Tag Archives: Antihistamines

Understanding and managing insomnia in MS

Insomnia is the most common sleep disorder I encounter in my MS practice. It often goes untreated because people with MS accept it as part of living with the disease or because healthcare professionals (HCPs) prioritise other MS-related problems.

Key points

  • Insomnia is more common in people with MS than in the general population and is associated with poor mental health and other medical problems.
  • Factors that contribute to insomnia include anxiety, frequent visits to the bathroom, pain, leg spasms, restless legs, inability to roll over in bed, menopausal symptoms (hot flushes and night sweats) and poor sleep hygiene; they need to be managed appropriately.
  • Several online tools and questionnaires exist that can help you assess the nature and severity of insomnia.
  • Sleep aids (drugs) available over the counter or on prescription may be helpful.
  • Cognitive and digital approaches to insomnia management also have a role but are not widely available or suitable for everyone.
  • Complementary and alternative therapies are a valuable aid to self-management of insomnia.

Sleep, glorious sleep!

Sleep is the most essential performance-enhancing agent we know. You know what it is like if you wake in the morning and have had a good night’s sleep; you feel energised, your mood is good and you are ready to face the day. In contrast, when you wake from a night of tossing and turning, or not being able to turn, legs jerking, getting up several times to go to the toilet, maybe with a hangover from too much alcohol the night before, then you are irritable, your mood is low and it is challenging to get through the day. 

Most studies on sleep in MS show that over 70% of people with MS have a sleep disorder. In an MS-Selfie survey on sleep, a minority (33%) of 173 respondents described their sleep as good, very good or excellent, with 49% formally diagnosed with one or more sleep disorder and over 80% not having undergone formal sleep studies. Insomnia is the most common sleep disorder I encounter in my MS practice. Insomnia is defined as difficulty initiating or maintaining sleep, which can be a symptom or a disorder. If a disorder, insomnia is associated with a feeling of distress about poor sleep, and it disrupts social or occupational functioning.

Causes and impact of insomnia

In the general population, ~10% of adults have insomnia disorder and another 15 ̶ 20% report occasional insomnia, i.e. the symptom. In comparison, 40 ̶ 50% of people with MS have insomnia. Insomnia is more common in women than in men and is associated with poor mental health and other medical problems. Common MS-associated symptoms linked to insomnia (and resulting in fatigue) include pain, lack of bladder control, spasticity, restless legs, periodic limb movements and discomfort from being unable to turn in bed; other factors that contribute to insomnia – not just in people with MS but also more widely –  include alcohol and stimulant misuse, menopausal symptoms, poor sleep hygiene (daytime napping), deconditioning (lack of exercise), anxiety and depression. All these problems can interfere with sleep initiation, maintenance or perception in people with MS.

Insomnia can be episodic (with symptoms lasting 1 ̶ 3 months) or situational (of short duration, in response to a specific event of circumstance) and tends to follow a persistent course. Episodic insomnia refers to insomnia for a defined period, for example lasting several months linked to anxiety. In comparison, situational insomnia refers to insomnia triggered by a specific stimulus or event, such as sleeping away from home or after alcohol consumption. Chronic insomnia can cause depression and is associated in the general population with the development of hypertension and dementia. Insomnia assessment, diagnosis and management require a careful history to document its course, concomitant comorbidities and potential contributing factors. 

Several studies show that approximately 40% of people with MS have obstructive sleep apnoea and that it is not necessarily associated with obesity and a large neck. Sleep apnoea in MS may be due to brain stem pathology from MS affecting pharyngeal (throat) muscle function. If you know or think you are a snorer and you have periods when you stop breathing, you can download one of the many smartphone sleep apps that can assess this.

Approaches to managing insomnia

Any MS-related symptoms that can affect sleep need to be managed appropriately. How can you treat insomnia if your sleep is interrupted by anxiety-related rumination, nocturia, pain, leg spasms, restless legs, inability to roll over in bed, menopausal symptoms of hot flushes and night sweats and poor sleep hygiene

Recording your sleep patterns

A 24-hour history of sleep ̶ wake behaviours can help to identify additional behavioural and environmental factors for intervention. Patient-reported outcome measures (PROMS) and sleep diaries provide valuable information about the nature and severity of insomnia. They can help screen for other sleep disorders and monitor treatment progress.

