Introduction
Methodology
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gMG adult patients with specific considerations based on the autoimmune antibodies (AChR + , LRP4 positive (LRP4 +), MuSK positive (MuSK +), or seronegative),
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oMG,
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(Impending and manifesting) myasthenic crisis.
Recommendations for treatment
MG treatment strategy
Symptomatic treatment
Medication | Start dose | Maintenance dose | Action onset | Frequently reported side effects | Prevention of side effects |
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Symptomatic treatment | |||||
Pyridostigmine ! CI in patients with mechanical obstruction of the intestines or urinary tracts! | 30 mg; 1–3dd | 30–90 mg; 3-6dd (max 720 mg dd and max 120 mg per intake) | 30–45 min | Hyperhidrosis, sialorrhea, epiphora, nausea, diarrhoea, polyuria, fasciculations, muscle cramp | Consider cardiac evaluation prior to initiation of pyridostigmine. Reduce dose in case of reduced kidney functioning |
Immunosuppressive treatment | |||||
Corticosteroids ! CI in patients with ocular herpes simplex ! | 32–64 mg methylprednisolone dd (40–80 mg prednisolone dd) | 32–64 mg methylprednisolone (40–80 mg prednisolone), followed by slow tapering to lowest possible dose | 4–8 weeks | Hypertension, hyperglycaemia, weight gain, osteoporosis, skin atrophy, cardiovascular disease, dyslipidaemia, cataract, glaucoma, increased infection risk, irritability, initial worsening of symptoms, steroid myopathy | Blood pressure and glycaemic and lipid control, follow-up and treatment if needed. Bone loss prevention. Slow initiation in patients with bulbar/respiratory complaints. Optimize vaccination status, live (attenuated) vaccinations preferably before starting treatment. Avoid grapefruit (juice) |
Azathioprine !Treatment with allopurinol is a CI! | 50 mg dd | 2–3 mg/kg/dd, by increasing 50 mg every 2–4 weeks | 6–12 months | Nausea, diarrhoea, fever, muscle and bone pain, fatigue, rash, hair loss, leukopenia, thrombocytopenia, skin tumours | CBC, liver function, reduce exposure to direct sunlight, use of highly protective sun blockers, TPMT assessment prior to initiation. Optimize vaccination status, live (attenuated) vaccinations preferably before starting treatment |
Mycophenolate Mofetil ! Pregnancy is CI! | 250–500 mg; 2 dd | Increase weekly with 500 mg until 1000 mg; 2 dd | 3–4 months | Infections, leukopenia, anaemia, thrombopenia, hypercholesterolaemia, hyperglycaemia, alkalosis, hyperphosphatemia, confusion, depression, sleep disturbances, anxiety, dizziness, headache, hypertension, diarrhoea, nausea, emesis, constipation | Reduce exposure to direct sunlight, use of highly protective sun blockers, CBC and liver function monitoring. Optimize vaccination status, live (attenuated) vaccinations preferably before starting treatment |
Tacrolimus | 3 mg dd or 0.1 mg/kg/dd | 3 mg dd or 0.1 mg/kg/dd | 2–3 months | Nephrotoxicity, lymphoma, skin cancer, anaemia, leukopenia, thrombocytopenia, hyperglycaemia, alkalosis, sleep disturbances, tremor, headache, hepatotoxicity, rash, dyspnoea, hypertension, diarrhoea, nausea, nephrotoxicity | Reduce exposure to direct sunlight, use of highly protective sun blockers, BP and kidney function monitoring. Avoid St John’s wort. Optimize vaccination status, live (attenuated) vaccinations preferably before starting treatment |
Cyclosporine | 25–100 mg 2dd | 3–6 mg/kg/dd in 2 doses (through level < 300 ng/ml in blood) | 1–3 months | Nephrotoxicity, tremor, hirsutism, hypertension, diarrhoea, anorexia, nausea, emesis, leukopenia, hyperlipaemia, hepatotoxicity | BP, kidney and liver function monitoring, CBC, reduce exposure to direct sunlight, use of highly protective sun blockers. Avoid St John’s wort. Optimize vaccination status, live (attenuated) vaccinations preferably before starting treatment |
Advanced therapies | |||||
Rituximab | Refer to NMRC | Multiple initiation and maintenance schemes used | 8–16 weeks | Progressive multifocal leukoencephalopathy (PML), infections, infusion reactions, nausea, rash, pruritus, fever, headache, neutropenia, leukopenia, reactivation risk for hepatitis B and tuberculosis | CBC, kidney and liver function monitoring. Optimize vaccination status, live (attenuated) vaccinations preferably before starting treatment. Check hepatitis B and tuberculosis status prior to treatment |
Eculizumab | Refer to NMRC 900 mg | 900 mg weekly for 4 weeks, 1200 mg at week 5, from then on 1200 mg biweekly | 2–12 weeks | Pneumonia, UTI, leukopenia, anaemia, sleeping disturbances, hypertension, dizziness, URTI, diarrhoea, nausea, emesis, joint and muscle pain, fever, infusion reactions | Optimize vaccination status, live (attenuated) vaccinations preferably before starting treatment [27].Obligatory meningococcal vaccination before start |
Efgartigimod | Refer to NMRC 10 mg/kg | 10 mg/kg, treatment cycles of 4 weeks, with IV infusions once weekly | 1–4 weeks | URTI, UTI, myalgia, headache during administration, nasopharyngitis | Optimize vaccination status, live (attenuated) vaccinations preferably before starting treatment |
Immunosuppressive therapies
Advanced therapies
Generalized MG
Presence of thymoma or thymic enlargement
AChR +
LRP4 + and seronegative Ab gMG
MuSK +
Ocular MG
Impending and manifesting myasthenic crisis
Other considerations
Comorbidities
Drugs that induce or cause deterioration of MG
Pregnancy
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Thymectomy should be considered prior to pregnancy or postponed until after pregnancy [16].
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Plasmapheresis can be used in case of exacerbations or when intensified therapy is needed.