Ativan (Lorazepam) side effects and drug information

Ativan, with a generic name lorazepam, belongs to a group of medications called benzodiazepines. It is a prescription drug that works as a treatment for symptoms of anxiety, insomnia, status epilepticus, which is a type of severe seizure and also used as anesthesia, so it is given preceding surgery.


ChEMBL Id 580
ChemSpider ID 3821
Molar mass 321.2 g/mol
CAS ID 846-49-1
Boiling point 533.8 °C


This tranquillizing drug is also known for its other term, which is sedative-hypnotic or anxiolytic medication and is available in two forms which are: tablets and solution for intravenous injection.

Since patients have an alternative to buying its generic version, which is lorazepam, this medication can be purchased more affordably. However, there are instances when the generic version and the drug with a brand name may not have the same strengths and may be available in different forms.

Side Effects

Consult your doctor before taking this medication so you can be aware of its potential side effects as they may vary from mild to severe. Discussing with your doctor about its possible reactions to your body will also guide you on how to deal with them in case the symptoms show up.

More Common Side Effects

Some of the known common reactions of Ativan are:

  • Weakness
  • Drowsiness
  • Dizziness

There are also some cases when people experience the following side effects, though less frequent:

  • Headache
  • Lack of coordination
  • Confusion
  • Restlessness
  • Depression
  • Fatigue

For those who get the injection, the common side effects are redness and pain, cause weakness where the medicine was injected.

Several of these reactions are expected to be relieved after a few days or some weeks, but if they become more severe and continue to persist, inform your doctor.

Serious Side Effects

Though side effects from Ativan are not usually serious, it does not mean that they can’t happen. If they do, call your doctor immediately or call 911 if it is life-threatening.

Some possible serious side effects that can occur:

  • Slowed breathing
  • Respiratory failure (though rare)
  • Psychological and physical dependence
  • Vomiting
  • Nausea
  • Anxiety
  • Depression
  • Muscle weakness
  • Nightmares
  • Body aches
  • Sweating
  • Severe rash
  • Rapid heartbeat
  • Trouble breathing or swallowing
  • Suicidal thoughts

Side Effects in Children

This medication is not meant to be used for children 12 years old and below as it has not been approved by the Food and Drug Administration (FDA) for use in children below the age of 12.

Children have a higher risk of experiencing side effects than adults when using Ativan.

Side Effects in Seniors

Use of Ativan for seniors must be done in a very cautious manner, or if possible, avoid this treatment on them as it may cause drowsiness or dizziness or dizzy and may lead to a more serious risk of falling and result in further injuries like bone fractures.

Long Term Side Effects

This drug should not be used for a prolonged period as it is habit-forming and can be addictive. FDA approved its use for a maximum of 4 months.  

Extended use of this drug may cause some severe side effects such as:

  • Drug dependence
  • Rebound effects
  • Impair your ability to drive or operate an equipment
  • Nausea
  • Headache
  • Slow breathing and in very rare cases, may lead to respiratory failure
  • Weight change which can either be weight loss or weight gain
  • Memory loss
  • Constipation
  • Vertigo
  • Hallucinations

As for the instance of slow breathing, the bigger chance of this happening is for those who are:

  • Older people
  • Taking other drugs that affect breathing like opioids
  • Severely ill
  • Receiving high doses of Ativan
  • Have breathing disorder like sleep apnea or chronic pulmonary disorder

For memory loss, this side effect should go away after you stop taking this medication.

Indication and dosage

The following information is the average doses for the use of Ativan in different types of situations.

Usual Adult Dose of Ativan for Anxiety

The recommended dosage that can be given to an adult for anxiety treatment is from 1 to 10mg per day, where the initial dosage should be 2 to 3mg for 2-3 times a day.  

For the maintenance dosage for this treatment, it is 1 to 2mg for 2 to 3 times a day and should be administered orally. For the parenteral method, the IV should only be up to 2mg in total or 0.044mg/kg, whichever is smaller.

Should the dosage needs to be increased, the process must be gradual so as not to have an adverse effect, and the evening dose should be increased first before the daytime dose.

Usual Adult Dose for Light Anesthesia

For the IM administration of Ativan, the allowed dosage is from 0.05mg/kg up to only 4mg maximum. And to achieve its full effect using IM, the drug should be administered for a minimum of 2 hours preceding the operative procedure.

For IV use, the recommended dosage is a total of 2mg or 0.044mg/kg, whichever is smaller. If a larger dose is necessary, the allowed dosage would be 0.05mg/kg and only up to 4mg maximum. For its full effect, IV should be administered 15 to 20 minutes before the surgery.