A sleep diary should collect information on your sleep cycle (bedtime, arising time, napping) and estimates of your sleep ̶ wake characteristics, i.e. sleep latency (how long it takes to fall asleep), number and duration of awakenings, and an estimated overall sleep time. Useful PROMS include the Insomnia Severity Index, the Pittsburgh Sleep Quality Index, the STOP-BANG Sleep Apnea Questionnaire (for evaluating the risk of sleep apnoea) and the Restless Legs Syndrome Rating Scale

Sleep hygiene

I suggest you start with a simple self-help guide to improve your sleep hygiene.

  1. Ensure you spend an appropriate amount of time asleep, at least 6 hours in bed. Some people need more than this to feel refreshed. 
  2. Limit daytime naps to 30 minutes. Please note that napping does not make up for inadequate nighttime sleep. 
  3. Avoid stimulants such as caffeine, modafinil and nicotine close to bedtime. 
  4. Only drink alcohol in moderation. Alcohol is known to help you fall asleep faster, but too much disrupts sleep.
  5. Exercise helps improve sleep quality. As little as 10 minutes of aerobic exercise daily can enhance the quality of sleep. 
  6. Don’t eat before going to bed. Heavy foods and fizzy drinks can trigger indigestion or heartburn/reflux that disrupts sleep.
  7. Ensure you get adequate exposure to natural light; exposure to sunlight during the day and darkness at night help to maintain a regular sleep ̶ wake cycle. 
  8. Establish a regular relaxing bedtime routine, which helps the body recognise it is bedtime. This could include taking a shower or bath or reading. However, avoid reading or watching emotionally upsetting content before attempting to sleep.
  9. Make sure that your sleep environment is pleasant. Your mattress and pillows should be comfortable. The bedroom should be cool for optimal sleep (16 ̶ 20°C). The bright light from lamps, smartphones and television screens can make it difficult to fall asleep, so turn those lights off or adjust them when possible. Use the blue filter mode on your smartphone and other devices to reduce the inhibition of melatonin from light. Consider using blackout curtains, eyeshades, earplugs, white noise machines and other devices to make the bedroom more relaxing.
  10. If you have pain, nocturia, restless legs, sleep apnoea or other causes of discomfort, get these adequately managed via your HCP.

If these self-help measures fail, other current treatment options include prescription-only and over-the-counter (OTC) medications, cognitive behavioural therapy for insomnia (CBTI) and complementary and alternative therapies. 

Over-the-counter sleep aids

Over-the-counter sedatives tend to be first-generation antihistamines with potent centrally acting anticholinergic effects that impair cognitive function and long-term brain health. I recommend you avoid them (see newsletter entitled ‘Your anticholinergic burden’). 

Some people with MS self-medicate with OTC melatonin, cannabidiol (CBD) or tetrahydrocannabinol (THC) preparations. Melatonin has a U-shaped dose ̶ response curve for some individuals; therefore, lower doses may be better than higher doses. In general, I cannot recommend the use of CBD or THC for insomnia. CBD is a drug and is associated with liver toxicity; it may also interact with your other medications. However, if you do decide to buy CBD and/or THC, please use a reputable supplier and pharmaceutical-grade products. Medicinal cannabis cannot be prescribed on the NHS but can be obtained via private clinics. Many patients purchase it online; as a doctor, I cannot recommend buying it this way. 

Prescription-only sleep aids

If you raise the issue of insomnia with your HCP, they may reach for the prescription pad. Before accepting a sedative, please be aware of its limitations and ensure you have optimised all the above guidance. Sedatives are only a short-term solution; they work well for about 4 ̶ 5 days before you develop tachyphylaxis and need higher doses. Tachyphylaxis refers to the rapidly diminishing response to successive doses of a drug, rendering it less and less effective. Once you develop tachyphylaxis and stop taking sedatives, you may experience rebound insomnia. Benzodiazepines (e.g. diazepam) are addictive and doctors generally avoid prescribing them for insomnia. However, they still have a role when insomnia is part of acute anxiety. The sedatives most often used are the so-called Z-drugs (zolpidem, zopiclone, zaleplon and eszopiclone). Zopiclone and eszopiclone have a longer half-life than the other two drugs (5 ̶ 6 hours). In comparison, zolpidem and zaleplon act for a much shorter period (1 ̶ 3 hours). 

