Medications for Musculoskeletal Disorders

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Medications for Musculoskeletal Disorders

• Unit 23

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Objectives

• State the actions, uses, type, usual dosage, and
  adverse reactions of selected neuromuscular
  blocking agents
• State the actions, uses, types, dosage, adverse
  reactions, implications for patient care, patient
  teaching, and special considerations for muscle
  relaxants
• Describe disease-modifying antirheumatic drugs

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Musculoskeletal System

• Composed of bones, muscles, ligaments, and
  tendons
• 206 bones
• Over 650 muscles
• Function maintain normal body posture and
  voluntary movement

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Muscle Contraction

• Each skeletal muscle is activated by a motor
  nerve that originates at the spinal cord and
  terminates in the muscle cells
• Neuromuscular junction point at which a motor
  nerve connects to a muscle cell
• Acetylcholine neurotransmitter that binds to
  receptor sites causing a muscle to contract

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Acetylcholinesterase

• Following contraction, this enzyme destroys
  acetylcholine and prepares muscle fibers to
  receive the next nerve impulse.

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Benefits of Exercise

• Reduces risk of heart disease
• Reduces the level of triglycerides
• Strengthens muscles
• Keeps joints, tendons, and ligaments more flexible

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Anti-Inflammatory Drugs

• Inflammation bodys normal response to injury,
  infection, or irritation of living tissues.
• Characteristics of the inflammatory process
  include redness, tenderness, pain, and swelling
  at the affected site of injury

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Anti-Inflammatory Agents

• Drugs that relieve the symptoms and pain
  associated with inflammation
• Steroidal anti-inflammatory agents aka
  corticosteroids, can be applied to the skin for
  topical treatment or injected into a specific
  joint to reduce the effects of inflammation

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Corticosteroids (Glucocorticoids)

• Actions anti-inflammatory effects in disorders
  of many organ systems
• Uses rheumatoid arthritis, bursitis,
  osteoarthritis
• Adverse reactions fluid retention, CHF, muscle
  weakness, poor wound healing, petechiae

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Non-steroidal anti-inflammatory drugs (NSAIDS)

• Synthetic products that are unrelated to any
  natural substance produced by the body
• Actions result from the inhibition of
  prostaglandin synthesis
• Adverse reactions N/V, gastric ulcers,
  gastrointestinal bleeding

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Common NSAIDS

• Aspirin (Acetylsalicylic acid)
• Motrin (Ibuprofen)
• Aleve (naproxen sodium)
• Ketorolac (Toradol)

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Disease-Modifying Antirheumatic Drugs (DMARDs)

• Reduce pain, improve stiffness and mobility in
  patients with rheumatoid arthritis do NOT slow
  the progression of joint damage
• Gold used in long-term treatment of rheumatoid
  arthritis effective in reducing the progression
  of the disease
• Gold therapy (chrysotherapy) can be toxic

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Other DMARDs

• Penicillamine
• Rheumatrex
• Both have been used in the treatment of
  rheumatoid arthritis. May cause hepatotoxicity
  and jaundice

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Cox-2 Inhibitors

• New class of drugs approved for use in the
  treatment of osteoarthritis
• Ex. Celebrex and Mobic
• Cyclooxygenase (COX) is an enzyme involved in
  normal cellular function and the inflammatory
  response
• COX-2 found in joints inhibition reduces
  inflammation and pain

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Anti-Tumor Necrosis Factor Drugs

• Drugs that slow the destruction of the joints by
  disrupting the activity of tumor necrosis factor
  (TNF), which is an integral part of the immune
  response.
• Autoimmune response bodys defense system
  malfunctions and begins to attack itself
• Ex Lupus, rheumatoid arthritis

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Gout

• Hereditary metabolic disease that is a form of
  acute arthritis.
• Marked by inflammation of the joints and usually
  begins in the knee or foot
• Caused by excessive uric acid in the blood which
  deposit in and around the joints

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Skeletal Muscle Relaxants

• Used to treat painful muscle spasms resulting
  from injuries
• Muscle spasm involuntary contraction of one or
  more muscles accompanied by pain and limitation
  of function
• Depress the CNS cause a sedative effect

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Neuromuscular Blocking Agents

• Used to provide muscle relaxation and to reduce
  the need for deep general anesthesia in surgery
• Two types
• 1. Competitive compete with acetylcholine for
  receptor sites preventing muscle stimulation
  causing paralysis of the muscle fibers

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Neuromuscular Blocking Agents

• 2. Depolarizing mimic the action of
  acetylcholine, but they are not destroyed by
  cholinesterase, so they cause a long-term state
  of paralysis

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Skeletal Muscle Stimulants

• Inhibit the action of acetylcholinesterase, the
  enzyme that halts the action of acetylcholine at
  the neuromuscular junction