Active Substance: bosentan monohydrate
Common Name: bosentan
ATC Code: C02KX01
Marketing Authorisation Holder: Actelion Registration Ltd.
Active Substance: bosentan monohydrate
Authorisation Date: 2002-05-15
Therapeutic Area: Hypertension, Pulmonary Scleroderma, Systemic
Pharmacotherapeutic Group: Antihypertensives
Treatment of pulmonary arterial hypertension (PAH) to improve exercise capacity and symptoms in patients with WHO functional class III.Efficacy has been shown in:
- Primary (idiopathic and familial) PAH
- PAH secondary to scleroderma without significant interstitial pulmonary disease
- PAH associated with congenital systemic-to-pulmonary shunts and Eisenmenger's physiology
Some improvements have also been shown in patients with PAH WHO functional class II (see section 5.1).
Tracleer is also indicated to reduce the number of new digital ulcers in patients with systemic sclerosis and ongoing digital ulcer disease (see section 5.1).
What is Tracleer?
Tracleer is a medicine that contains the active substance bosentan. It is available as orange and white ‘film-coated’ tablets (round: 62.5 mg; oval: 125 mg) and as pale yellow clover-shaped dispersible tablets (32 mg).
What is Tracleer used for?
Tracleer is used to treat patients with class III pulmonary arterial hypertension (PAH) to improve exercise capacity (the ability to carry out physical activity) and symptoms. PAH is abnormally high blood pressure in the arteries of the lungs. The ‘class’ reflects the seriousness of the disease: ‘class III’ involves marked limitation of physical activity. The PAH can be:
- primary (with no identified cause or familial);
- caused by scleroderma (also called systemic sclerosis, a disease where there is abnormal growth of the connective tissue that supports the skin and other organs);
- caused by congenital (inborn) heart defects with shunts (abnormal passageways) causing abnormal flow of blood through the heart and lungs.
Some improvements have also been shown in patients with class II PAH. ‘Class II’ involves slight limitation of physical activity.
Tracleer can also be used in adults with systemic sclerosis in whom poor blood circulation caused by the disease has led to the development of ‘digital ulcers’ (sores on the fingers and toes). Tracleer is intended to reduce the number of new digital ulcers that are formed.
Because the numbers of patients with PAH and with systemic sclerosis are low, the diseases are considered ‘rare’, and Tracleer was designated an ‘orphan medicine’ (a medicine used in rare diseases) on 14 February 2001 and on 17 March 2003.
The medicine can only be obtained with a prescription.
How is Tracleer used?
Treatment with Tracleer should only be started and monitored by a doctor who has experience in the treatment of PAH or systemic sclerosis.
Tracleer is taken morning and evening, with or without food. In adults, it should be started at a dose of 62.5 mg twice a day for four weeks and then increased to the usual dose of 125 mg twice a day. In children with PAH, the dose to use is calculated based on body weight, and usually starts at 2 mg per kilogram body weight twice a day.
Patients should swallow the film-coated tablets with water. The dispersible tablets are only for use in patients who cannot take the film-coated tablets. They should be dissolved in a little water on a spoon before being taken. The dispersible tablets have score lines so that they can be broken into quarters, each containing 8 mg bosentan. See the package leaflet for full details.
The doctor should assess the patient’s response to Tracleer and review the need for further treatment after eight weeks in patients with PAH who have not improved, and on a regular basis in patients with systemic sclerosis and ongoing digital ulcer disease.
Patients who take Tracleer must be given the special reminder card that summarises the safety information about the medicine.
How does Tracleer work?
The active substance in Tracleer, bosentan, blocks a naturally occurring hormone called endothelin-1 (ET-1), which causes blood vessels to narrow. Tracleer therefore causes blood vessels to expand.
PAH is a debilitating disease where there is severe narrowing of the blood vessels of the lungs. It causes high blood pressure in the vessels taking blood from the right side of the heart to the lungs. This pressure reduces the amount of oxygen that can get into the blood in the lungs, making physical activity more difficult. By expanding these blood vessels, the blood pressure is reduced and symptoms are improved.
In patients with systemic sclerosis and ongoing digital ulcer disease, bosentan improves blood circulation in the fingers and toes, preventing the development of new digital ulcers.
How has Tracleer been studied?