The older, tricyclic antidepressants, such as amitriptyline, are commonly used as sedatives. I have largely stopped prescribing them unless there is another reason for using a tricyclic, e.g. to help with pain management (please read my newsletter ‘Amitriptyline: the neurologist‘s dirty little secret’. I mostly use duloxetine in my clinical practice for pain management. It is not as sedating as tricyclic antidepressants, but some patients find it helps with sleep. Duloxetine is a serotonin ̶ noradrenaline reuptake inhibitor and has fewer anticholinergic side effects than tricyclics.

Antispasticity agents such as baclofen and gabapentinoids (gabapentin and pregabalin) also help sleep, but they should only be used for insomnia if you have spasticity or, in the case of the gabapentinoids, spasticity and/or pain that needs to be managed.  

Psychiatrists and some neurologists use sedating antipsychotics to help with insomnia. Sadly, as a neurologist, I have seen too many severe adverse events resulting from the liberal use of antipsychotics as sedatives. There needs to be a good reason for prescribing an antipsychotic, and insomnia in isolation is not one of them; however, there is a role for them in patients with cognitive issues or significant psychiatric problems. The older generation antipsychotics (e.g. haloperidol) have now been replaced by safer drugs such as quetiapine and olanzapine.

A new class of sedatives is now available in some countries; these are the dual orexin receptor antagonists suvorexant, lemborexant and daridorexant. Daridorexant is NICE approved for use by the NHS; it is recommended for treating insomnia in adults with symptoms lasting for 3 nights or more per week for at least 3 months and whose daytime functioning is considerably affected, but only if CBTI has been tried and not worked, or if CBTI is not available or is unsuitable.

Cognitive approaches to managing insomnia

Cognitive Behavioural Therapy for Insomnia (CBTI)

Only some patients receive CBTI, owing to a lack of adequately trained therapists. CBTI aims to change the behaviour and psychological factors that contribute to insomnia (e.g. anxieties and unhelpful beliefs about sleep). At the core of CBTI are behavioural and sleep-scheduling strategies (sleep restriction and stimulus control instructions), relaxation methods, psychological and/or cognitive interventions to change unhelpful beliefs or excessive worrying about insomnia, and sleep hygiene education. 

CBTI is focused on sleep and oriented toward problem-solving. A psychologist typically guides the process over roughly six consultations. Several variants in the methods for implementing CBTI include shorter formats, group therapy, using other providers such as counsellors and specialist nurses, and the use of telehealth digital platforms, including smartphone applications. 

Brief behavioural treatment for insomnia

This abbreviated version of CBTI emphasises behavioural components and is typically implemented in fewer sessions. It involves education about sleep regulation, factors that promote or interfere with sleep, and a tailored behavioural prescription based on stimulus control and sleep restriction therapy.

eCBTI

Digital CBTI (eCBTI) is becoming increasingly popular. The Sleepio application, which is recommended and covered by the NHS, has a positive effect on several sleep outcomes and is said to be as effective as medication. NICE recommends Sleepio as a cost-saving option for treating insomnia and insomnia symptoms in primary care for people who would otherwise be offered sleep hygiene or sleeping pills. A medical assessment should be done before referral to Sleepio for people who may be at higher risk of other sleep disorder conditions, such as during pregnancy or in people with comorbidities.

Complementary and alternative therapies

Sleep restriction

Limit the time you spend in bed to match your sleep time as closely as possible. After the initial restriction, the sleep window can be gradually adjusted upward or downward on a weekly basis as a function of sleep efficiency (time asleep÷time spent in bed×100) until an appropriate sleep duration is established.

Stimulus control

You need to follow a set of instructions designed to reinforce the association between bedtime and bedroom stimuli with sleep and to re-establish a consistent sleep ̶ wake schedule.

  • Go to bed only when you feel sleepy.
  • Get out of bed when you are unable to sleep.
  • Use the bed and bedroom for sleep and sex only; do not use your bed for reading, watching television, etc.
  • Try and get up at the same time every morning.
  • Avoid napping.

Relaxation training

Try using different procedures such as progressive muscle relaxation and imagery training to reduce arousal, muscle tension and intrusive thoughts that interfere with sleep. Relaxation procedures need to be practised daily over a few weeks. 

Cognitive therapy

This is a psychological approach to revising many common misconceptions about sleep and reframing unhelpful beliefs about insomnia and its daytime consequences. This method also reduces excessive worrying about sleep difficulties and their daytime consequences. Additional cognitive strategies include paradoxical intention (willingly trying to stay awake rather than trying to fall asleep) to alleviate the performance anxiety triggered by attempting to force sleep.

