Treatment
Rebif (Interferon Beta-1a) ( refT5 )
Rebif is given as a sc (subcutaneous) injection under the skin, three times a week. The recommended dose is 44 µg (micrograms), although a lower dose of 22 µg is available. It is recommended that therapy with Rebif is initiated at 8.8 µg, then gradually increased over the first few weeks of therapy.
Because there is no clinical evidence on the effects of Rebif beyond 4 years of treatment, it is not known how long patients should be treated for. People taking Rebif should therefore be assessed by their physicians at least every 2 years during the first 4 years of treatment. Decisions about longer-term treatment can then be made on an individual basis.
As with all drugs, there are some cautions involved in the use of Rebif for some people.
Rebif is contraindicated for women who plan to become pregnant or who are pregnant. Women of child-bearing age should discuss the use of contraception. Nursing mothers may need to stop breast-feeding.
Like other interferon beta drugs, Rebif should not be used in children.
Rebif is contraindicated in people with severe depressive disorders or suicidal thoughts. In this case, Rebif should only be used with caution. Depression and suicidal ideation are conditions more common in people with MS. Before, or while taking Rebif, any symptoms of depression should be reported to the prescribing physician.
Rebif should also be used with caution in people with epilepsy that is not adequately controlled by treatment. People with epilepsy should inform their physician.
Rebif is contraindicated in people who are hypersensitive to interferon beta or any components of the drug. Patients taking Rebif are advised on a clean (aseptic) technique when using Rebif, and to change the injection site for each dose. Some patients, however, have reported a severe reaction at the injection site. This reaction, known as injection site necrosis, involves swelling and fluid leakage from a break in the skin at the injection site. If this occurs, patients should immediately consult their physician. If multiple reactions are observed, then the use of Rebif should be stopped.
People taking Rebif need to be monitored closely by their healthcare provider. Such monitoring may involve regular blood tests. People with cardiac disease (eg angina, heart failure, or arrhythmia) should be more closely monitored while taking Rebif. Tests of liver function may also be taken. Changes in liver function may require the dose of Rebif to be lowered or stopped completely. In both cases, people should tell their physician about any symptoms or history of any heart problems or liver disease.
There are some common side-effects associated with the use of Rebif. These include flu-like symptoms such as fever, chills, sweating, muscle aches and tiredness early during the course of treatment.
Less-common side-effects include: rash, diarrhoea, vomiting, palpitations, anxiety, dizziness, and thyroid problems.
Very rarely, people may have a hypersensitive reaction to Rebif.
People may develop neutralising antibodies to Rebif. This occurs because of the natural function of the immune system to raise antibodies against proteins such as interferon beta. Studies have shown that 24% of people taking the recommended 22 µg dose of Rebif for 2-4 years have neutralising antibodies. Because neutralising antibodies are associated with a reduction of biological effects, these antibodies may reduce the effectiveness of Rebif. If a patient has neutralising antibodies, and responds poorly to Rebif, the continued use of the treatment should be reassessed by the prescribing physician.
Licensed for MS in 1998, Rebif is marketed by Serono Ltd.
More detailed prescribing information on Rebif can be found by going to www.medicines.org.uk, typing Rebif into the search box and pressing Go.
The Association of British Neurologists provides guidelines on the use of interferon beta drugs (refT4). Among its recommendations are the suitability of people with MS for the treatment and the criteria that should be used to stop therapy.
Suitability of Patients:
Inteferon beta is an appropriate treatment for people with RR-MS provided they fulfil the following criteria:
1. Are able to walk independently.
2. Have had at least two clinically significant relapses in the last 2 years.
3. Are aged >18 years.
4. Have no contraindications (ie there is no medical reason why the patient should not
receive the treatment).
Stopping Criteria:
Treatment should be stopped in people taking interferon beta if there are intolerable side effects or if a pregnancy is planned. The treatment should also be stopped if it does not appear to be effective - for example, if:
1. The person experiences two disabling relapses within 12 months, as certified by a
neurologist.
2.
Secondary progressive MS
and disability occurs over a period of 6 months.
3. There is a loss of ability to walk, with or without assistance, for at least 6
months.