How Long For Diazepam To Work?

How Long For Diazepam To Work?

Diazepam, also known as Valium – read about its strength when compared to other muscle relaxers here – is a benzodiazepine medication. It is indicated to treat muscle spasms.

We know from Okoromah & Lesi’s (2004) review that regardless of the administration route of diazepam, it is an effective medication to treat muscle spasms. But, the length of time for you to experience the peak effect of this medication will vary according to many factors.

Typical times for onset of action

Diazepam is a well absorbed medication and is relatively fast-acting. The way in which you take the medication will affect how long you begin to experience a reduction in your symptoms. If you take the medication orally, typical onset of action is within 2 hours. A study by Mandelli et al (1978) found that peak blood concentrations of diazepam were reached within 90 minutes after oral administration.

Another way to administer this medication is through intramuscular injection. A study by Korttila & Linnoila (1977) found that intramuscular administration for diazepam led to an onset of action that was faster than oral administration. They found peak effect took around one hour.

A study by Kendall (1972) showed that if the drug is given to you intravenously, this is the method wherein the peak effect is experienced the quickest. Typical onset for action was shown in certain circumstances to be within six minutes.

Another way to administer diazepam is rectally. A study by Dreifuss (1998) found that peak serum plasma concentrations with this method of administration was reached within 5 to 45 minutes.

Other Factors Influencing Onset of Action

As mentioned above, the method in which you take diazepam can lead to a slower or faster onset of action. But there are other factors which may delay or hasten the peak effect for diazepam.

For example, if you are elderly, in particular with a declining liver function as diazepam is extensively metabolised in the liver by the cytochrome P450 enzymes – this will slow down the metabolism of the medication. This could potentially cause a delay in how long the medication takes to reach peak effect.

If you are also taking other medications at the same time as taking diazepam, this may also cause a delay in the time for peak effect. Specifically, if you are taking medications that inhibit or induce the cytochrome p45 enzymes such as rifampicin, phenytoin and erythromycin. This types of medications will have an influence on the p450 enzymes which may affect the normal metabolism of diazepam.

How much food you have eaten will also lead cause a delay in peak effect. If you have eaten a meal with a high fat content, this will delay diazepam’s absorption, as this type of food in general delays food’s movement from the stomach. A delay in its absorption will cause

If you are a chronic user of diazepam that can lead to tolerance. This means that higher doses are required to achieve the same effect.

As you can see there are several factors that can influence the speed that diazepam onsets. Whenever you are being prescribed this type of medication, your healthcare provide must use these factors in their prescribing decision.

If you are in pain with muscle spasms, you can consult with me here.

References

1. Mandelli, M., Tognoni, G., & Garattini, S. (1978). Clinical Pharmacokinetics of Diazepam. Clinical Pharmacokinetics, 3(1), 72–91. https://doi.org/10.2165/00003088-197803010-00005

2. Korttila, k., & Linnoila, m. (1975). absorption and sedative effects of diazepam after oral administration and intramuscular administration into the vastus lateralis muscle and the deltoid muscle. british journal of anaesthesia, 47(8), 857–862. https://doi.org/10.1093/bja/47.8.857

3. Okoromah, C. A., & Lesi, A. F. (2004). Diazepam for treating tetanus. Cochrane Database of Systematic Reviews. https://doi.org/10.1002/14651858.cd003954.pub2

4. P. Hume Kendall. (1964). Use of Intravenous Diazepam in Acute Skeletal Muscle Spasm Preliminary Report. Rheumatology, VII(suppl 1), 14–15. https://doi.org/10.1093/rheumatology/vii.suppl_1.14

5. Milligan, N., Dhillon, S., Oxley, J., & Richens, A. (1982). Absorption of Diazepam from the Rectum and Its Effect on Interictal Spikes in the EEG. Epilepsia, 23(3), 323–331. https://doi.org/10.1111/j.1528-1157.1982.tb06198.x#

6. Dreifuss, F. E., Rosman, N. P., Cloyd, J. C., Pellock, J. M., Kuzniecky, R. I., Lo, W. D., Matsuo, F., Sharp, G. B., Conry, J. A., Bergen, D. C., & Bell, W. E. (1998). A comparison of rectal diazepam gel and placebo for acute repetitive seizures. The New England Journal of Medicine, 338(26), 1869–1875