Sleep hygiene education

These general guidelines include advice about a healthy diet, exercise, substance use, and optimising environmental factors such as light level, noise and excessive temperature that may promote or interfere with sleep (see above). 

Acceptance and commitment therapy (ACT)

ACT is a form of psychotherapy that aims to educate people to stay focused on the present moment and accept life experiences, thoughts, and feelings (even negative ones) without trying to change them. ACT uses different methods and processes (e.g. acceptance, defusion, mindfulness, and committed action) to increase psychological flexibility.

Mindfulness

This meditation method involves observing one’s thoughts and feelings and letting go of the need to change or ruminate. Originally designed to reduce stress and anxiety, mindfulness has been adapted for the management of insomnia and can be included as one component of ACT.

Conclusion

Poor sleep, be it due to a comorbid sleep disorder, MS-related symptoms or poor sleep hygiene, is a very common problem in people with MS. It contributes to daytime fatigue and hypersomnolence and impacts physical and cognitive function. As a result, poor sleep reduces quality of life and can exacerbate other MS-related problems such as poor cognition, anxiety and depression. It is essential that poor sleep is documented, investigated appropriately and treated accordingly to improve the functioning and quality of life of people with MS.

How can I reduce my chances of adverse events on specific DMTs?

The complications associated with immunosuppression vary from DMT to DMT. You will find it helpful to understand what investigations to expect before and during treatment and how these may vary depending on the DMT(s) you are considering.

Key points

  • Numerous tests are carried out at the start of your treatment (baseline); these include blood, urine and tests for a range of infections.
  • Some patients will need tests or procedures specific to their DMT that are inappropriate for everyone with MS – for example, vaccination against some infections; pregnancy and/or genetic counselling; prevention of cardiovascular complications; and management of infusion reactions.
  • Ongoing monitoring is required for many but not all of the above factors.
  • All licensed MS DMTs have had a thorough risk ̶ benefit assessment, and their benefits are considered to outweigh the potential risks.

Standard tests … and why we do them

If you have read the article on immunosuppression, you will know that immunosuppressive DMTs may reduce white blood cell counts and antibody responses to vaccines and increase the likelihood of some infections and cancers. However, we can reduce the risk of many complications associated with long-term immunosuppression (we use the shorthand ‘de-risk’). This article explains what needs to be done at the start of DMT administration (baseline) and during subsequent monitoring. The specifics, however, vary from DMT to DMT.

Baseline tests

Tests at baseline (before starting DMT administration) include full blood count, platelets, liver, kidney and thyroid function tests, and a urine screen. Recording baseline immunoglobulin levels is particularly important if you are about to start an anti-CD20 therapy (ocrelizumab, ofatumumab or rituximab) so that we have a reference level for future comparisons. 

Serum protein electrophoresis is done for patients considering starting interferon-beta; having a so-called monoclonal gammopathy (an abnormal immunoglobulin) is a contraindication to starting an interferon-beta formulation in people with MS. The drug has been associated with a form of capillary leak syndrome, leading in rare cases to death from an adult respiratory distress syndrome.

The table below summarises the routine investigations required at baseline; subsequent sections provide further detail.

Tests routinely carried out at the start of treatment (baseline).
AHSCT, autologous haematopoietic stem cell transplantation; CMV, cytomegalovirus; CSF, cerebrospinal fluid; DMT, disease-modifying therapy; EBV, Epstein ̶ Barr virus; ECG, electrocardiogram; FBC, full blood count; HIV, human immunodeficiency virus; HPV, human papillomavirus; JCV, JC virus; LFTs, liver function tests; MMR, measles/mumps/rubella; MRI, magnetic resonance imaging; PCP, pneumocystis pneumonia; PML, progressive multifocal leukoencephalopathy; TB ELISpot, tuberculosis enzyme-linked immune absorbent spot; TFTs, thyroid function tests; U&E, urea and electrolytes; VZV, varicella zoster virus.

Infection screening

At our centre, we screen for a relatively large number of infectious diseases so that we can treat any subclinical infection before starting a DMT. This is particularly relevant for HIV-1 and 2, hepatitis B and C, syphilis and tuberculosis (TB).  