In PAH, Tracleer film-coated tablets have been studied in four main studies: two in a total of 245 adults with class III or IV disease that was either primary or caused by scleroderma, one in 54 adults with class III PAH that was associated with congenital heart defects, and one in 185 patients with class II disease. The studies compared Tracleer with placebo (a dummy treatment), when they were added to standard treatment. The main measure of effectiveness was how far the patients could walk in six minutes (a way of measuring exercise capacity), but the study in class II disease also looked at the change in the resistance to blood flow in the lungs’ blood vessels (a marker of how narrow the blood vessels are). A study was also carried out with the film-coated tablets in 19 children aged between three and 15 years. An additional study looked at the effects of Tracleer dispersible tablets in 36 children with PAH who were aged between two and 11 years.
In systemic sclerosis with digital ulcers, two studies have compared Tracleer film-coated tablets with placebo in a total of 312 adults. The main measure of effectiveness was based on the number of new digital ulcers developing during the studies. One of the studies also looked at the effect of Tracleer on healing in 190 patients, by measuring the time taken for one selected digital ulcer in each patient to heal completely.
What benefit has Tracleer shown during the studies?
In class III or IV PAH that was either primary or caused by scleroderma, the two studies showed that patients treated with Tracleer were able to walk further than patients treated with placebo after 16 weeks (44 metres further in the larger study), but there were too few patients with class IV disease to support the use of the medicine in this group. Similar results were seen in the patients with congenital heart defects.
In patients with class II disease, Tracleer caused the resistance of the blood vessels to decrease by 23% compared with placebo after six months of treatment, but the distance the patients could walk over six minutes was similar in the two groups.
Improvements were also seen in the study of children taking the film-coated tablets. In the study looking at the dispersible tablets, the levels of bosentan were lower than expected from the results of other studies, and could not be increased by using a higher dose of Tracleer. However, PAH seemed to remain stable in almost all of the children over 12 weeks of treatment, with most children remaining stable for at least 18 months.
In systemic sclerosis with digital ulcers, Tracleer was more effective at reducing the development of new digital ulcers than placebo. In the first study, patients taking Tracleer had an average of 1.4 new digital ulcers after 16 weeks, compared with 2.7 in the patients taking placebo. Similar results were seen in the second study after 24 weeks, but Tracleer did not have any effect on digital ulcer healing.
What is the risk associated with Tracleer?
In PAH, the most common side effects with Tracleer (seen in more than 1 patient in 10) are headache and abnormal results of tests carried out to check the liver. In patients with digital ulcers, the most common side effects (seen in more than 1 patient in 10) are abnormal liver tests, oedema (swelling) and fluid retention.
Because of the risk of liver problems, the doctor will measure the levels of liver enzymes before treatment, and every month during treatment with Tracleer. For the full list of all side effects reported with Tracleer, see the package leaflet.
The effectiveness of some medicines (such as the contraceptive pill) can be affected by taking Tracleer at the same time. See the package leaflet for full details.
Tracleer should not be used in people who may be hypersensitive (allergic) to bosentan or any of the other ingredients. It must not be used in patients who have liver problems, who are or could be pregnant, or who are taking ciclosporin A (a medicine that acts on the immune system).
Why has Tracleer been approved?
The Committee for Medicinal Products for Human Use (CHMP) decided that Tracleer’s benefits are greater than its risks for the treatment of patients with PAH and to reduce the number of new digital ulcers in patients with systemic sclerosis and ongoing digital ulcer disease. The Committee recommended that Tracleer be given marketing authorisation.
Tracleer was originally authorised under ‘exceptional circumstances’, because, as PAH is rare, limited information was available at the time of its initial approval for this disease. As the company had supplied the additional information requested, the ‘exceptional circumstances’ ended on 30 November 2004.
Which measures are being taken to ensure the safe use of Tracleer?
The company that makes Tracleer will provide an educational kit for prescribers and an information booklet for patients in each Member State, explaining the safety of Tracleer (especially its effects on the liver and in pregnancy) and its interactions. The company will also carefully control the distribution of the medicine in each Member State, and collect information on its use in patients with systemic sclerosis and ongoing digital ulcers.
Other information about Tracleer
The European Commission granted a marketing authorisation valid throughout the European Union to Actelion Registration Ltd on 15 May 2002. The marketing authorisation was renewed on 15 May 2007.
Source: European Medicines Agency
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