For patients over 50 years old, the dosage should not be exceeded.

When using this drug, doses of other injectable CNS depressant medications must be lessened; and narcotic analgesics should be given at their usual preoperative time.

Usual Adult Dose for Status Epilepticus

The appropriate dosage for this treatment in adults is 0.1mg/kg IV for up to a maximum of 4mg per dose, which can be repeated for around 5 to 10 minutes. The maximum allowed dosage is 8mg.

When administering this procedure, the vital signs need to be monitored, and an unobstructed airway must be maintained. It is also necessary that artificial ventilation equipment is available.

In case an IV port is not present, the IM procedure may also be performed.

Usual Adult Dose for Insomnia

To treat insomnia in an adult, the recommended dosage is 2 to 4mg and should be taken at bedtime. If there is a need for the dosage to be increased, it should be gradually to avoid any adverse reaction.

Usual Geriatric Dose for Anxiety

The dosage for seniors or debilitated patients is 1 to 2mg a day and must be administered in divided doses. Medication should be given orally.

If the dosage needs to be increased, the increase must be gradual to avoid side effects.

Usual Pediatric Dose for Anxiety

The everyday dose may range from 1 to 10mg a day, but the initial dosage is 2 to 3mg for 2 to 3 times a day. The administration must be done orally.

For maintenance, the recommended dosage is 1 to 2mg for 2 to 3 times a day and should be given orally.

Dosage may be increased if necessary but should be done gradually, and the evening dosage should be increased before the daytime dose.

Usual Pediatric Dose for Insomnia

The recommended dose for patients 12 years old and up, is 2 to 4mg and should be orally administered at bedtime.

Drug Interaction

If you are taking any of these medications, inform your doctor:

  • Other benzodiazepines like Xanax, Librium, Klonopin, Tranxene, and Valium
  • Birth control pills
  • Barbiturates
  • Antipsychotics
  • Sleep medications
  • Narcotic drugs
  • Antidepressants
  • Anti-seizure drugs
  • Sedating allergy medicines including Benadryl
  • Anesthetics
  • Probenecid
  • Theophylline
  • Aminophylline
  • Scopolamine

Lorazepam and Alcohol

It is not safe to consume alcohol while taking lorazepam as this drug lowers your tolerance for alcohol and will cause drowsiness, confusion, and unsteadiness. Severe cases may also arise, such as breathing problems, coma, and even death.

Within 8 hours of getting lorazepam injection, use caution when getting out of bed and walking; and avoid driving or operating a piece of machinery for about 24 to 48 hours after dose of this drug.

Allergic Reaction: Serious allergic reactions are also experienced by some patients, such as severe rash, hives problems, swollen face, or throat or difficulty in breathing.

Inform your doctor if you have any allergies or if you are pregnant or breastfeeding before using this drug.

Dependence and Withdrawal: Prolonged use of this medication for agitation can be harmful as it tends to cause physical dependence on the drug.  

If this drug was abruptly discontinued, some withdrawal symptoms are:

To avoid these withdrawal symptoms, reduce the dosage gradually, and it should be under medical supervision.

  • Depression:

It is recommended that patients suffering from depression should be treated with an antidepressant treatment before starting using this medication as it can only worsen the condition.

  • Drowsiness:

Avoid driving or doing any activity that requires you to be alert when under this medication as it causes drowsiness.

  • Lung Disease:

Consult your doctor if you have this condition to know how this drug may affect your existing situation.

  • Pregnancy:

This medication may be harmful to an unborn child and may cause congenital disabilities, so this is not meant to be used when pregnant. Talk to your doctor if you become pregnant while on this treatment.

  • Breastfeeding:

Lorazepam quickly passes into the breastmilk and may affect your baby.

  • Children and Adolescents:

Effectiveness and safety of this medicine have not been established for patients 18 years old and below.

  • Seniors:

Older people may have a higher risk of experiencing side effects from this drug.

Clinical Pharmacology

According to studies on a normal population, a single high dosage of Ativan works as a tranquillizing agent on the CNS, but with no visible reaction on the respiratory and cardiovascular systems.

Ativan is easily absorbed with a bioavailability of 90%, with peak concentrations in plasma occurring about 2 hours after administration. It is noted that the peak plasma level from lorazepam from a 2mg dosage is around 20ng/ml

Medical Guide

To ensure safety in the usage of Ativan (Lorazepam), individuals should be aware that benzodiazepines may cause physical and psychological dependence, so it is advised to consult with your doctor before using this product, or before adjusting your dosage.