29 Drugs Used to Treat Musculoskeletal Conditions

Multimedia Directory Slide 6 Osteoporosis Video Slide 25 Arthritis Video Slide 38 Mechanism of Action of Methotrexate Animation

Figure 29-1 The skeletal system and its functions.

Calcium Most abundant mineral in body Proper balance and interaction with other minerals and hormones is essential to optimal function of several body system. Typical body has 1–2 kg of calcium, 99% of which is in bones.

Osteoporosis Bones become thinner and weaker during aging: osteopenia Osteoporosis: bone mass is reduced enough to cause abnormal functioning Increased incidence of fracture Occurs more often in women than men, often in postmenopausal women because of reduced estrogen levels

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Table 29-1 Drugs Used to Treat Osteoporosis

Bisphosphonates: Uses Highly selective inhibitor of bone demineralization and resorption; appears to increase bone density Used to treat osteoporosis; some for Paget’s disease; some for hypercalcemia of malignancy; some for postmenopausal osteoarthritis

Bisphosphonates: Adverse Effects Bisphosphonates commonly cause various GI upsets, including: Flatulence Acid regurgitation Dysphagia Gastritis

Bisphosphonates: Adverse Effects (conditions) Other adverse effects include: Headache Musculoskeletal pain Rash

Bisphosphonates: Contraindications Contraindicated in severe renal impairment, hypocalcemia, lactation, pregnancy Used cautiously in patients with congestive heart failure, hypophosphatemia, liver disease, fever or infection, peptic ulcer

Bisphosphonates: Patient Information Review the correct administration with patients. Advise patients to report fever accompanied by arthralgia and myalgia. Instruct patients to take 30 minutes before food, beverages, or other medications.

Calcitonin: Uses Derived from salmon, lowers serum calcium and phosphate levels by action on bones and kidneys; inhibits bone resorption, thereby increasing bone density Used to treat osteoporosis in postmenopausal women, hypercalcemia, and symptomatic Paget’s disease

Calcitonin: Adverse Effects Headache Eye pain Anaphylaxis (reported for human calcitonin only) Urinary frequency Chills

Calcitonin: Adverse Effects Chest pressure Weakness Nasal congestion Shortness of breath

Calcitonin: Contraindications Avoid in patients with history of allergy (especially to fish) Safe use in children, pregnancy, and lactation not established Cautious use in patients with renal impairment or pernicious anemia

Calcitonin: Patient Information Advise patients to report redness, warmth, or swelling at injection site. Instruct patients to check with physician before taking OTC preparations such as supervitamins and antacids.

DMSO Dimethyl sulfoxide, known as DMSO, is a topical agent that can help reduce pain and inflammation in various musculoskeletal disorders. Only use under a physician’s guidance.

Raloxifene (Evista): Uses A selective estrogen-receptor modulator (SERM); acts by combining with estrogen receptors to decrease bone resorption and increase bone mass and density Used to prevent and treat osteoporosis and to reduce risk of breast cancer in postmenopausal women

Raloxifene: Adverse Effects Hot flashes Migraines and other types of headache Flu-like symptoms Vaginal bleeding Uterine and urinary tract disorders

Raloxifene: Adverse Effects Breast pain Depression Insomnia Dizziness

Raloxifene: Contraindications Contraindicated in women who may become pregnant and in those with venous thromboembolic disease Not to be used with systemic estrogen replacement therapy Should be used cautiously with diazepam, lidocaine, and diazoxide

Raloxifene: Patient Information Advise patients to report unexplained calf pain or tenderness. Instruct patients to avoid prolonged restriction of movement during travel.

Rheumatoid Arthritis (RA) Systemic autoimmune disease that involves inflammation of joint-lining membranes; also affects internal organs Occurs 2–3 times more often in women (onset usually at ages 40–60) Joints affected include hands, feet, wrists, spine, shoulders, ankles, and hips

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Table 29-2 Disease-Modifying Drugs for Rheumatoid Arthritis

Table 29-2 (continued) Disease-Modifying Drugs for Rheumatoid Arthritis

Gold Compounds: Uses Mechanism of action not clearly understood Used to treat active RA

Gold Compounds: Adverse Effects Common: syncope, bradycardia, thickening of tongue, metallic taste in mouth Serious: thrombocytopenia, leukopenia, aplastic anemia

Gold Compounds: Contraindications Uncontrolled diabetes Renal or hepatic insufficiency Hepatitis

Gold Compounds: Patient Information Instruct patients to report adverse effects. Advise patient to report unusual color or odor of urine, and to avoid contact with anyone who has a cold, has had a recent vaccination, or has been exposed to a communicable disease.

Hydroxychloroquine (Plaquenil): Uses Mechanism of action unclear Used to treat RA and systemic lupus erythematosus

Hydroxychloroquine: Adverse Effects Common: fatigue, headache, mood or mental changes, anxiety, difficulty focusing or blurred vision, anorexia, nausea and vomiting, abdominal cramps Serious: retinopathy

Hydroxychloroquine: Contraindications Safety in pregnancy and lactation not established. Cautious use in patients with hepatic disease, alcoholism, impaired renal function

Hydroxychloroquine: Patient Information Advise patients to follow drug regimen exactly as prescribed and to keep drug out of reach of children. Instruct patients to get regular eye exams. Instruct patients to avoid breast feeding.

