Lorazepam
How Does Lorazepam Work? All About Its Mechanism of Action
Lorazepam (Ativan, Lorazepam Intensol, Loreev XR) is a prescription medication that’s FDA approved to treat short-term anxiety. It’s part of a group of medications called benzodiazepines.
Lorazepam works by making a chemical called GABA (gamma-aminobutyric acid) more active. This has a calming effect on the body. Positive effects include muscle relaxation and anxiety relief. But it also causes side effects like drowsiness and dizziness.
Lorazepam is a controlled substance that can be habit forming. It has the ability to cause dependence, misuse, and overdose. So it’s not usually a first-choice option for anxiety.
Giulio Fornasar/iStock via Getty Images Plus Lorazepam is part of a group of medications called benzodiazepines. These medications are prescribed for a variety of reasons.
Lorazepam specifically is FDA approved for short-term treatment of anxiety. How does it work, and what sets it apart from other anxiety medications? Let’s take a closer look at lorazepam’s mechanism of action.
Lorazepam is a benzodiazepine medication. It’s approved to treat anxiety. But it’s meant to be used short term. Besides anxiety, lorazepam is sometimes prescribed for conditions it’s not FDA approved for (called “off-label” uses). For example, lorazepam may be prescribed to treat alcohol withdrawal, trouble sleeping, and panic disorder.
Lorazepam is a controlled substance. This means it has significant risks, including dependence and misuse. There are also restrictions around how lorazepam is prescribed and refilled. It’s available as four different products:
Immediate-release (IR) tablet (Ativan)
Oral liquid (Lorazepam Intensol)
Extended-release capsule (Loreev XR)
Intravenous or intramuscular injection (Ativan)
The IR tablet, oral liquid, and injection also come in generic forms.
Lorazepam works by increasing the effects of a chemical called GABA (gamma-aminobutyric acid). This is a naturally occurring chemical in the body that has a calming effect.
Lorazepam affects GABA by attaching to certain GABA binding sites (receptors). When lorazepam attaches to these receptors, it becomes easier for GABA to attach as well. Increasing GABA activity has many effects, both positive and negative. Examples include:
Muscle relaxation
Reduced anxiety
Seizure control
Drowsiness
Worsening coordination
Trouble remembering things
Lorazepam is broken down (metabolized) in the liver. But unlike many other benzodiazepines, lorazepam metabolism doesn’t involve liver proteins (enzymes). So lorazepam may be a better option for people who have liver issues.
When taken by mouth, lorazepam works relatively quickly. You may feel the maximum effect of lorazepam 1 to 2 hours after taking it. But relaxation and anxiety relief may be felt even sooner than that — within 30 minutes for some people.
Lorazepam is considered an intermediate-acting benzodiazepine. It’s not as short acting as some benzodiazepines, such as alprazolam (Xanax). But it’s not as long acting as others, such as diazepam (Valium).
A dose of lorazepam may last 3 to 4 days in the body. So it’s possible to feel drowsiness and problems with coordination for a while after you take it. Be careful completing activities that require alertness until you know how lorazepam affects you. This includes driving or operating other forms of heavy machinery.
Lorazepam has some differences from other anxiety medications, including:
How it works: Lorazepam works different from commonly prescribed anxiety medications, such as selective serotonin reuptake inhibitors (SSRIs) and serotonin and norepinephrine reuptake inhibitors (SNRIs). These medications affect brain chemicals like serotonin and norepinephrine. Lorazepam mostly affects the chemical GABA.
When it’s used: Lorazepam isn’t a first-choice option for anxiety. It’s effective at treating anxiety symptoms. But it has significant risks, including dependence, misuse, and overdose. So it’s not usually the first medication your healthcare provider will recommend for anxiety.
Risks: Many anxiety medications — such as SSRIs, SNRIs, and buspirone — aren’t habit-forming. But lorazepam can be, making it a less safe option for most people.
Frequency of doses: Lorazepam is usually taken multiple times a day. Some SSRIs and SNRIs need to be taken only once a day. But lorazepam is usually taken two to three times throughout the day.
Lorazepam (Ativan) is part of a group of medications called benzodiazepines. It’s FDA approved to treat anxiety. It has many off-label uses, too, including alcohol withdrawal and panic disorder.
Lorazepam works by making a chemical called GABA (gamma-aminobutyric acid) more active. This has a calming effect on the body, causing muscle relaxation and anxiety relief. But it can also cause drowsiness, trouble with coordination, and memory problems. More seriously, lorazepam can cause dependence, misuse, and overdose. So it’s not usually a first-choice medication for anxiety.
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