems, collapse, confusion, loss of consciousness, coma, or even death. There is a medication that can reverse lorazepam effects, although this must be given by a professional, who will decide if it is necessary [1].

FAQs about lorazepam

Can you drink alcohol while on lorazepam?

It is not safe to drink alcohol while on lorazepam. Alcohol can increase the sedative effect of lorazepam, which can result in breathing difficulties or an inability to awaken. It may also increase the risk of liver problems.

Is lorazepam addictive?

Lorazepam can be addictive, so it is usually prescribed as a short-term treatment option – typically under four months – and must be taken as prescribed. As such, suddenly stopping can cause withdrawal symptoms, so your doctor may slowly reduce your dose of lorazepam before stopping your prescription to prevent this. You should never suddenly stop taking prescribed medication without medical advice and supervision.

Lorazepam vs clonazepam: what’s the difference?

The two medications are very similar in cost, effectiveness, onset time, and side effects.

Both lorazepam (Ativan) and clonazepam (Klonopin) are benzodiazepine medications, so have similar effects on the brain and body. Clonazepam may also be prescribed for the treatment of anxiety-related symptoms or epileptic seizures, although they are FDA approved for slightly different uses [6].

  1. The College of Psychiatric and Neurologic Pharmacists (CPNP) and the National Alliance on Mental Illness (NAMI). (2021). Lorazepam (Ativan). NAMI. Retrieved from https://www.nami.org/About-Mental-Illness/Treatments/Mental-Health-Medications/Types-of-Medication/Lorazepam-(Ativan)
  2. Ativan (Lorazepam). (2012). Journal of Addictions Nursing23(2), 141–142. Retrieved from https://doi.org/10.3109/10884602.2012.669122
  3. Heavner, J. J., Akgün, K. M., Heavner, M. S., Eng, C. C., Drew, M., Jackson, P., Pritchard, D., IX, & Honiden, S. (2018). Implementation of an ICU-Specific Alcohol Withdrawal Syndrome Management Protocol Reduces the Need for Mechanical Ventilation. Pharmacotherapy38(7), 701–713. Retrieved from https://doi.org/10.1002/phar.2127
  4. Bausch Health. (2020). Ativan (Lorazepam) Tablets. Access Data FDA. Retrieved from https://www.accessdata.fda.gov/drugsatfda_docs/label/2021/017794s048lbl.pdf
  5. Ghiasi, N., Bhansali, R.K., & Marwaha, R. (January 2022). Lorazepam. Treasure Island, FL: StatPearls Publishing. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK532890/
  6. Ativan (Lorazepam). (2021). Medical News Today. Retrieved from https://www.medicalnewstoday.com/articles/326015
  7. Sirven, J.I., Obsorne Shafer, P., & Schachter, S. (August 2013). Status Epilepticus. Epilepsy Foundation. Retrieved from https://www.epilepsy.com/complications-risks/emergencies/status-epilepticus
  8. American Society of Health-System Pharmacists, Inc. (n.d.). Lorazepam. MedlinePlus. Retrieved from https://medlineplus.gov/druginfo/meds/a682053.html
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Naomi Carr
Author Naomi Carr Writer

Naomi Carr is a writer with a background in English Literature from Oxford Brookes University.

Published: Nov 22nd 2022, Last edited: Feb 21st 2024

Tayler Hackett
Medical Reviewer Tayler Hackett BSc, PGCert

Talyer Hackett is a medical writer and researcher with 10+ years of experience, holding B.A. in Psychology from the University of Liverpool.

Content reviewed by a medical professional. Last reviewed: Nov 23rd 2022