Hydroxychloroquine Acute or chronic diseases that affect liver architecture or function also affect hepatic metabolism of some drugs. Elderly patients may therefore have markedly affected drug elimination and need dosage adjustment.

Methotrexate (Folex, Mexate): Uses Folic-acid blocker and immunosuppressant that affects lymphocyte and macrophage function Used to treat severe psoriasis, psoriatic arthritis, and RA; also to maintain remission in neoplastic disease

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Methotrexate: Adverse Effects Common: GI upset and mouth sores, amenorrhea Serious: bone-marrow suppression, infertility

Methotrexate: Contraindications Contraindicated in: pregnancy and lactation, men and women of childbearing age, hepatic and renal insufficiency, preexisting blood dyscrasias Cautious use in patients with infections, peptic ulcer, colitis, poor nutritional status

Methotrexate: Patient Information Advise patients of the dangers of this drug and explain symptoms to immediately report. Warn patients to avoid alcohol. Tell patients to avoid sunlight and UV light and to wear sunglasses.

Methotrexate Prolonged use of small doses can lead to hepatotoxicity.

Sulfasalazine (Azulfidine): Uses Locally acting sulfonamide that may exert an anti-inflammatory effect Used to treat RA, juvenile chronic arthritis, and ankylosing spondylitis

Sulfasalazine: Adverse Effects Common: nausea, vomiting, headache, rash Serious: anemia, oligospermia, blood dyscrasias, liver injury, allergic reactions

Sulfasalazine: Contraindications Contraindicated in patients with agranulocytosis, intestinal and urinary tract obstruction, or porphyria; pregnancy and lactation Cautious use in severe allergy or bronchial asthma, hepatic or renal impairment, or in children younger than 6 years

Sulfasalazine: Patient Information Instruct patients that urine and skin may turn orange-yellow. Women should not breast feed.

Gout and Gouty Arthritis Characterized by crystal deposits in and around joint spaces, leading to acute inflammation of joint Gout commonly affects men after age 50. Three manifestations: hyperuricemia, acute gouty arthritis, chronic gouty arthritis

Table 29-3 Anti-Gout Medications

Colchicine: Uses Uses: anti-inflammatory agent used to treat gout; inhibits formation of white blood cells Adverse effects: Common: GI disturbances decreased absorption of vitamin B12 Contraindications: severe cardiac, renal, hepatic, blood, and GI diseases

Colchicine: Uses Patient education: Advise patients to report severe GI symptoms or signs of bone-marrow depression.

Colchicine in Elderly Patients Colchicine must be used cautiously in elderly patients because of its possible adverse GI, cardiac, renal, and hepatic effects.

Allopurinol (Aloprim): Uses Improves solubility of uric acid; used to control chronic, not acute, gout

Allopurinol: Adverse Effects Common: drowsiness, headache, dizziness, nausea and vomiting, abdominal pain Serious: hepatotoxicity, renal insufficiency

Allopurinol: Contraindications Contraindicated children (except in those with hyperuricemia secondary to cancer and chemotherapy) Safety in pregnancy and lactation not established. Cautious use in patients with impaired hepatic or renal function, history of peptic ulcer, lower GI tract disease, and bone-marrow suppression

Allopurinol: Patient Information Advise patients to drink 3 quarts of fluid per day. Instruct patients to report diminishing urine output, cloudy urine, unusual color or odor to urine, pain or discomfort during urination, itching and rash. Patients should avoid driving and sun exposure.

Uricosuric Agents: Uses Competitively inhibit renal tubular reabsorption of uric acid to promote its excretion Used to treat severe attacks of gout

Uricosuric Agents: Adverse Effects GI irritation Allergic dermatitis Nephrotic syndrome

Uricosuric Agents: Contraindications Contraindicated in patients with blood dyscrasias and uric-acid kidney stone Safety in pregnancy, lactation, or in children younger than 2 years not established. Cautious use in patients with peptic ulcer

Uricosuric Acid: Patient Information Advise patients to drink 3 quarts of fluid per day. Physicians may advise patients to restrict intake of high-purine foods (organ meats, meat soups, and gravy).

Uricosuric Acid: Patient Information Instruct patients to not stop treatment, or not to take aspirin or OTC medications without consulting physician.

Muscle Spasms and Pain Often associated with traumatic injuries and spasticity from disorders such as cerebral palsy, stroke, or head and spinal cord injuries Two types of muscle spasms: tonic and clonic

Table 29-4 Centrally Acting Muscle Relaxants

Table 29-4 (continued) Centrally Acting Muscle Relaxants

Centrally Acting Skeletal Muscle Relaxants Uses: treat local spasms to reduce pain and increase range of motion Adverse effects: sedation, weakness, fatigue Contraindications: some contraindicated in liver disease, porphyria, children, pregnancy, lactation

Centrally Acting Skeletal Muscle Relaxants Patient information: avoid alcohol, other CNS depressants. Patients with diabetes must closely monitor glucose levels.