"Sept. 14, 2011 -- Low doses of the muscle relaxant cyclobenzaprine, taken at bedtime, help people with fibromyalgia sleep better and feel less pain, according to a small study.
"Bedtime treatment of fibromyalgia patients with low-dose"...
(cyclobenzaprine hydrochloride) Extended-release Capsules
AMRIX is a skeletal muscle relaxant which relieves muscle spasm of local origin without interfering with muscle function. The active ingredient in AMRIX extended-release capsules is cyclobenzaprine hydrochloride, USP. Cyclobenzaprine hydrochloride (HCl) is a white, crystalline tricyclic amine salt with the empirical formula C20H21N•HCl and a molecular weight of 311.9. It has a melting point of 217°C, and a pKa of 8.47 at 25°C. It is freely soluble in water and alcohol, sparingly soluble in isopropanol, and insoluble in hydrocarbon solvents. If aqueous solutions are made alkaline, the free base separates. Cyclobenzaprine HCl is designated chemically as 3-(5H-dibenzo[a,d] cyclohepten-5-ylidene)-N,N-dimethyl-1-propanamine hydrochloride, and has the following structural formula:
AMRIX extended-release capsules for oral administration are supplied in 15 and 30 mg strengths. AMRIX capsules contain the following inactive ingredients: diethyl phthalate NF, ethylcellulose NF (Ethocel Standard 10 Premium), gelatin, Opadry® Clear YS-1-7006, sugar spheres NF (20-25 mesh), and titanium dioxide. AMRIX 15 mg capsules also contain D&C yellow #10, FD&C green #3, and FD&C red #40. AMRIX 30 mg capsules also contain FD&C blue #1, FD&C blue #2, FD&C red #40, and FD&C yellow #6.
What are the possible side effects of cyclobenzaprine (Amrix, Comfort Pac with Cyclobenzaprine, Fexmid, Flexeril)?
Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Stop using cyclobenzaprine and call your doctor at once if you have any of these serious side effects:
- fast, pounding, or uneven heartbeats;
- chest pain or heavy feeling, pain spreading to the arm or shoulder, nausea, sweating, general ill feeling;
- sudden numbness or weakness, especially on one side of the body;
- sudden headache,...
What are the precautions when taking cyclobenzaprine hcl extended-release capsules (Amrix)?
Before taking cyclobenzaprine, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
Before using this medication, tell your doctor or pharmacist your medical history, especially of: liver disease, overactive thyroid (hyperthyroidism), heart problems (such as irregular heartbeat, heart block, heart failure, recent heart attack), difficulty urinating (such as due to an enlarged prostate), glaucoma.
This drug may make you dizzy or drowsy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. Avoid alcoholic...
Last reviewed on RxList: 6/20/2013
This monograph has been modified to include the generic and brand name in many instances.
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