美国FDA批准ECR制药公司的骨骼肌松弛药盐酸环苯扎林(cyclobenzaprineHC1)缓释胶囊(商品名：Amrix)上市，用于解除急性骨骼肌疼痛引起的痉挛。剂量规格：盐酸环苯扎林15mg／粒，30mg／粒。环苯扎林解除局部骨骼肌痉挛而不干扰肌肉功能，对中枢神经系统引起的肌肉痉挛无效。在对健康男性志愿者(n=15)单剂研究中，AUC0-168与AUC0-∞的剂量平均算术计算值显示Amrix30mg约分别较Amrix15mg高16％和10％。Amrix30mg的Cmax约较Amrix15mg高20％。环苯扎林的T1／2和血药达峰时间两种剂量相近。
采用单剂Amrix30mg对健康成人志愿者(n=15)进行食物影响的研究显示。药物与食物同时服用的生物利用度较空腹服药在统计上显著提高。胃内有食物时，环苯扎林的Cmax增加35％，AUC0-168与AUC0-∞增加20％。以多剂Amrix30mg对健康成人志愿者(n=35)进行一日1次服用7日的研究，结果表明血药浓度达到稳态时环苯扎林的累积浓度为单剂的2．5倍。

盐酸环苯扎林缓释胶囊(AMRIX)

Cephalon公司近日表示AMRIX（盐酸环苯扎林缓释胶囊）的两项关键性试验结果显示与空白对照相比有效性获得肯定结果。AMRIX为一种每日一次的缓释骨骼肌松弛药，其效果与每日3次的普通环苯扎林制剂效果相当，AMRIX用于解缓下背与颈部的急性肌痉挛。此外与普通制剂相比AMRIX较少出现白天困倦的副作用。
公司官员说道：“典型的骨骼肌松弛药每天需要服用数次，患者较难坚持服用。AMRIX将为医生与患者提供一种方便的用药选择”。AMRIX寻求作为短时疗法（最多使用2-3周）用于减轻骨骼肌痉挛，将可能成为首种一天一次的骨骼肌松弛药，规格为每粒 15mg与30mg。

Amrix Extended-Release Capsules
nciation: SYE-kloe-BEN-za-preen
Generic Name: Cyclobenzaprine
Brand Name: Amrix

Amrix Extended-Release Capsules are used for:
Treating muscle spasms caused by painful muscle conditions. It should be used along with rest and physical therapy. It may also be used for other conditions as determined by your doctor.

Amrix Extended-Release Capsules are a muscle relaxant. It works in parts of the brain and nervous system to help reduce muscle spasms.

Do NOT use Amrix Extended-Release Capsules if:
•you are allergic to any ingredient in Amrix Extended-Release Capsules
•you have an overactive thyroid, liver problems, or certain heart problems (eg, irregular heartbeat, congestive heart failure, heart block, conduction problems), or if you have recently had a heart attack
•you are taking or have taken a monoamine oxidase inhibitor (MAOI)(eg,phenelzine, rasagiline) within the last 14 days

Contact your doctor or health care provider right away if any of these apply to you.

Before using Amrix Extended-Release Capsules:
Some medical conditions may interact with Amrix Extended-Release Capsules. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:
•if you are pregnant, planning to become pregnant, or are breast-feeding
•if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
•if you have allergies to medicines, foods, or other substances
•if you have a history of liver problems, heart problems, cerebral palsy, brain or spinal cord disease, or stroke
•if you have a history of glaucoma, increased pressure in the eye, or trouble urinating

Some MEDICINES MAY INTERACT with Amrix Extended-Release Capsules. Tell your health care provider if you are taking any other medicines, especially any of the following:
•MAOIs (eg, phenelzine, rasagiline) because serious, sometimes fatal reactions, including high fever and severe seizures, may occur
•Tramadol because the risk of seizures may be increased
•Droperidol or fluoxetine because severe heart problems, including irregular heartbeat, may occur
•Anticholinergics (eg, methscopolamine, benztropine), barbiturates (eg,phenobarbital), cimetidine, fluconazole, fluvoxamine, mibefradil, naproxen, or phenothiazines (eg, chlorpromazine) because they may increase the risk of Amrix Extended-Release Capsules's side effects
•Carbamazepine because it may decrease Amrix Extended-Release Capsules's effectiveness or increase the risk of Amrix Extended-Release Capsules's side effects
•Guanethidine or guanfacine because their effectiveness may be decreased by Amrix Extended-Release Capsules
•Sympathomimetics (eg, albuterol, epinephrine, phenylephrine) because their effectiveness may be decreased or the risk of their side effects may be increased by Amrix Extended-Release Capsules

