What You Need to Know About Diazepam
Diazepam is a drug in the benzodiazepine family that’s used to treat episodes of anxiety. It’s considered the most effective measure for the treatment of muscle spasms. It’s also used in patients with insomnia and alcohol withdrawal syndrome.
It’s a drug derived from 1,4-benzodiazepine that acts as a positive allosteric modulator of GABA-A receptors. It has different properties, including:
- Muscle relaxants
Diazepam is one of the most widely used benzodiazepines, both by outpatients and hospitalized patients. It was synthesized in the late 1950s by Leo Stembach at Hoffmann-La Roche.
Before going into detail regarding the characteristics of the drug and talking about how it exerts its action in the body, it’s important to know the diseases for which it’s prescribed, which are anxiety and muscle spasms.
What are anxiety and muscle spasms?
For starters, anxiety can be a normal emotion or a psychiatric disorder. Whether it’s one type or another will depend on the intensity and the impact on the patient.
In normal situations, it’s a component of normal mental activity that participates in defense mechanisms and allows us to adjust to stressful situations. However, if limits are exceeded, anxiety becomes pathological, nullifying, or hinders adaptation to the stressful situation.
Patients describe anxiety as a threatening feeling of tense expectation regarding the future and of disturbance of the psychosomatic balance in the absence of real danger. People with anxiety often suffer from the following:
At the same time, when it comes to muscle spasms, they can occur anywhere in the body. However, they often appear on one leg. They occur when the muscle contracts uncontrollably and doesn’t relax. They occur with mild or severe pain, which can cause these muscles to stiffen or bulge.
Throughout this article, we’ll look at the following aspects regarding diazepam:
- The mechanism of action
- Adverse reactions
The mechanism of action: What does the drug do in your body?
Benzodiazepines act at the level of the Central Nervous System and can cause all kinds of CNS depression. These effects include sedation and hypnosis, as well as skeletal muscle relaxation and anticonvulsant activity.
The molecular action of benzodiazepines is based on two facts:
- They facilitate the transmission of GABA, which is an inhibitory neurotransmitter that exerts its effects on specific receptor subtypes called GABA-A and GABA-B through a synergistic action at the postsynaptic level.
- They facilitate the binding of GABA to specific sites in the CNS, whose affinity determines the anxiolytic potency.
As we’ve said, they facilitate the transmission of GABA, which is an inhibitory neurotransmitter that exerts its effects on specific receptor subtypes called GABA-A and GABA-B, through a synergistic action at the postsynaptic level.
This is because they act on the GABA-A receptor producing an allosteric change, facilitating binding to this same receptor. In addition, they increase the frequency of the chloride channel tightening, which means that they enhance the inhibitory effect of this neurotransmitter.
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Pharmacokinetics: What happens to the drug in the body?
Diazepam is administered orally, rectally, and parenterally. Orally, it’s rapidly absorbed. In contrast, absorption after intramuscular injection is slow and erratic.
When administered rectally, it’s well absorbed with an absolute bioavailability of approximately 90% relative to intramuscular injection. Bioavailability is the concentration of a drug found in the bloodstream. which is available to carry out pharmacological action.
Pharmacological effects usually begin to be seen after the first dose. The onset of action after an intravenous dose is about 1-5 minutes. Furthermore, the duration of some clinical effects such as sedation or anticonvulsant activity is much shorter than would be expected considering that it has a long half-life.
Diazepam metabolism is primarily hepatic and involves demethylation reactions. The main metabolite is demethyldiazepam. However, it also produces two other metabolites, although they’re less active: Temazepam and oxazepam. All metabolic products are subsequently conjugated by glucuronation and excreted in the urine.
The adverse reactions of diazepam
The most common adverse effects include drowsiness, dizziness, ataxia, and disorientation. However, these effects rarely require discontinuation of benzodiazepine treatment. In addition, they’re easily treated by reducing the dose of the drug.
At times, agitation and excitement can occur. This “paradoxical reaction” is usually attributed to long-acting benzodiazepines. In these cases, it’s best to switch to a short-acting benzodiazepine, especially for patients with a history of aggressive and hostile behavior.
Hypotension and respiratory depression are seen with parenteral therapy, from time to time. On the other hand, liver disease or blood dyscrasias rarely appear.
Benzodiazepines show tolerance-dependence with a rebound effect. Therefore, diazepam treatment can’t be stopped abruptly. Rather, it has to be done gradually.
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- Calcaterra, N. E., & Barrow, J. C. (2014). Classics in chemical neuroscience: Diazepam (valium). ACS Chemical Neuroscience. https://doi.org/10.1021/cn5000056