Endocrine and Musculoskeletal Drugs
Thyroid, corticosteroids, gout and bone
Levothyroxine
- Same time daily on an empty stomach, 30–60 min before breakfast, with water.
- Separate from calcium, iron, antacids and binders by 4 h. Long-term PPIs can lower absorption (check TSH).
- TSH is rechecked after 6–8 weeks; dose changes take that long to show.
- Too much = hyperthyroid signs: palpitations, tachycardia, insomnia, weight loss, heat intolerance.
- Older adults and heart disease: start low, go slow. Dose usually increases in pregnancy. Lifelong.
Antithyroid drugs
- Methimazole is first-line for hyperthyroidism.
- PTU is used in the first trimester of pregnancy and in thyroid storm. It carries a boxed warning for severe liver injury.
- Both cross the placenta. PTU is preferred in the first trimester because methimazole can cause birth defects then; switching to methimazole afterwards may be considered (PTU liver risk).
- Both: agranulocytosis: report sore throat and fever immediately (check WBC).
- Others: beta blockers for symptoms; iodine before surgery; radioactive iodine (not in pregnancy or breastfeeding; distance and hygiene precautions).
Long-term corticosteroids (prednisone, hydrocortisone, dexamethasone)
- ↑ glucose, ↑ BP, fluid retention, weight gain, moon face
- Infection risk and masked signs of infection
- Osteoporosis (calcium, vitamin D, bone density), cataracts, glaucoma
- Stomach irritation (take with food), thin skin, poor wound healing
- Mood changes, insomnia
- Never stop suddenly after more than ~2–3 weeks: taper (risk of adrenal crisis).
- Extra "stress dosing" may be needed during illness or surgery: per prescriber.
- Take in the morning (mimics the body's rhythm).
- Avoid live vaccines on high doses.
Gout
- Acute flare: NSAIDs, colchicine (diarrhea is a toxicity sign; lower doses now used), or steroids.
- Prevention (lower uric acid): allopurinol (first-line), febuxostat. Allopurinol can be started during a flare with anti-inflammatory cover. Stop and report any rash (SJS); HLA-B*5801 testing for some ancestries.
- Fluids 2–3 L/day; limit alcohol (especially beer), organ meats, shellfish, sugary drinks.
Osteoporosis
- Bisphosphonates (alendronate, risedronate): first thing in the morning with a full glass of plain water, empty stomach, stay upright 30 min before food or other drugs (esophagitis). Rare jaw osteonecrosis (dental check) and thigh fractures.
- Denosumab: injection every 6 months; low calcium; don't stop without a plan (rebound spine fractures).
- Anabolic: teriparatide, abaloparatide, romosozumab (heart risk).
- Calcium + vitamin D; weight-bearing exercise; fall prevention.