Screening for the JC virus (JCV), which causes progressive multifocal leukoencephalopathy (PML), is only really needed for people with MS considering starting natalizumab. Even if you are JCV positive, you can be treated with natalizumab for 6 ̶ 12 months and sometimes longer if you are prepared to take on the risk of PML and the extra monitoring required to detect PML early. 

We only check measles/mumps/rubella (MMR) status in patients without documentation of full vaccination as children. We check varicella zoster virus (VZV) status before starting immunosuppression and vaccinate seronegative individuals. Currently, we are still using the live VZV vaccine. This will change, and we will likely be offering all people with MS in the UK the component inactive VZV vaccine (Shingrix, that has had its licence extended) to reduce the chances of zoster reactivation in all adults starting immunosuppression. This new Shingrix indication is similar to the pneumococcal vaccine (Pneumovax). Our centre is only recommending Pneumovax in patients about to start an anti-CD20. However, when Shingrix becomes available on the NHS, it will make sense to bundle this with the Pneumovax and make it routine for all people with MS before starting immunosuppressive therapy. Please check with your healthcare team which products are available locally.

Routine tests and monitoring for Epstein-Barr virus (EBV) and cytomegalovirus (CMV) are only needed for subjects undergoing autologous haematopoietic stem cell transplantation (AHSCT), which causes profound short-term immunosuppression that can result in CMV and EBV reactivation. CMV reactivation also occurs with alemtuzumab, so this needs to be considered when investigating patients who develop complications after receiving alemtuzumab (please see Opportunistic infection in MS). 

For patients starting long-term immunosuppression, it is advisable to screen for active human papillomavirus (HPV) infection (by cervical smear or vaginal swab) and for warts or active infection with molluscum contagiosum. Warts are caused by HPV skin infection; molluscum contagiosum is due to a relatively benign pox virus that typically affects young children but occasionally affects adults. Warts and molluscum contagiosum can spread rapidly in patients receiving alemtuzumab, so I recommend treating these skin infections before starting immunosuppression for MS. 

Vaccinations

We encourage all patients to be vaccinated against COVID-19 and seasonal flu; outside the flu vaccine season, we remind people to get vaccinated during the next vaccine season. 

Hepatitis B, meningococcal and Haemophilus influenzae vaccines are considered only for people with MS who are at high risk of infection and have not had these vaccines as part of a national vaccine programme, i.e. healthcare and laboratory workers for hepatitis B, school and university students and military recruits for meningococcal vaccine and paediatric patients for Haemophilus influenzae

The issue around having the HPV vaccine as an adult is more complex. For example, in the UK, the NHS does not cover the cost of the vaccine for people over 25. In addition, most people have only had the quadrivalent vaccine (Gardasil-4), which covers about two-thirds of the strains that cause cancer. Some people with MS may want to upgrade their immunity with the polyvalent vaccine (Gardasil-9) that covers over 95% of the cancer-causing strains of HPV. For more information on HPV vaccination, please see Case study: cervical intraepithelial neoplasia (CIN) and ocrelizumab.

MMR is a live vaccine given in childhood (see MMR vaccine: to vaccinate or not? ). Owing to vaccine hesitancy, however, many people do not receive this vaccine as children. Therefore, if an adult with MS is about to start immunosuppressive therapy and has not been vaccinated against MMR, we advise them to do so. This is particularly important for people about to start natalizumab because these viruses are neurotropic and can infect the brain. Natalizumab blocks immune response within the brain; hence, exposure to a neurotropic virus could cause serious infection, similar to what we see with the JC virus – which causes PML.

Travel vaccines for people who travel as part of their work or plan to travel shortly need to be considered. In particular, the yellow fever vaccine is a live vaccine (made from a weakened yellow fever virus strain) and it should ideally be given before someone starts on immunosuppressive therapy. 

Cardiovascular screening

You may need an ECG (electrocardiogram), to rule out an abnormal heart rhythm or electrical conduction abnormality and to check your left ventricular function (ejection fraction). These abnormalities are a relative contraindication to using the S1P modulators (fingolimod, siponimod, ozanimod, ponesimod), which may affect the conduction of the heart. In patients treated with mitoxantrone, the left ventricular ejection fraction (LVEF) must be done at baseline and regularly monitored because mitoxantrone is toxic to the heart. If the LVEF drops significantly, further dosing of mitoxantrone is contraindicated. 

