FDA近日批准了Prestwick公司用于治疗亨廷顿舞蹈病(Huntington's Disease)的药物Xenazine (tetrabenazine)，这是首个在美国获准治疗该症的治疗药。它获准的依据是一项III期临床实验结果显示，这种具有选择性作用功能的多巴胺耗竭治疗药疗效显著，并且安全性和耐受性良好。
Prestwick表示Xenazine将在一项经FDA批准的风险评估项目下进行销售，这个评估项目主要防止该药有可能导致的抑郁和自杀倾向等不良反应。此前，该药也已被指定为罕见病治疗药，它在美国具有7年的独家销售权。
该药获准后在美国受到欢迎，当地约有3万名患者深受这种疾病的困扰。美国遗传性疾病基金会表示，舞蹈病不仅给患者带来不便，它还会严重影响患者在步行、说话、工作和看电视等各方面的能力。
目前，该药已在其他14个国家通过批准，新近获准的国家包括荷兰、瑞典和瑞士。
Indications and Usage:
XENAZINE® (tetrabenazine) is a medicine that is used to treat the involuntary movements (chorea) of Huntington’s disease . XENAZINE does not cure the cause of the involuntary movements, and it does not treat other symptoms of Huntington’s disease, such as problems with thinking or emotions.
It is not known whether XENAZINE is safe and effective in children.
Important Safety Information:
•XENAZINE can cause serious side effects, including:
◦depression
◦suicidal thoughts
◦suicidal actions
•You should not start taking XENAZINE if you are depressed (have untreated depression or depression that is not well controlled by medicine) or have suicidal thoughts.
•Pay close attention to any changes, especially sudden changes, in mood, behaviors, thoughts or feelings, or worsening depression. This is especially important when XENAZINE is started and when the dose is changed.
•Do not take XENAZINE if you have liver problems or are taking monoamine oxidase inhibitors or reserpine. Ask your doctor or pharmacist if you are not sure. At least 20 days should pass after stopping reserpine before starting XENAZINE.
•Tell your doctor if you are pregnant, breast-feeding or have breast cancer. Do not start any new medicines while taking XENAZINE without talking to your doctor first.
•The need for therapy should be eva luated on an ongoing basis with your doctor. The dose of XENAZINE should be adjusted slowly over several weeks for a dose that is appropriate for you. Tell your doctor if you stop taking XENAZINE for more than 5 days. Do not take another dose until you talk to your doctor. If your doctor thinks you need to take more than 50 mg of XENAZINE each day, you will need to have a blood test to see if a higher dose is right for you.
•Neuroleptic Malignant Syndrome (NMS) is a potentially fatal side effect reported with XENAZINE. Call your doctor right away and go to the nearest emergency room if you develop these signs and symptoms that do not have another obvious cause: high fever, stiff muscles, problems thinking, very fast or uneven heartbeat, or increased sweating. XENAZINE should be stopped immediately if NMS is diagnosed.
•XENAZINE can also cause other serious side effects, including: parkinsonism (slight shaking, body stiffness, trouble moving or keeping your balance), restlessness (akathisia), trouble swallowing, irregular heartbeat, and dizziness due to blood pressure changes when you change position (orthostatic hypotension). Trouble swallowing may increase the risk of pneumonia. Uncontrolled movements called tardive dyskinesia (TD) may also develop in patients treated with XENAZINE. It is possible that the TD will not go away.
•Side effects such as irregular heartbeat, NMS, and parkinsonism, may be increased when using XENAZINE with other drugs (e.g., dopamine antagonists).
•Sleepiness is a common side effect of XENAZINE; do not drive a car or operate dangerous machinery until you know how XENAZINE affects you. Alcohol and other drugs may increase sleepiness caused by XENAZINE.
•Some side effects, such as depression, tiredness, trouble sleeping, sleepiness, parkinsonism, agitation, and restlessness (akathisia), may be dose-dependent. If the side effects don’t stop or lessen, your doctor should consider lowering the dose or stopping your XENAZINE. The most commonly reported side effects in studies with XENAZINE were sleepiness, trouble sleeping, depression, tiredness, anxiety, restlessness, agitation and nausea.