Levothyroxine is also contraindicated for people with uncorrected adrenal insufficiency, as thyroid hormones may cause an acute adrenal crisis by increasing the metabolic clearance of glucocorticoids. For oral tablets, the inability to swallow capsules is an additional contraindication. Side effects
Adverse events are generally caused by incorrect dosing. Long-term suppression of TSH values below normal values frequently cause cardiac side effects and contribute to decreases in bone mineral density (low TSH levels are also well known to contribute to osteoporosis).Too high a dose of levothyroxine causes hyperthyroidism. Overdose can result in heart palpitations, abdominal pain, nausea, anxiousness, confusion, agitation, insomnia, weight loss, and increased appetite. Allergic reactions to the drug are characterized by symptoms such as difficulty breathing, shortness of breath, or swelling of the face and tongue. Acute overdose may cause fever, hypoglycemia, heart failure, coma, and unrecognized adrenal insufficiency. Acute massive overdose may be life-threatening; treatment should be symptomatic and supportive. Massive overdose can be associated with increased sympathetic activity, thus may require treatment with beta-blockers.The effects of overdosing appear 6 hours to 11 days after ingestion. Interactions
Many foods and other substances  can interfere with absorption of thyroxine. Substances that reduce absorption are aluminium- and magnesium-containing antacids, simethicone, sucralfate, cholestyramine, colestipol, and polystyrene sulfonate. Sevelamer with calcium carbonate may decrease the bioavailability of levothyroxine. Grapefruit juice may delay the absorption of levothyroxine, but based on a study of 10 healthy people aged 20–30 (eight men, two women), it may not have a significant effect on bioavailability in young adults.
Birnkrant DJ, Bushby K, Bann CM, Alman BA, Apkon SD, Blackwell A,  et al. (April 2018). "Diagnosis and management of Duchenne muscular dystrophy, part 2: respiratory, cardiac, bone health, and orthopaedic management". Lancet Neurol. 17 (4): 347–361. doi:10.1016/S1474-4422(18)30025-5. PMC 5889091. PMID 29395990. External links

Muscular Dystrophies at Curlie
CDCs National Center on Birth Defects and Developmental Disabilities (previously listed below as "Duchenne/Becker Muscular Dystrophy, NCBDDD") at CDC
Genes and Disease Page at NCBI