Multiple sclerosis, or MS for short, is a chronic and progressive demyelinating disease of the central nervous system. Myelin is the protective sheath that surrounds the axons of neurons, allowing them to quickly send electrical impulses. In MS, demyelination happens when the immune system inappropriately attacks and destroys the myelin. As a result communication between neurons breaks down, ultimately leading to various sensory, motor, and cognitive problems. Although there’s no cure for MS, disease-modifying therapy can be used to help slow the disease progression, as well as mitigate some of the symptoms, and ultimately improve the client’s quality of life.
Now, disease-modifying therapy for MS includes monoclonal antibodies and immunomodulators. The most commonly used monoclonal antibodies for MS include rituximab, natalizumab, ocrelizumab, and alemtuzumab, which are administered intravenously. On the other hand, immunomodulators for MS include dimethyl fumarate, teriflunomide, and fingolimod, which are administered orally, as well as glatiramer and recombinant human interferon beta-1a and interferon beta-1b, which can be injected intramuscularly or subcutaneously.
Once administered, these medications blunt the inflammatory process, which ultimately helps reduce the severity and frequency of relapses or exacerbation of multiple sclerosis.
Unfortunately, these medications can cause side effects like bone marrow suppression, which can result in anemia, thrombocytopenia, leukopenia, and an increased risk for infections. In fact, for alemtuzumab, that’s a boxed warning, with an increased risk of developing fatal infections, autoimmune effects, and malignancy.
Clients on disease-modifying therapy may also experience drowsiness, fatigue, nausea, vomiting, and diarrhea. These medications may also result in hypersensitivity reactions, such as injection site reactions, Stevens-Johnson syndrome, toxic epidermal necrolysis, and anaphylaxis, while alemtuzumab and rituximab have a boxed warning for potentially causing fatal infusion reactions after administration, and rituximab may also cause fatal mucocutaneous reactions.
In addition, these medications can also lead to cardiotoxicity, as well as hepatotoxicity, and that’s a boxed warning for teriflunomide! On the other hand, natalizumab and rituximab have a boxed warning for increasing the risk of developing progressive multifocal leukoencephalopathy, or PML for short; clients at greater risk include those who present with anti-JC virus antibodies, as well as those on therapy for a prolonged period of time, and those with prior use of immunosuppressants. Finally, rituximab also has a boxed warning for the reactivation of hepatitis B virus or HBV.
As far as contraindications go, the monoclonal antibodies natalizumab and rituximab are obtained using both human and murine genes, so they’re contraindicated in clients with hypersensitivity to murine proteins. In addition, natalizumab and rituximab have a boxed warning against its use in clients with any symptoms that may suggest progressive multifocal leukoencephalopathy, while rituximab is also contraindicated in clients with an active HBV infection or those who develop reactivation of HBV.
On the other hand, teriflunomide has a boxed warning against its use during pregnancy, while the rest of these medications should be used with extreme caution. Additional precautions include breastfeeding, immunosuppression, and clients with cardiovascular, hepatic, or renal disease.
Now, if a client with MS is prescribed natalizumab, start by assessing your client's current symptoms like fatigue, problems with balance, visual impairment, and urinary urgency. Then, assess their weight and vital signs; and check their most recent laboratory test results, including CBC, and their renal and liver function tests.
Next, explain to your client that the medication will help treat their MS symptoms, and that it will be administered intravenously every four weeks.