Can I Experience Flexeril Side Effects the Next Day?

Flexeril is FDA-approved for treating mild to moderate musculoskeletal pain. It is intended for short-term use, but some users may experience side effects that last several hours or extend into the next day. While some next-day effects are common, users should be aware of the potential adverse effects that could happen during this time.

Flexeril Identification

Flexeril is the brand name for the generic medication cyclobenzaprine.[1] This medication belongs to the skeletal muscle relaxer class of drugs. It works by blocking nerve impulses, which are responsible for sending pain signals to the brain. Although it was previously prescribed to treat musculoskeletal conditions, including back pain, injury, and spasms, it is no longer being prescribed in the United States.[2] However, the generic version, cyclobenzapine, and the brand-name Amrix, are still available

Why Was Flexiril Discontinued in the United States?

Although some people still refer to cyclobenzaprine as Flexeril, this brand name is no longer available for sale in the United States.[3] The medication was discontinued by Merck in 2023 primarily due to economic reasons, such as the availability of cheaper generic versions. Many consumers preferred these generics over the more expensive Flexeril. While some might believe that safety or health concerns led to its discontinuation, the decision was mainly driven by market and cost factors.

What are the Side Effects of Cyclobenzaprine?

Flexeril is taken in measured doses for up to three weeks. During this time, you may experience several side effects that include:[4]

• Drowsiness
• lightheadednes
• Tiredness
• Headache
• Dry mouth
• Dizziness
• Upset stomach
• Nausea
• Constipation

If you experience any of the following serious side effects, reach out to your healthcare physician.[8]

These include symptoms of cardiovascular complications:

• Fast heartbeat
• Abnormal heart rhythm
• Chest pain
• Chest pressure
• Heart attack symptoms (radiating pain that spreads to the jaw or shoulder)
• Sudden numbness or weakness, especially on one side of the body.
• Slurred speech
• Poor balance

See immediate medical attention if you develop symptoms of serotonin syndrome, which include:[8]

• Agitation
• Hallucinations
• Fever
• Sweating
• Fast heart rate
• Shivering
• Muscle stiffness
• Muscle spasms
• Loss of coordination
• Nausea
• Vomiting
• Diarrhea

Serotonin syndrome is a life-threatening condition that requires rapid treatment to reverse.

What are the Signs of Flexeril Toxicity?

Taking Flexeril in large doses can result in cyclobenzaprine toxicity. The most common symptoms of toxicity include irregular heartbeat and drowsiness. However, in some rare cases, individuals who have overdosed on Flexeril may experience cardiac arrhythmias, cardiac arrest, severe low blood pressure, seizures, and neuroleptic malignant syndrome.

The treatment for Flexeril toxicity includes:[1]

• Gastrointestinal contamination, by way of a gastric lavage, followed by activated charcoal.
• Airway protection.
• Intravenous fluids.
• Intubation in cases of central nervous system (CNS) depression
• Providing benzodiazepines and anticonvulsants to individuals experiencing seizures

According to the National Library of Medicine, gastrointestinal lavage is only necessary in cases of cyclobenzaprine toxicity involving doses greater than 100 mg.[1]

Although it is rare, a cyclobenzaprine overdose can result in death.

Why Do People Experience Next-Day Side Effects After Taking Flexeril?

People can experience side effects the day after taking Flexeril due to its long half-life, which is the time needed for the body to reduce the drug by half. For Flexeril, this elimination half-life ranges from 1 to 3 days.[5] During this period, common side effects like drowsiness and upset stomach may occur. Since it takes approximately 5.5 to 16.5 days for the body to completely process Flexeril, side effects might persist throughout this timeframe.[5]

When Do Flexeril Side Effects Go Away?

It can take several days for the side effects of Flexeril to subside. This depends on how quickly your body processes the drug. Although it is estimated to have a complete elimination time of up to 16.5 days, some factors can alter this timeframe.

These factors include:[5]

• Frequency of your prescription intake
• Dosage amount
• A metabolism that is slower than average
• Advanced age
• Poor overall health
• Greater body mass

When to Contact a Healthcare Professional About Flexeril Side Effects?

If you experience symptoms long after your last use or notice symptoms of serotonin syndrome, contact your healthcare provider immediately. Similarly, if you encounter adverse side effects. Many of these symptoms will subside once the drug is no longer in your system and you discontinue using it.

Is Flexeril Addiction?

Cyclobenzaprine does not have physically addictive properties like other drug classes, such as diazepam or opioids. Therefore, it is not classified as a controlled substance by the DEA. However, if you misuse cyclobenzaprine by taking higher doses than prescribed, mixing it with illegal substances, or exceeding the recommended amount, you can develop a psychological dependence.[3]

Individuals who are psychologically dependent on cyclobenzaprine might face withdrawal symptoms when attempting to discontinue use. They might also develop a tolerance to the medication, reducing its effectiveness over time.

The signs of cyclobenzaprine withdrawal include:[3]

• Feeling unwell
• Nausea
• Headache

If you’re trying to quit cyclobenzaprine after experiencing symptoms of withdrawal, contact your doctor. They may prescribe a taper dose schedule. This allows you to withdraw from the medication safely and effectively.

Treatment for Cyclobenzaprine Abuse

Prescription drugs like cyclobenzaprine hydrochloride (Flexeril) can be very helpful in treating older adults and other individuals with pain that doesn’t improve with physical therapy or over-the-counter medications. However, access to these prescribed drugs increases the likelihood of misuse compared to street drugs.

According to the National Institute on Drug Abuse, misusing prescription drugs, such as Flexeril, can have serious medical consequences, which can include death from an overdose.[6] Still, millions of individuals abuse and misuse prescription drugs.

If you or someone you know is struggling to overcome Flexeril abuse, various treatment options are available to help.

These include:[7]

• Detoxification: This is a medically supervised program that allows you to withdraw from Flexeril safely and comfortably. Some clients are provided medications during this time to help them overcome withdrawal symptoms and cravings.
• Impatient treatment: Involves residing at a facility and following a treatment schedule. This schedule may include services like intensive counseling, drug education, and medications to help you overcome drug cravings and withdrawal.
• Outpatient treatment: This program allows you the flexibility of residing at home while attending the program. An OT program provides similar services to an inpatient treatment program, including peer support groups and holistic treatments.
• Behavioral therapy: This form of psychotherapy is often part of formal treatment and can be continued into aftercare programs. Behavioral therapy provides the coping skills necessary to overcome relapse, triggers, strengthen social relationships, and improve your ability to reintegrate and function well in your community.

To learn more about these programs or start your recovery journey, Southeast Addiction Center GA is here to assist. We offer personalized treatment plans tailored to maximize your chances of success. Our fully accredited facilities feature state-of-the-art amenities to ensure comfort and safety. Additionally, most insurance plans are accepted, making treatment accessible.

To learn more, contact us today.