IV Therapy Musculoskeletal drugs

Disease-Modifying Anti-Rheumatic Drugs (DMARDs)

• Slow joint degeneration and progression of rheumatoid arthritis (RA).
• Used when pain relief and anti-inflammatory drugs are ineffective.
• Act by producing immunosuppression; also treat fibromyalgia and inflammatory bowel diseases (Crohn's disease).
• Common adverse reactions: Nausea, stomatitis, alopecia.
• Other potential adverse reactions: Skin rash, fever, easy bruising, visual changes, tinnitus, hearing loss.
• Sulfasalazine-containing DMARDs: Ocular changes, gastrointestinal upset, mild pancytopenia.
• Plaquenil: Can cause retinal damage.
• Contraindications (Methotrexate): Renal insufficiency, liver disease, alcohol abuse, folate deficiency, pancytopenia.
• Contraindications (Enbrel, Humira, Remicade): Heart failure (HF) or neurological demyelinating diseases.
• Late-stage RA deformities: Boutonniere deformity of the thumb, ulnar deviation of metacarpophalangeal joints, swan-neck deformity of fingers.
• Precautions: Pregnancy and drug transmission to semen (barrier methods).
• Methotrexate precautions: Monitor thrombocytopenia, leukopenia, liver, and kidney functions every 3 months.
• Reporting issues: Report mouth sores, diarrhea, fever, sore throat, easy bruising, rash, itching, or nausea/vomiting.
• Drug interactions (DMARDs):
  • Sulfa drugs increase methotrexate toxicity.
  • Aspirin and NSAIDs increase methotrexate toxicity.
• Nursing Interventions: Monitor labs (thrombocytopenia, leukopenia, liver enzymes, kidney function). Monitor for drug toxicity. Teach patient compliance, birth control, reporting of infections/bleeding/allergies.

Bone Resorption Inhibitors (Bisphosphonates)

• Inhibit bone resorption, increasing bone density and reversing osteoporosis.

• Used for osteoporosis in postmenopausal women and in hypercalcemia of malignancy.

• No completely safe drug: No drug is risk-free.

• Adverse reactions:

  • Increased/recurrent bone pain.
  • Esophagitis, esophageal ulceration, dyspepsia, acid regurgitation, dysphagia.
  • Abdominal pain, nausea, diarrhea, constipation.
  • Musculoskeletal pain.
  • Visual disturbances.
  • Increased risk of bleeding (especially with other clotting inhibitors).
  • Nephrotoxicity (IV infusions).

• Contraindications: Pregnancy, lactation, hypocalcemia, dysphagia, esophageal stricture, serious kidney impairment. Fosamax and Actonel in patients with hypocalcemia.

• Drug interactions:

  • Antacids decrease bisphosphonate effectiveness.
  • Aspirin increases risk of GI bleeds.
  • Theophylline increases Theophylline toxicity.
  • Caffeine, orange juice, magnesium supplements, iron, and calcium decrease alendronate absorption (wait 2 hours).

• Nursing Interventions: Administer with 8 oz water, upright position, stay upright 30 minutes after. Take first thing in the morning on an empty stomach. Supplement calcium and vitamin D if needed. Regular bone scans (12-18 months). Monitor blood calcium. Exercise (30-40 minutes daily).

Uric Acid Inhibitors

• Used for acute gout attacks (colchicine); preventing attacks (allopurinol, probenecid, febuxostat).

• Adverse reactions: Nausea, vomiting, diarrhea (all drugs).

• Allopurinol: Skin rash, hepatitis, kidney damage.

• Colchicine: Severe nausea, vomiting, bone marrow depression, thrombocytopenia, rhabdomyolysis.

• Probenecid: Kidney stones, kidney problems.

• Contraindications: Pregnancy, lactation.

• Anturane (sulfinpyrazone): Peptic ulcer disease.

• Colchicine: Serious GI, renal, hepatic, or cardiac disorders.

• Probenecid: Blood dyscrasias, uric acid kidney stones, children under 2 years.

• Drug interactions:

  • Grapefruit juice increases colchicine side effects.
  • Ampicillin may cause rash with allopurinol.
  • Theophylline increases allopurinol toxicity.
  • Coumadin increases allopurinol bleeding risk.
  • Penicillin increases antibiotic levels with probenecid.
  • NSAIDs increase NSAID levels with probenecid.
  • Barbiturates increase sedation with probenecid.
  • Salicylates decrease probenecid effectiveness.

Oral anticoagulants increase bleeding risk with Anturane. Tobutamide increases hypoglycemia risk with Anturane.

• Nursing Interventions: Take with meals/plenty of water (3000 cc/day). Maintain adequate urine. Monitor stool and urine for blood. Keep colchicine on hand. Monitor uric acid levels, CBC, UA, liver, and kidney function. Stop drug and notify provider if rash develops. Avoid alcohol and high-purine foods. Regular exercise.

Skeletal Muscle Relaxants

• Uses: For acute musculoskeletal pain.

• Adverse Reactions (all): Drowsiness, dizziness, UTI (Zanaflex). Some drugs include hepatic toxicity; chronic use may lead to physical dependence.

• Baclofen: Nausea, constipation, urinary retention, seizures.

• Dantrolene: Hepatic toxicity, muscle weakness.

• Contraindications: Pregnancy, lactation.

• Flexeril & MAOIs: Avoid within 14 days of MAOI use.

• Flexeril: Recent MI, cardiac conduction problems, or hyperthyroidism.

• Diazepam: Controlled substance (IV use).

• Drug Interactions: CNS depressants increase CNS depressant effects. Flexeril and MAOIs increase risk of seizures/fever. Norflex and Haldol increase psychosis risk. Zanaflex and antihypertensives increase hypotension risk.

• Nursing Interventions: Take with or after meals to minimize GI problems. Short-term use only (2-3 weeks). Avoid alcohol/CNS depressants.