偏头痛新药

偏头痛新药雷射替坦(Rizatriptan, 利扎曲坦, 利扎曲普坦)

雷射替坦是近年来发展的高选择性五-羟色胺(5-TH)受体激动剂。其优点是起效快。该药由Merck公司研制。在美国的商品名为Maxalt。

适应症：雷射替坦主要用于治疗急性偏头痛发作。口服10毫克雷射替坦1小时和2小时后，头痛缓解率分别为37%和70%。

作用机制：雷射替坦能选择性地刺激5-HT1b和5-HT1d受体。5-HT1b受体兴奋可引起血管收缩。激动5-HT1d受体能抑制三叉神经传入末梢释放多肽类致痛物质。实验证明5-HT1b和5-HT1d受体同时兴奋能降低三叉神经尾端核的兴奋性，减少头痛刺激的传入。雷射替坦能通过血脑屏障，同时具有中枢和外周的作用。

常见副作用：使用雷射替坦后病人可有口腔，颈部和胸部压迫感、头晕、疲劳、恶心、手脚麻木、发抖、严重者可见心绞痛、心率失常、心肌梗塞。

禁忌症：雷射替坦会引起血管收缩，如病人有周围血管病、心脏病史、心绞痛、冠心病、偏瘫型偏头痛及基底动脉型偏头痛应禁用此药。雷射替坦不宜与单胺氧化酶抑制剂和麦角类药物同用。也不能用于对本药有过敏者。

常用制剂和用量：雷射替坦一片5毫克，头痛发作时成人可口服5-10毫克雷射替坦。2小时候后如头痛持续，可再服5-10毫克。24小时最大剂量不能超过30毫克。

药理作用:

1.Rizatriptan is a headache medicine. It is believed to work by causing vasoconstriction (narrowing) of arteries and veins that supply blood to your head.

2.Rizatriptan is used to treat vascular headaches such as migraine headaches.

3.Rizatriptan may also be used for purposes other than those listed in this medication guide.

用法用量:

1.Take rizatriptan tablets exactly as directed by your doctor. If you do not understand these directions, ask your pharmacist, nurse, or doctor to explain them to you.

2.Take each oral dose with a full glass of water.

3.The orally disintegrating tablets (Maxalt-MLT) do not need to be taken with water or any other liquid. The tablet should be removed from the outer pouch and blister pack with dry hands, immediately before taking the pill. The tablet should then be placed on the tongue, where it will dissolve and be swallowed with the saliva.

4.Rizatriptan may be taken with or without food.

5.Take one tablet as soon as you notice symptoms of a migraine, or at any time during an attack.

6.If your symptoms improve only partially, or if they go away and then return, you can take another dose of rizatriptan unless your doctor directs otherwise. The second dose must be taken 2

hours or more after the first one. Never take more than 30 mg in any 24-hour period. If you are also taking propranolol (Inderal), no more than 15 mg should be taken in any 24-hour period, unless specifically directed otherwise by your doctor.

7.Store rizatriptan at room temperature away from moisture, heat, light, and the reach of children.

8.Throw away any unused medicine on the expiration date.

注意事项:

1 .Do not take rizatriptan if the headache you are experiencing is not like other migraines that you have had.

2.Do not take this medication if you have angina (chest pain) or if you have had a heart attack.

3.Never take more of this medication than is prescribed by your doctor. If your symptoms are not being treated, contact your doctor.

If Miss a Dose: Since rizatriptan is taken to treat migraine headaches as they occur and not to prevent them, missing a dose is not a problem. Take only the doses you need according to your doctor's instructions.

禁忌症:

1. You cannot take rizatriptan if you

have taken a monoamine oxidase inhibitor (MAOI) such as isocarboxazid (Marplan), tranylcypromine (Parnate), or phenelzine (Nardil) in the last 14 days;

have basilar or hemiplegic migraine headaches;

have had a heart attack, have angina (chest pain), or have another type of heart disease;

have had a stroke;

have Raynaud syndrome;

are experiencing a headache that is not like other migraines that you have had;

have taken another 5-HT agonist in the last 24 hours-5-HT agonists include sumatriptan (Imitrex), naratriptan (Amerge), and zolmitriptan (Zomig);

have taken an ergot-based medication within the last 24 hours--ergot-based medicines include methysergide (Sansert), ergotamine (Ergostat, Medihaler Ergotamine), dihydroergotamine mesylate (D.H.E.), and ergotamine combination products (Cafergot, Ercaf, Wigraine, Cafatine, Cafatine-PB, Cafetrate).

2.It may be dangerous to take rizatriptan if you have any of the conditions listed above.

3.Before taking this medication, tell your doctor if you

have high blood pressure,

have a family history of heart disease,

have high cholesterol (a type of fat),

are overweight,