Diazepam’s Mechanism of Action: How This Benzodiazepine Works

Diazepam (Valium) belongs to a class of medications called benzodiazepines. It’s FDA approved to treat anxiety, muscle spasms and spasticity, and alcohol withdrawal symptoms. It can also treat seizures.

Diazepam works in a unique way to treat this wide range of health conditions. Below, we’ll discuss diazepam’s mechanism of action and other key information, such as how long it takes to work and how to know if diazepam is working.

What is diazepam?

Diazepam (valium) is a benzodiazepine medication. It’s available in several forms, including:

• Oral tablet (Valium)

• Oral liquid (Diazepam Intensol)

• Buccal film (Libervant)

• Rectal gel (Diastat, Diastat Acudial)

• Nasal spray (Valtoco)

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It’s also available as an intramuscular or intravenous injection that’s used in a healthcare setting.

The different forms of diazepam aren’t all FDA approved for the same reasons. But each form is approved for at least one of the following conditions:

• Seizures

• Anxiety

• Muscle spasms and spasticity

• Alcohol withdrawal symptoms

Like all benzodiazepines, diazepam is classified as a controlled substance. This means it has a risk for dependence and misuse, which can lead to a substance use disorder. It also has restrictions on how it may be prescribed, dispensed, and refilled.

What is diazepam’s mechanism of action?

Diazepam works by binding (attaching) to gamma-aminobutyric acid (GABA) receptors (binding sites). GABA is a calming chemical that your body naturally produces. It works by slowing down or stopping your nerve cells from communicating.

Diazepam does not directly increase GABA levels. Instead, it attaches to GABA receptors and changes their configuration to make it easier for GABA to attach. This boosts GABA’s activity, causing a calming effect throughout the body.

EXPERT PICKS: WHAT TO READ NEXT

• What are the most commonly used anxiety medications? Antidepressants are typically first-choice medications for anxiety. But benzodiazepines like diazepam may be a good option in some cases.

• What diazepam side effects should you watch for? Diazepam can cause drowsiness, dizziness, and more. It also has serious risks, such as misuse and overdose.

• What medications and substances should you avoid with diazepam? Don’t combine alcohol, opioids, and sleep aids with diazepam. These combinations can lead to serious drug interactions.

Diazepam’s effects on GABA make it useful for treating a variety of health conditions. Here’s a rundown on how diazepam helps different conditions.

Anxiety

As mentioned, GABA has a calming effect on the brain and body. So by increasing GABA activity, diazepam can help ease anxiety. Diazepam can also help manage some of the physical signs and symptoms of anxiety, such as sweating, trouble sleeping, and restlessness.

Alcohol withdrawal symptoms

Long-term alcohol use triggers changes in the brain, including an imbalance of chemicals. Your brain tries to maintain its normal function by decreasing GABA levels and increasing glutamate (the “excitatory” chemical).

But when you stop drinking, your brain becomes hyperactive due to the high glutamate and low GABA levels. This causes alcohol withdrawal symptoms, including fast heart rate, tremors, sweating, and, more seriously, seizures and hallucinations.

Since diazepam works by increasing GABA activity, it calms the brain and body. This relieves certain symptoms of alcohol withdrawal, including anxiety and seizures.

Muscle spasms

Your muscles tighten (contract) and relax based on messages they receive from the brain. This is usually an automatic process that you don’t have to think about. But if this brain-muscle connection is disrupted, you can have painful muscle spasms.

By acting on GABA receptors in the brain and spinal cord, diazepam blocks brain signals that tell muscles to contract unnecessarily. This relaxes your muscles and relieves spasms.

Seizures

Seizures are caused by abnormal signals in the brain. By affecting GABA receptors in certain parts of the brain, diazepam helps block this abnormal brain signaling, stopping episodes of seizures.

Does diazepam start working immediately?

Diazepam typically kicks in quickly. And this is helpful in many cases. For example, the best seizure medication is one that stops seizures as fast as possible.

Oral forms of diazepam work within about 15 to 60 minutes. But it may take a little longer for the medication to reach its full effect.

