Flexeril: Uses, Side Effects, Precautions, and some common FAQs

All patients suspected of an overdose with FLEXERIL should receive gastrointestinal decontamination. This should include large volume gastric lavage followed by activated charcoal. If consciousness is impaired, the airway should be secured prior to lavage and emesis is contraindicated. Because of its atropine-like action, FLEXERIL should be used with caution in patients with a history of urinary retention, angle-closure glaucoma, increased intraocular pressure, and in patients taking anticholinergic medication.

• A long-acting formulation of cyclobenzaprine has been introduced and is believed by some clinicians to have a lower side effect profile than the immediate-release formulation of this drug.
• Hill slopes for cyclobenzaprine were similar to diphenhydramine in both mouse (−0.93 ± 0.04 and −0.90 ± 0.03, respectively) and rat (−1.1 ± 0.02 and −0.96 ± 0.1, respectively) H1R (Table 1).
• Because cyclobenzaprine is closely related to the tricyclic antidepressants, some of which are known to be excreted in human milk, caution should be exercised when FLEXERIL is administered to a nursing woman.
• Due to the lack of data in subjects with more severe hepatic insufficiency, the use of FLEXERIL in subjects with moderate to severe impairment is not recommended.

Interestingly, the difference in pA2 for Gα-RLuc/Gγ1-GFP dissociation was only ∼9-fold between cyclobenzaprine and diphenhydramine. This stark difference in pA2 values in the Ca+2 and BRET results is likely due to the nature of the aequorin-expressing HEK293 cells used in the former experiments. These cells stably express the mitochondrial aequorin Ca+2-binding protein, which is highly sensitive to even small kinetic increases in Ca+2, an effect that may be amplified compared with the BRET technique.

In such patients FLEXERIL should be initiated with a 5 mg dose and titrated slowly upward. Both cyclobenzaprine and methocarbamol have depressive effects on the central nervous system and can interact with other drugs that have a similar effect, such as benzodiazepines, opiate pain medications, and antidepressants. When these drugs interact, it can worsen side effects like drowsiness and dizziness. In these cells, cyclobenzaprine fully displaces [3H]-mepyramine from the H1R with a Ki of 3.2 ± 1.0 nM and a Hill slope of −1.1 ± 0.2 (Fig. 1A; Table 1). The displacement effects of cyclobenzaprine were apparent even at concentrations as low as 10 pM (–11 point, Fig. 1) in HEK293 cells.

Other Interactions

On the contrary, in the presence of 10 nM, 100 nM, or 1 μM cyclobenzaprine, the histamine-induced decrease in Gαq-RLuc8/Gγ1-GFP2 BRET was both right-shifted and insurmountable, confirming a non-competitive effect (Fig. 5B). PIC50s were shifted from −5.3 ± 0.1 to −4.9 ± 0.6 and −3.7 ± 0.2 in the presence of 10 nM and 100 nM, cyclobenzaprine, respectively, whereas the shift was incalculable for the 1 μM concentration due to flattening of the regression curve, as above. The resultant pA2 value of 8.57 (2.7 nM) corresponded precisely with the affinity of cyclobenzaprine what is flexeril used for pain for the human H1R (Fig. 2A). Importantly, and in contrast to diphenhydramine, the Emax of histamine in the presence of 10 nM, 100 nM, and 1 μM cyclobenzaprine was only 76% ± 3%, 39% ± 5%, and 33% ± 0% of that seen in the absence of antagonist, respectively (Fig. 5B). SIGNIFICANCE STATEMENT Cyclobenzaprine, a clinically used muscle relaxant that is strongly linked to sedation, demonstrates high-affinity noncompetitive antagonism at the histamine H1 receptor. This effect likely modulates the high degree of sedation that patients experience.

If your dose is different, do not change it unless your doctor tells you to do so. Because of the possibility of higher blood levels in the elderly as compared to younger adults, use of cyclobenzaprine extended-release capsules is not recommended in the elderly. This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information. In a pharmacokinetic study of sixteen subjects with hepatic impairment (15 mild, 1 moderate per Child-Pugh score), both AUC and Cmax were approximately double the values seen in the healthy control group.

Mouse cortex was dissected from flash-frozen brains from male mice obtained commercially from Innovative Research (Novi, MI). Structures of cyclobenzaprine (left) compared with the known sedating histamine H1 antagonists belonging to the tricyclic antidepressant family (top) or the first-generation arylethanolamine histamine H1 receptor antagonists (bottom). An overlay of cyclobenzaprine with a member of each is at right.

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The dosage ranges from 5 mg to 10 mg and it’s suggested you take it 3 times a day, as needed. As of this writing, cyclobenzaprine isn’t FDA-approved for children younger than 15. The long-acting capsules are recommended for patients 18 years of age and older and come in 15 mg doses. Some patients may require two doses equaling 30 mg at one time or two 15 mg doses twice a day. Long-acting capsules are not recommended for anyone under the age of 18.

Study raises concerns about tablet splitting – EurekAlert

Study raises concerns about tablet splitting.

Posted: Tue, 18 May 2004 07:00:00 GMT [source]

Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. There are countless underlying health conditions, external factors, and lifestyle choices that can cause or worsen insomnia symptoms. If pain is making it difficult for you to fall and stay asleep, you may want to consider pain medication or a muscle relaxer like cyclobenzaprine to help ease your discomfort and finally achieve the quality sleep you need. If you’re considering cyclobenzaprine as a muscle relaxer or a way to help ease short-term insomnia, you have to look at both the pros and cons. While all medications have potential risks and side effects, you need to determine if the pros outweigh the cons.

Cyclobenzaprine’s Effectiveness Timeframe

People with glaucoma, increased eye pressure, liver disease, and difficulty urinating may not react well to this particular muscle relaxer. Women who are pregnant, trying to get pregnant, or breastfeeding shouldn’t take cyclobenzaprine. Individuals over the age of 65 should consider alternative options to cyclobenzaprine. Studies show that there are other safer, more effective drugs for treating muscle pain and insomnia in older patients. Tell your doctor if you’re dealing with other medical conditions or health concerns in addition to muscle pain and insomnia.

Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are dizzy or are not alert and able to see well. If you cannot swallow the capsule whole, you may open the capsule and sprinkle the contents over one tablespoon of applesauce. Rinse the mouth to make sure all of the medicine have been swallowed. This medicine is available only with your doctor’s prescription.