Pregnancy, family planning and genetic testing

Many chemotherapy agents used in AHSCT for ablating (extracting) the bone marrow are toxic to the ovaries and testes. Therefore, patients receive counselling before treatment and can have eggs (oocytes) or sperm banked for future use. Egg banking is also a consideration for women with MS being treated with mitoxantrone. Men receiving mitoxantrone do not need to bank sperm, however, because mitoxantrone does not cross the testes ̶ blood barrier. 

Genetic testing is only required at present if you wish to receive siponimod. Siponimod is metabolised by a specific liver enzyme (biological catalyst) with two functional variants – slow metabolising and fast metabolising. People who carry two slow-metabolising variants of the enzyme cannot receive siponimod. Intermediate metabolisers (those that carry one slow- and one fast-metabolising version of the enzyme) receive low-dose siponimod, while those with two fast-metabolising enzymes receive high-dose siponimod. 

Protecting against progressive multifocal leukoencephalopathy

I have included magnetic resonance imaging (MRI) and lumbar puncture with cerebrospinal fluid (CSF) testing for JCV among the baseline tests. This is specific to patients at high risk of developing PML who are switching from natalizumab to a depleting immune reconstitution therapy such as alemtuzumab or another therapy that depletes their immune system (e.g. cladribine or an anti-CD20 therapy). These tests are done to exclude asymptomatic PML, which will otherwise be carried over to the new treatment. The effects of these immunosuppressive therapies on your immune system cannot be rapidly reversed, which is a problem because immune reconstitution is needed to clear PML. Most MS centres do not mandate CSF testing in this situation because it does not always reveal the presence of PML. However, I still request this test on my patients to gain as much information as possible on which to base potentially life-changing decisions.

Prophylactic antivirals and antibiotics

Patients in our centre undergoing AHSCT or receiving alemtuzumab will be given antivirals and antibiotics to reduce the likelihood of certain infections. This is particularly relevant for listeriosis, which is a rare infection transmitted via food. We also encourage all our patients to start and maintain a specific diet to reduce the chances of listeriosis. The risk of listeriosis is only present for a short period when both the adaptive and innate immune systems are compromised, that is, for 4 weeks after receiving alemtuzumab, so we recommend antibiotic prophylaxis for 4 weeks. Our online resource provides more information about listeriosis. If you live in the UK, you can order our free listeriosis prevention kit, which contains a booklet (also downloadable) and various practical items to help keep you safe.

Strategies for limiting the risks from immune reconstitution therapies and infusion DMTs.

Infusion reactions

When you use agents that cause cell lysis (breakdown), such as alemtuzumab and intravenous anti-CD20 therapies, the contents of cells cause infusion reactions. To prevent such reactions or reduce their severity, we pretreat patients with corticosteroids, antihistamines and antipyretics. The exact protocols for each DMT differ; for example, ocrelizumab infusion reactions are generally only a problem with the first and second doses; therefore, many centres don’t give steroids with the third and subsequent infusions. The latter was particularly important during the COVID-19 pandemic when it was shown that the recent administration of high-dose steroids increased your chances of severe COVID-19. 

Ongoing monitoring

Once someone has been treated with a DMT, ongoing monitoring is required. What gets monitored and how frequently depends on the individual DMT. For a list of DMTs associated with important adverse events, please see our summary Table in ‘De-risking’ guide: monitoring requirements of individual DMTs.

The regulatory authorities usually put in place specific monitoring requirements, which can differ worldwide. It is important that you also enrol in your national cancer screening programmes. Being on chronic immunosuppression increases your chances of developing secondary malignancies, so please remain vigilant. 

Tests carried out regularly as part of ongoing monitoring.
FBC, full blood count; LFTs, liver function tests; MRI, magnetic resonance imaging; PML, progressive multifocal leukoencephalopathy; TFTs, thyroid function tests; U&E, urea and electrolytes.

I want to reassure you that all licensed MS DMTs have undergone a thorough risk ̶ benefit assessment by the drug regulators, and the benefits of these treatments are considered to outweigh the potential risks. On balance, the level of immunosuppression associated with MS DMTs is typically mild to moderate; hence, the complications are relatively uncommon. MS is a serious disease and, if left to run its natural course, would result in most patients becoming disabled. To learn more about the natural course of MS, please read the section entitled What are the consequences of not treating MS?