Diazepam can last several days in the body. Still, it's often taken several times a day. This is because its therapeutic effects don’t last as long as it stays in your blood. So if your prescriber recommends multiple doses a day, it’s to make sure diazepam levels are maintained in your body at all times.

How do you know if diazepam is working?

You’ll know diazepam is working if your symptoms improve. For example, if you’re taking diazepam for anxiety, you should feel calmer soon after taking it. If you’re taking it for muscle spasms, your muscles should feel more relaxed after taking it. 

If you don’t feel diazepam is working for you, let your prescriber know. They may want to adjust your dose or recommend a different medication.

Diazepam’s effects on GABA can also lead to side effects. Examples include drowsiness, dizziness, and trouble with coordination. That’s why it’s important to avoid activities that require alertness, such as driving, when you first start taking diazepam. Once you see how it affects you, talk with your prescriber to determine if it’s safe to resume these activities.

Are there alternatives to diazepam?

Although diazepam can effectively treat many conditions, it’s not often a first-choice medication. 

This is because it has some serious risks, especially if you take it long term. Its use can lead to misuse, dependence, and overdose. It can also cause drowsiness and dizziness, making falls, injuries, and accidents more likely. Older adults are more at risk of having permanent injury from falls.

Below, we’ll cover possible alternatives to diazepam. We’ll also discuss situations where it is considered a first-choice medication option.

Anxiety

Antidepressants are typically first-choice medications to treat anxiety. Even though not all antidepressants are FDA approved for anxiety, they are commonly used off-label for this reason. Examples include:

• Selective serotonin reuptake inhibitors (SSRIs), including sertraline (Zoloft) and escitalopram (Lexapro)

• Serotonin norepinephrine reuptake inhibitors (SNRIs), including duloxetine (Cymbalta) and venlafaxine (Effexor XR)

Unlike diazepam, SSRIs and SNRIs aren’t controlled substances and don’t cause misuse. But it can take weeks to months before you notice their full effects. So in some cases, your prescriber may recommend taking diazepam while you wait for your SSRI or SNRI to start working.

Alcohol withdrawal

Benzodiazepines are first-choice medications for alcohol withdrawal symptoms. When comparing diazepam to other benzodiazepines, it’s a good choice for alcohol withdrawal because it works quickly and lasts a long time. This lowers the risk for alcohol withdrawal symptoms returning.

However, in some cases, other benzodiazepines may be a better option. For example, if you have existing liver problems, lorazepam (Ativan) may be a better choice. It doesn’t rely as heavily on the liver for metabolism.

Muscle spasms

Benzodiazepines like diazepam aren’t typically first-choice medications for short-term muscle spasms. But diazepam may be an option if other medications, such as muscle relaxers, don’t work.

Seizures

Diazepam and other benzodiazepines aren’t first-choice medications for managing seizure disorder (epilepsy). Other seizure medications are often considered a better option.

However, benzodiazepines, including diazepam, are considered first-choice treatments for status epilepticus. This is when someone has a long-lasting seizure or multiple seizures back to back. Other benzodiazepines, such as lorazepam or midazolam, are also first-choice medications for status epilepticus. 

The best option for you depends on if you’re being treated in a hospital and other factors.

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Written by:

Alex Brewer, PharmD, MBA

Alex Brewer, PharmD, MBA, is a licensed pharmacist specializing in chronic disease and health and wellness. Upon completing his residency, he worked in the managed care field, conducting medication therapy management and adherence counseling sessions with Medicaid, Medicare, and private insurance patients, before transitioning to a career in medical writing.

Edited by:

Amy B. Gragnolati, PharmD, BCPS

Amy Gragnolati, PharmD, BCPS, is a pharmacy editor for GoodRx. Amy currently holds her pharmacist license in Georgia and California.

Reviewed by:

Patricia Pinto-Garcia, MD, MPH

Patricia Pinto-Garcia, MD, MPH, is a medical editor at GoodRx. She is a licensed, board-certified pediatrician with more than a decade of experience in academic medicine.

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