This may not be a complete list of all interactions that may occur. Ask your health care provider if Amrix Extended-Release Capsules may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

How to use Amrix Extended-Release Capsules:
Use Amrix Extended-Release Capsules as directed by your doctor. Check the label on the medicine for exact dosing instructions.
•Take Amrix Extended-Release Capsules by mouth with or without food. If stomach upset occurs, take with food to reduce stomach irritation.
•Swallow Amrix Extended-Release Capsules whole. Do not break, crush, or chew before swallowing.
•Amrix Extended-Release Capsules works best if it is taken at the same time each day.
•Do not suddenly stop taking Amrix Extended-Release Capsules without checking with your doctor.
•If you miss a dose of Amrix Extended-Release Capsules, take it as soon as possible. If it is almost time for your next dose, skip the missed dose. Go back to your regular dosing schedule. Do not take 2 doses at once.

Ask your health care provider any questions you may have about how to use Amrix Extended-Release Capsules.

Important safety information:
•Amrix Extended-Release Capsules may cause drowsiness, dizziness, or blurred vision. These effects may be worse if you take it with alcohol or certain medicines. Use Amrix Extended-Release Capsules with caution. Do not drive or perform other possibly unsafe tasks until you know how you react to it.
•Talk with your doctor before you drink alcohol or use medicines that may cause drowsiness (eg, sleep aids, muscle relaxers) while you are using Amrix Extended-Release Capsules; it may add to their effects. Ask your pharmacist if you have questions about which medicines may cause drowsiness.
•Do NOT take more than the recommended dose or use for longer than 2 to 3 weeks without checking with your doctor.
•If your symptoms (eg, pain, tenderness, decreased range of motion) do not get better within 2 to 3 weeks or if they get worse, contact your doctor.
•Do not become overheated in hot weather or while you are being active; heatstroke may occur.
•If you experience dry mouth, use sugarless candy or gum, or melt bits of ice in your mouth. If dry mouth continues for more than 2 weeks, contact your dentist or doctor.
•Use of Amrix Extended-Release Capsules are not recommended in the ELDERLY; they may be more sensitive to its effects.
•Amrix Extended-Release Capsules has not been approved for use in CHILDREN; safety and effectiveness in children have not been confirmed.
•PREGNANCY and BREAST-FEEDING: If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using Amrix Extended-Release Capsules while you are pregnant. It is not known if Amrix Extended-Release Capsules are found in breast milk. If you are or will be breast-feeding while you use Amrix Extended-Release Capsules, check with your doctor. Discuss any possible risks to your baby.

Possible side effects of Amrix Extended-Release Capsules:
All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome:
Constipation; dizziness; drowsiness; dry mouth; fatigue; nausea; stomach pain or upset.

Seek medical attention right away if any of these SEVERE side effects occur:
Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); chest pain; confusion; fainting; fast or irregular heartbeat; mental or mood changes; numbness of an arm or a leg; one-sided weakness; seizures; severe dizziness or vomiting; speech or vision problems; sudden severe stomach pain; trouble urinating; yellowing of the skin or eyes.

This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider. Call your doctor for medical advice about side effects. To report side effects to the appropriate agency, please read the Guide to Reporting Problems to FDA.

If OVERDOSE is suspected:
Contact 1-800-222-1222 (the American Association of Poison Control Centers), your local poison control center, or emergency room immediately. Symptoms may include agitation; chest pain; coma; confusion; fast or irregular heartbeat; hallucinations; loss of coordination; seizures; severe drowsiness, dizziness, or nausea; slurred speech; tremor; vomiting.

Proper storage of Amrix Extended-Release Capsules:
Store Amrix Extended-Release Capsules at 77 degrees F (25 degrees C). Brief storage at temperatures between 59 and 86 degrees F (15 and 30 degrees C) is permitted. Store away from heat, moisture, and light. Do not store in the bathroom. Keep Amrix Extended-Release Capsules out of the reach of children and away from pets.

General information:
•If you have any questions about Amrix Extended-Release Capsules, please talk with your doctor, pharmacist, or other health care provider.
•Amrix Extended-Release Capsules are to be used only by the patient for whom it is prescribed. Do not share it with other people.
•If your symptoms do not improve or if they become worse, check with your doctor.
•Check with your pharmacist about how to dispose of unused medicine.

This information is a summary only. It does not contain all information about Amrix Extended-Release Capsules. If you have questions about the medicine you are taking or would like more information, check with your doctor, pharmacist, or other health care provider.