Cyclobenzaprine, also known as Flexeril, is a prescription muscle relaxer that belongs to a similar class of antidepressants known as tricyclic antidepressants. The generic version of this drug was approved in 1977 and sold in both extended and immediate-release forms. Physicians prescribe cyclobenzaprine to treat short-term discomfort and pain caused by muscle injuries, including sprains, strains, and spasms.
Cyclobenzaprine is commonly used in conjunction with physical therapy for those with injuries, and the medicine helps to control muscle spasms that cause significant pain. Doctors will typically prescribe cyclobenzaprine as part of a treatment plan which includes physical therapy and rest. However, in some cases, the drug might be used to treat pain for those suffering from musculoskeletal disorders like fibromyalgia.
Cyclobenzaprine is highly effective in blocking pain sensations that travel from sore or spasming muscles to the brain by acting on the central nervous system. The drug can improve a person’s motor skills, sleep, and energy levels in those slowed down by severe muscle pain. However, despite its benefits, there are various adverse and potentially harmful side effects as well.
While the medication is proven beneficial, there are negative effects that can range from mild to severe and include the following:
Cyclobenzaprine can also cause severe side effects. If you experience any of the following effects, it’s important to call your doctor right away. If you believe your symptoms are life-threatening, you should immediately contact 911. Serious side effects and include the following:
Another potential and serious side effect of cyclobenzaprine is overdose, which can occur if an individual takes too much of the drug at once. Despite not producing a euphoric high you’d expect from another muscle relaxer like Valium, people will still use it for its relaxing effects. As you’d expect from other drugs, the effects will become less apparent over time, causing them to increase their dose to amplify the effects of relaxation.
An overdose of cyclobenzaprine may lead to severe health problems like dangerously low blood pressure, cardiac arrest, and seizures. In extreme cases, which are seen as the worst-case scenario, seizures, central nervous system depression, heart attack, and death can occur. Signs of a cyclobenzaprine overdose include hallucinations, chest pain, rapid heartbeat, vomiting, difficult breathing, slurred speech, and extreme drowsiness.
While overdosing on cyclobenzaprine is dangerous in and of itself, when you add other drugs into the equation, especially depressants like alcohol or benzodiazepines, it increases the danger exponentially. The combination may lead to respiratory depression and extreme drowsiness. Many people who abuse the drug are known to mix it with other depressants to increase the level of intoxication. You should never use cyclobenzaprine in conjunction with alcohol.
In its oral tablet form, cyclobenzaprine interacts with other herbs, vitamins, and medication a person might be using. What an interaction means is when a substance changes how the drug works, which can be harmful and prevent the medicine from working well.
To avoid interactions, you should speak with your physician about any over-the-counter medication or prescription drugs you’re using. This will help you determine how this medication will interact with something else you’re taking. Below we’ll describe some examples that may cause interactions with cyclobenzaprine.
You should never use cyclobenzaprine with monoamine oxidase inhibitors (MAOIs) because it may lead to dangerous side effects in the body. These drugs include the following:
Using this medication with an MAOI or within 14 days of stopping MAOIs might increase the odds of severe side effects, including seizures.
Using cyclobenzaprine with some medications and alcohol can increase the risk of side effects because it increases the amount of it in your body. An example of these drugs includes:
As discussed above, mixing muscle relaxers and alcohol is bad because of how the two affect your body. Alcohol and muscle relaxers both depress the central nervous system and work to slow brain activity, slowing down functions that include heart rate and breathing. These can also make you feel sleepy and sedated.
Since both drugs cause depressant effects, combining the two will compound the effects on your body, meaning the side effects of muscle relaxers, such as dizziness and drowsiness, will be intensified when drinking alcohol.
Mixing alcohol and muscle relaxers will intensify the effects of muscle relaxers, but not in a good way. They can lead to dangerous symptoms such as:
In addition to the apparent dangers, cyclobenzaprine and alcohol are both addictive substances, which can lead to an array of issues in the long term. Even using alcohol in moderation or taking cyclobenzaprine as prescribed can lead to addiction problems.
While alcohol and muscle relaxers don’t mix, there are some cases where they’re used for alcohol withdrawal, which is a condition that occurs when someone who’s been drinking for a prolonged period or in excess stops drinking. Symptoms can be deadly and include:
While they can be used in some cases, cyclobenzaprine is not sufficient in treating alcohol withdrawal.
If you’ve already mixed alcohol and cyclobenzaprine, you should stop drinking immediately. To err on the side of caution, you should contact a healthcare provider immediately, especially if you’ve consumed more than one drink and don’t do so very often. Since alcohol intensifies the effects of cyclobenzaprine, combining the two could lead to a fatal overdose.
If you’re using cyclobenzaprine with alcohol, it could indicate that you’ve developed an addiction if you’re trying to intensify the effects. Although medical experts don’t consider the drug addictive, there is evidence that cyclobenzaprine addiction is possible.
Since the drug depresses the central nervous system, some people find the effects to be desirable, leading to misuse. A person might abuse the drug to feel euphoric, relaxed, and sedated. Extreme doses of the drug produce various anticholinergic effects that alter brain neurotransmitter activity.
As a result of chronic use, cyclobenzaprine can lead to physical dependence, where a person will take higher doses of the drug because they don’t feel the pain-relieving effects they once did and develop an addiction as a result. In addition to addiction, cyclobenzaprine users may also deal with mild withdrawal symptoms when the drug is used in high doses.
Signs of cyclobenzaprine addiction include:
Another sign of addiction is abusing the medication in conjunction with other drugs, such as alcohol. Alcohol is the most commonly abused substance with muscle relaxers because it intensifies the effects. If you’re concerned about addiction, it may be time to reach out for help.
CDC (April 2021) Alcohol and Public Health. from https://www.cdc.gov/alcohol/
News In Health (October 2015) Biology of Addiction. from https://newsinhealth.nih.gov/2015/10/biology-addiction
FDA (April 2021) Valium. from https://www.accessdata.fda.gov/drugsatfda_docs/label/2016/013263s094lbl.pdf
CDC (April 2021) Fibromyalgia. from https://www.cdc.gov/arthritis/basics/fibromyalgia.htm
DEA (March 2021) Cyclobenzaprine. from https://www.deadiversion.usdoj.gov/drug_chem_info/cyclobenzaprine.pdf