Musculoskeletal Pharmacology

1. Musculoskeletal Pharmacology Jennifer Kean MSN, RN, CCRN

2. Disease-modifying antirheumatic drugs (DMARDS) • Treat conditions such as rheumatoid arthritis, systemic lupus erythematosus, fibromyalgia, gout • Include methotrexate, hydroxychloroquine, sulfasalazine, etanercept, adalimumab, rituximab, abatacept • Also used to treat: glucocorticoids- Prednisone and prednisolone • And, NSAIDS: aspirin, ibuprofen, diclofenac, indomethacin, naproxen, celecoxib • Act to slow joint degeneration and progression of rheumatoid arthritis, relieve inflammation, and relieve pain • Used to treat joint pain & swelling, slow/delay worsening of the disease, maintain joint function

3. Complications • Increased risk of infection, hepatic fibrosis and toxicity, bone marrow suppression, ulcers in the mouth and/or stomach. Fetal death/congenital abnormalities • Also proteinuria from renal toxicity, thrombocytopenia, agranulocytosis, hepatitis, GI discomfort, retinal damage/blindness, subcutaneous sit injection reactions, IV infusion reactions, heart failure, osteoporosis, fluid retention, hyperglycemia • Contraindicated in pregnancy/breastfeeding, liver or renal dysfunction, cancer/bone marrow suppression, heart failure, any type of active infection • Interactions: live vaccines, PCN (toxicity), concurrent use of antiseizure meds (reduce effectiveness), insulin and oral diabetic meds (reduce effectiveness)

4. Pregabalin (GABA analogue) • Used primarily to treat fibromyalgia, seizures, neuropathic pain • Restores balance of neurotransmitters serotonin and norepinephrine • Complications include drowsiness, fatigue, blurred vision, lightheadedness, increased appetite, weight gain, angioedema (indicates allergy), erectile dysfunction and anorgasmia • Contraindicated in pregnancy/breastfeeding • Use with caution in older adults, patients with cardiac problems, hypertension, diabetes, renal dysfunction, mental illness • Interactions: benzodiazepines (increase drowsiness), alcohol (increases drowsiness and dizziness) • Give with or without food, notify provider of any suicidal thoughts, taper gradually

5. Meds for gout (hyperuricemia) • Allopurinol, probenecid, colchicine • Act by inhibiting uric acid production • Colchicine is only used for those who don’t respond well to allopurinol or probenecid • Complications: mild GI distress, thrombocytopenia, bone marrow suppression, sudden onset of muscle pain, renal calculi, rash, hepato- and nephrotoxicity • Contraindicated in pregnancy/breastfeeding, severe kidney or cardiac problems; do not give within 2 weeks of an acute gout attack • Interactions: grapefruit juice can increase adverse effects, salicylates can lessen effectiveness, allopurinol slows the metabolism of warfarin, leading to toxicity

6. Biphosphenates • Include alendronate, ibandronate, risendronate • Increase the number and action of osteoclasts and inhibit bone resorption • Used to treat postmenopausal osteoporosis or osteoporosis due to long-term corticosteroid use • Complications include esophagitis and esophageal ulceration, GI upset, musculoskeletal pain, visual disturbances, necrosis of jaw (with IV infusion) • Contraindicated in pregnancy, patients with dysphagia or known GI problems, patients who cannot sit upright or stand upright for 30 minutes after administration • Absorption decreases when taken with calcium, iron, Mg supplements, antacids, orange juice and caffeine