Benzodiazepines are a class of psychoactive drugs with varied uses, primarily in treating anxiety, insomnia, and seizures. Understanding the nuances of different benzodiazepines is crucial for healthcare professionals and patients alike. This Benzo Comparison Table provides a detailed overview of key pharmacological properties, including onset of action, half-life, and comparative oral doses. By examining these factors, we can gain a clearer picture of how different benzodiazepines work and how they compare to one another.
Key Factors in Benzodiazepine Comparison
When comparing benzodiazepines, several pharmacological properties are particularly important to consider. These include the onset of action, half-life, and comparative oral dose. Each of these factors plays a significant role in determining how a benzodiazepine works in the body and its clinical applications.
Onset of Action
The onset of action refers to how quickly the effects of a benzodiazepine are felt after administration. This is a critical factor, especially when treating acute conditions like panic attacks or severe anxiety. Benzodiazepines with a rapid onset of action provide quicker relief, which can be highly beneficial in such situations. As shown in the benzo comparison table, most benzodiazepines have a relatively rapid onset of action, typically ranging from 0 to 30 minutes.
Half-Life
Half-life is the time it takes for the body to metabolize and eliminate half of the drug’s concentration. This is a vital consideration as it dictates how long the effects of a benzodiazepine last and how frequently it needs to be dosed. Benzodiazepines with longer half-lives remain active in the body for extended periods, which can be advantageous for sustained relief but may also lead to accumulation and prolonged side effects, especially with regular use. Conversely, benzodiazepines with shorter half-lives may require more frequent dosing and are less likely to accumulate, but could also lead to withdrawal symptoms if discontinued abruptly after regular use. The benzo comparison table highlights the wide range of half-lives among different benzodiazepines, from as short as 1-4 hours to as long as 50-100 hours. It’s also important to note that the half-life often includes active metabolites, which can extend the overall duration of effects.
Comparative Oral Dose
The comparative oral dose provides a standardized measure of the potency of different benzodiazepines relative to a reference drug, typically Diazepam (Valium®). Since benzodiazepines vary significantly in their strength, comparing doses is essential for understanding their relative potency. This benzo comparison table uses Diazepam as the reference point, with a comparative oral dose of 10 mg. It’s crucial to recognize that these are comparative doses and individual responses can vary. Different sources may also provide slightly different equivalencies, as reflected in the table which compiles data from Ashton and ClinCalc.com. Understanding comparative doses helps in making informed decisions about medication choices and ensuring appropriate dosage adjustments when switching between different benzodiazepines.
Benzodiazepine Comparison Table
| Benzodiazepine | Onset of Action (min) | Half-life* (hrs) | Comp. Oral Dose**Ashton | Comp. Oral Dose**ClinCalc.com |
|---|---|---|---|---|
| Alprazolam (Xanax®) | 15-30 | 6-20 | 0.5 mg | 0.75 mg (0.5 – 2 mg) |
| Bromazepam (Lexotan®, others) | 15-30 | 8-30 | 3 mg | – |
| Chlordiazepoxide (Librium®, Limbitrol®) | 15-30 | 5-100 | 10 mg | 33 mg (12 – 50 mg) |
| Clobazam (Onfi®)*** | 20-30 | 42-47 | 20 mg | – |
| Clonazepam (Klonopin®, Rivotril®) | 15-30 | 18-39 | 0.5 mg | 0.75mg (0.5 – 4 mg) |
| Clorazepate (Tranxene®) | 15-30 | 50-100 | 7.5 mg | 13 mg (8 – 30 mg) |
| Diazepam (Valium®) (reference) | 0-15 | 20-100 | 10 mg | 10 mg |
| Flurazepam (Dalmane®) | 0-15 | 47-100 | 30 mg | 20 mg (8 – 30 mg) |
| Lorazepam (Ativan®, Loreev®) | 15-30 | 10-20 | 1mg | 1.3 mg (1 – 4 mg) |
| Midazolam po (Versed®) | 0-15 | 1-4 | – | 7 mg (5 – 10 mg) |
| Oxazepam (Serax®) | 30-60 | 3-21 | 15 mg | 20 mg (5 – 40 mg) |
| Quazepam (Doral®) | 15-30 | 28-114 | 5 mg | 27 mg (15 – 40 mg) |
| Temazepam (Restoril®) | 30-60 | 10-20 | 30 mg | 20 mg (5 – 40 mg) |
| Triazolam (Halcion®) | 15-30 | 1.6-5.5 | 0.5mg | 0.25 mg (0.25 – 1 mg) |
*Half-life is the time it takes for your body to metabolize half of the drug, and includes active metabolites (e.g., oxazepam is a metabolite of diazepam).
** Comparative Oral Dose: Since there is no standard, equivalencies vary between the sources. This table was compiled from the two sources shown in the table, and was checked against four others.[2,3,4,5]
*** Accumulates 23-fold over 2 weeks
Interpreting the Benzo Comparison Table
This benzo comparison table reveals significant differences in the pharmacology of various benzodiazepines. For instance, Diazepam (Valium®), used as the reference, has a rapid onset of action and a long half-life, making it suitable for managing acute anxiety and providing prolonged relief. In contrast, Triazolam (Halcion®) has a rapid onset but a very short half-life, making it more appropriate for short-term insomnia management, where a long duration of effect is not desired.
Alprazolam (Xanax®) and Clonazepam (Klonopin®) are often compared due to their common use in anxiety disorders. According to the table, Alprazolam has a slightly faster onset of action, while Clonazepam has a longer half-life. The comparative oral doses further illustrate potency differences. For example, the Ashton source suggests 0.5mg of Alprazolam is equivalent to 10mg of Diazepam, indicating Xanax is 20 times more potent than Valium. ClinCalc.com’s data provides a range, suggesting Xanax is 5-20 times stronger. Similarly, Clonazepam is shown to be significantly more potent than Temazepam. These potency variations underscore the importance of using comparative scales when discussing and prescribing benzodiazepines.
It’s also crucial to note the variability in comparative oral doses between different sources, as highlighted in the table. This variability stems from the lack of a single, universally accepted standard for benzodiazepine equivalency. Therefore, while this benzo comparison table provides a valuable guide, clinical judgment and individual patient response should always guide prescribing decisions.
Disclaimer: This benzo comparison table is for informational purposes only and should not be considered medical advice. Always consult with a healthcare professional for diagnosis and treatment decisions related to benzodiazepines.
