Lorazepam: What it Is and How it Works

Lorazepam is a short-acting benzodiazepine widely used for the treatment of anxiety. However, you should be aware of certain warnings about this drug.
Lorazepam: What it Is and How it Works

Last update: 06 October, 2021

Lorazepam is a drug from the group of benzodiazepines (BZD) used to combat anxiety and nervousness. Depending on the case, its consumption may be prescribed for certain periods of time (short-term treatment) or seasonally (long-term treatment).

Have you ever heard it mentioned or has it been prescribed for you? If so, it would be good for you to know a little more about its mechanism of action and its pharmacological actions, as well as its adverse reactions and its pharmacokinetics. Firstly, we need to know what we mean when we talk about anxiety.

What is anxiety?

As experts indicate, anxiety is a natural adaptive mechanism that, when it becomes too much and affects a person in various ways, can be considered a disorder. They also add that “anxiety disorders are, as a whole, the most common psychiatric illness.”

In other words, in normal situations, anxiety is a component of normal mental activity involved in defense mechanisms and can be linked to situations of stress. This situation becomes pathological when limits are exceeded, nullifying or hindering adaptation to the stressful situation.

In these cases, the feeling of anxiety can be described as a feeling of threat, of tense expectation about the future, and of an alteration of the psychosomatic balance in the absence of real danger.

When under the effects of anxiety, different feelings coexist in the patient such as apprehension, fear, or anguish in the face of something “threatening”, or a state of irritability and, together, these can cause various symptoms such as the following:

  • Fatigue
  • Insomnia
  • Headaches
  • Sweating
  • Palpitations
A man with a panic attack.

What’s an anxiolytic drug?

Drugs used to combat anxiety, such as lorazepam, are called anxiolytic drugs. These alleviate or suppress the anxiety syndrome without producing sedation or sleep. In small doses, they are usually only capable of producing anxiolysis.

However, as the dose is increased, in some cases, the effects of sedation, coma, and even death from intoxication may appear.

Mechanism of action of lorazepam

Lorazepam is a short-acting drug for the treatment of anxiety. To achieve its anxiolytic action, this drug has two complementary mechanisms.

It facilitates the transition from GABA

GABA is a neutral transmitter with the ability to inhibit or reduce neuronal activity. Therefore, the binding of lorazepam with the GABA receptor will produce a change in it that will result in a better binding with the neurotransmitter. By enhancing this binding, its inhibitory capacity is improved.

Binding of lorazepam to specific sites of the GABA-BZD receptor complex

This complex has several domains: α1, ß2, and γ2. It’s very important to achieve the correct selectivity of these receptors to separate the hypnotic action from the anxiolytic one. Specifically, for anxiolytic action, the subreceptor involved is BZ2 (ω2).

Pharmacological actions

Depending on the characteristics of the benzodiazepines, one or either of these actions can take place, or even both at the same time. Lorazepam has anxiolytic and anticonvulsant actions.

The anxiolytic action is characteristic of the BZ2 receptor, as we have mentioned before. By binding to this complex, it triggers actions that decrease anxiety and aggressiveness.

A woman who needs lorazepam.

Healthy people and people with anxiety

So, it’s important that we distinguish between healthy people taking lorazepam and patients with anxiety:

  • In healthy people, at therapeutic doses, the performance of physical or mental exercises isn’t altered. At higher doses, it can cause drowsiness, lethargy, ataxia, and muscle weakness. The main drawback is ”residual sleep”.
  • In patients with anxiety, lorazepam relieves both subjective tension and subjective symptoms. However, it isn’t very effective in situations of panic, phobias, and non-neurotic anxiety.

It can also have an effect on aggressiveness and memory, depress the cardiovascular and respiratory systems, and decrease the ability to speak and express oneself.

Lorazepam pharmacokinetics

This drug, like the other benzodiazepines, is well absorbed orally. In addition, it’s bound to a fairly high degree to plasma proteins. Therefore, care must be taken, as it can interact with other drugs that present these characteristics.

It’s also a very fat-soluble drug, a necessary characteristic to be able to cross the blood-brain barrier that protects the brain, and trigger its action at the central level.

It’s also a molecule that’s already oxidized. Therefore, in its metabolism, it will only undergo conjugation reactions. This is very useful in geriatric patients, as, at this age, the functionality of the liver is usually diminished, and by requiring fewer metabolization reactions, patients at this age will eliminate it easily.

Adverse reactions

Adverse effects derive from a long action of lorazepam. The central nervous system is usually affected, producing reactions such as:

  • Paradoxical effects
  • Dysarthria (difficulty speaking)
  • Sedation and ataxia (impaired coordination of movements)
  • Anterograde amnesia (recent memory isn’t remembered, but events prior to amnesia are).
  • Tolerance-dependence with rebound effect (treatment with lorazepam shouldn’t be stopped abruptly; it should be done gradually).

Therefore, caution must be exercised in people with an allergy to benzodiazepines, asthmatics, and patients with severe kidney failure. It can also be dangerous for pregnant women, as lorazepam is able to cross the placenta due to its high fat solubility.

Lorazepam should be taken under medical supervision

In no case should anxiolytic medications (or any other kind) be consumed without first consulting with the doctor. Also, many require a prescription from the doctor, because they aren’t available over the counter.

It’s also necessary to always bear in mind that only a health professional can determine whether a person needs to take a certain medication or not. So, if you think you need help, go for a consultation with a doctor or specialist and follow their instructions.

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