药品名称:（包括商品名、通用名） 苯基丁酸钠 
用法用量
通常口服，病人体重小于20kg，给450～600mg(kg·d)，体重大的病人按体表面积9.9～13g/(m2·d)。本品剂量超过20g/d的安全性还未确定。本品可作为终生治疗或作为肝移植前的暂时治疗。可经口、经胃造瘘或鼻胃管给药。可将日剂量分3次混合于固体或液体食物中同服，但不可与酸性饮料同服。本品有很强的咸味，无令人不快的气味。
      
药理作用
本品是对尿周期紊乱病人长期治疗中的辅助药物。这种尿周期紊乱是一组少见的遗传病，它们每一种都涉及某种特殊的肝酶缺乏。这类疾病有严重程度的差别和首次发病年龄的不同，特征是以脲形成减少和从体内排氨能力降低，从而使血中的氨和谷酰胺升高以致发展成精神清醒程度的降低、含糊不清的语言、不稳定的步态、好斗，某些病人可出现严重的脑损伤。本品可辅助治疗包括氨甲酰磷酸合成酶、鸟氨酸转氨甲酰酶或精氨琥珀酸合成酶缺乏的尿周期紊乱。本品可用于新生儿（生后28d内）出现的酶完全缺乏的病人和后来发病的（出生1个月后）部分酶缺乏、有高氨血症脑病病史的病人。对这些病的诊断应尽可能迅速，并立即开始治疗以提高存活率。本品治疗必须结合限制饮食蛋白质，但在某些病例必须补充必需氨基酸。本品是一种前体药物，进入体内后迅速被代谢成为苯酯乙酸，与谷酰胺结合成为苯乙酰谷酰胺，由肾脏排出，并替代尿作为废物氮排泄的载体。使用本品可降低血浆氨和谷酰胺的浓度而增加废物氮以苯乙酰谷酰胺的形式排泄。新生儿病人过去几乎都在1年内死亡，然而，用血液透析及应用本品等药物，以及限制摄入饮食中的蛋白质，被诊断的新生儿，尽管精神发育延迟的发生率很高，但新生儿的存活率只在出生后的第1个月已经几乎升高80%。对迟发的病人，本品似有保护认知的功能。本品不能逆转已存在的神经损害和某些病人可能发生的神经退化。本品可减少急性高氨血症或高氨脑病的发病次数。
      
适应症
本品适应于少见的遗传特殊的肝酶缺乏症引起的体内氨排除障碍所致血氨和谷酰胺升高造成的脑神经损害。 
不良反应
最常见的是闭经或月经异常（占行经病人23%）、食欲减低（4%）、身体气味和味觉不良（3%）。实验室检查：酸中毒（14%）、低蛋白血症（11%）和贫血（9%）。
      
制剂
片剂：每片含本品500mg；粉剂：每克含本品0.94g。 
注意事项
本品大约含有125mg/g钠，因此，充血性心衰、严重肾功能障碍及钠潴留和水肿病人须慎用。本品属妊娠C类，孕妇有明显需要时可以应用。本品是否向乳汗分泌还不清楚。本品主要在肝脏和肾脏代谢，并且剂量的80%～100%在24h内以苯乙酰谷酰胺的形式由肾排出。肝、肾功能障碍者应小心监护。与内磺舒并同，可减少肾脏的排出。
      
How does it work?

Sodium phenylbutyrate is a prodrug that is rapidly converted to phenylacetate in the body.

Phenylacetate acts by combining with a naturally-occuring amino-acid called glutamine to form phenylacetylglutamine.
This is then removed from the body by the kidneys. This action is useful in patients with urea cycle disorders.

Urea cycle disorders are caused by inborn deficiencies of certain enzymes involved in the metabolism of amino-acids. Normally, when amino-acids are broken down, ammonia is produced which is converted into urea and removed from the body by the kidneys. In urea cycle disorders, the conversion to urea cannot take place and ammonia accumulates. This can seriously disturb brain function, producing the conditionknownashyperammonaemic encephalopathy.

This medicine provides an alternative method for the removal of excess amino-acids and ammonia from the bloodstream. It reduces raised blood ammonia and glutamine (an amino-acid) levels in patients with urea cycle disorders. It is used in conjunction with a controlled protein intake.

What is it used for?

Adjunctive therapy in the chronic management of urea cycle disorders

Warning!

Blood levels of ammonia, arginine, essential amino-acids and serum proteins should be maintained within normal limits. Plasma glutamine should be maintained at levels less than 1000 micromoles/L.

Sodium phenylbutyrate must be combined with dietary protein restriction and in some cases essential amino-acid supplementation.

This medicine contains a large amount of sodium.

If additional calories are required a protein-free product is recommended.

Use with caution inClinical conditions where there is sodium retention with oedema.

Congestive heart failure Decreased function of the liver (hepatic insufficiency)

Decreased kidney functionNot to be used inBreastfeeding Pregnancy

This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.

If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.

Pregnancy and BreastfeedingCertain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby.

Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.

This medicine should not be used in pregnancy. Seek medical advice from your doctor.

This medicine should not be used by breastfeeding mothers.
Discuss this with your doctor.

Side effects

Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Because a side effect is stated here, it does not mean that all people using this medicine will experience that or any side effect.

Headache

Depression

Blood disorders

Skin rashes
Disturbances of the gut suchasdiarrhoea,constipation,nausea,vomitingorabdominal pain

Weight gain

Abnormal heart beats (arrhythmias)

Inflammation of the pancreas (pancreatitis)

High blood uric acid level (hyperuricaemia)

which can cause kidney problems and goutAlteration in results of liver function tests

Ulceration of the stomach or intestine

Low blood potassium level (hypokalaemia)

Decreased appetite

Irregular menstrual periods

Partial or total failure of blood cell development (aplastic anaemia)

Alteration in tasteHigh blood phosphate content (hyperphosphateaemia)

Low blood phosphate level (hypophosphataemia)

Excessive fluid retention in the body tissues, resulting in swelling (oedema)

High blood sodium level (hypernatraemia)

Body odourStopping or absence of menstrual periods (amenorrhoea)

Alkaline body fluids and tissues (alkalosis)

Bleeding of the backpassage (rectum)

Unpleasant tasteHigh levels of chloride in the blood resulting in high acid levels (hyperchloraemic acidosis)

Fainting (syncope)

Increased acid levels in the blood (metabolic acidosis)

Small purplish blood spots in the skin (ecchymoses)

Low plasma albumin levels

The side effects listed above may not include all of the side effects reported by the drug's manufacturer.

For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.

How can this medicine affect other medicines?

When taken together with probenecid the removal of phenylacetylglutamine may be reduced.

Haloperidol and valproate induce hyperammonaemia. Corticosteroids may cause the breakdown of body protein and therefore increase blood ammonia levels.
More frequent monitoring of blood ammonia levels is advised when these medicines are used.