Musculoskeletal drugs Flashcards
alendronate (Fosamax)
Class: Biphosphonates
MoA: Inhibits Ca+ resorption from bone by decreasing the activity of osteoclasts
Use: Osteoporosis and Paget’s disease. May also be used in children w poor bone calcification/osteopenia, and in pts with bone cancer.
Admin: PO, in morning on empty stomach, 30 mins before food. Remain upright 30 mins after admin to prevent esophageal irritation
AEs: Minor if taken as directed. If dose too high, risk for esophageal erosion, dysphagia, HA, musculoskeletal pain, decreased Ca+ levels. Rare side effects w long term use: ocular inflammation, osteonecrosis of jaw and atypical femur fractures.
Considerations: Do not use in pts w severe renal impairment. Interactions: ASA and NSAIDs increase risk for GI effects. Antacids and Ca+ supplements interferes with absorption if taken w/in 2 h.
raloxifene (Evista)
Class: Selective estrogen receptor modulators
MoA: Binds to estrogen receptors and mimics effects of estrogen on bone (decr. proliferation of osteoclasts & decr. bone resorption), lipid metabolism (lowers LDL), and blood clotting (incr. r/f thromboembolism). Blocks estrogen effects in breast tissue and endometrium to decr. risk for cancers in these areas.
Use: Post-menopausal osteoporosis. May offer protection against breast and endometrial cancer.
Admin: PO 60mg daily. Wear gloves when handling.
AEs: Increased risk for thromboembolic events (stroke, MI, PE, DVT)
Considerations: Cholestyramine decreases absorption. Avoid taking w estrogen HRT. Avoid with warfarin.
baclofen (Gablofen, Lioresal)
Class: Gamma-Aminobutyric Acid derivatives
MoA: Centrally acting muscle relaxer. Reduces influx of Ca+ to reduce presynaptic neurotransmitter release in excitatory pathways in spinal neurons. Results in reduced impulse transmission from spinal cord to skeletal muscles and this reduces muscle spasms. Suppresses hyperactive reflexes.
Use: Relieve spasms related to multiple sclerosis and some spinal cord injuries.
Considerations: Abrupt discontinuation a/w hallucinations, paranoia, seizures. OD can produce coma, resp depression. May exacerbate psychosis in schizophrenia.
AEs: drowsiness, dizziness, weakness, fatigue, confusion, HA, insomnia, hypotension, N/V, constipation, urinary frequency, may increase BG.
cyclobenzaprine (Flexeril)
Class: Tricyclic antidepressant derivative: centrally acting muscle relaxer
MoA: Appears to act in brain stem and spinal cord reducing tonic motor activity resulting in relaxation of muscle.
Uses: 1st choice for acute localized muscle spasm. Relief of muscle spasms and associated pain, in conjunction with other therapies like PT & Heat. Ineffective for spasticity.
Considerations: Contraindicated with MAOIs, SSRIs, SNRIs & tricyclic antidepressants–all increase r/f serotonin syndrome. BEERS criteria drug.
AEs: CNS depressant: drowsiness, dizziness, fatigue. Anticholinergic effects: dry mouth, blurred vision, photophobia, urinary retention & constipation. Cardiac rhythm disturbances.
