Respiratory System Drugs

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Respiratory System Drugs

• Antitubercular Drugs

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Antitubercular Drugs

• Tuberculosis (TB)
• Caused by Mycobacterium tuberculosis
• Antitubercular drugs treat all forms of
  Mycobacterium

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Antitubercular DrugsMycobacterium Infections

• Common infection sites
• Lung (primary site)
• Brain
• Bone
• Liver
• Kidney
• Aerobic bacillus
• Passed from infected
• Humans
• Cows (bovine) and birds (avian)
• Much less common

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Antitubercular DrugsMycobacterium Infections

• Tubercle bacilli are conveyed by droplets
• Droplets are expelled by coughing or sneezing,
  then gain entry into the body by inhalation
• Tubercle bacilli then spread to other body organs
  via blood and lymphatic systems
• Tubercle bacilli may become dormant, or walled
  off by calcified or fibrous tissue

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Antitubercular DrugsTuberculosis -
Pathophysiology

• M. tuberculosis gram-positive, acid-fast
  bacillus
• Spread from person to person via airborne
  droplets
• Coughing, sneezing, speaking disperse organism
  and can be inhaled
• Not highly infectious requires close, frequent,
  and prolonged exposure
• Cannot be spread by hands, books, glasses,
  dishes, or other fomites

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Antitubercular DrugsTuberculosis Clinical
Manifestations

• Early stages free of symptoms
• Many cases are found incidentally
• Systemic manifestations
• Fatigue, malaise, anorexia, weight loss,
  low-grade fevers, night sweats
• Weight loss occurs late
• Characteristic cough frequent produces mucoid
  or mucopurulent sputum
• Dull or tight chest pain
• Some cases acute high fever, chills, general
  flulike symptoms, pleuritic pain, productive
  cough
• HIV Pt with TB Fever, cough, weight loss
• Pneumocystic carinii pneumonia (PCP)

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Antitubercular DrugsTuberculosis Diagnostic
Studies

• Tuberculin Skin Testing -- reaction 2-12 weeks
  after the initial infection
• PPD Purified protein derivative used to
  detect delayed hypersensitivity response
• Two-step testing health care workers
• 5mm gt induration Immunosuppressed patients
• 10 mmgt at risk populations health are workers
• 15 mmgt Low risk people
• Chest X-ray -- used in conjunction with skin
  testing
• Multinodular lymph node involvement with
  cavitation in the upper lobes of the lungs
• Calcification within several years after
  infection
• Bacteriologic Studies
• Sputum, gastric washings early morning specimens
  for acid-fast bacillus -- three consecutive
  cultures on different days
• CSF or pus from an abscess

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Antitubercular DrugsTuberculosis Medical
Management

• May be treated as outpatient
• Depends on debility and severity of symptoms
• Mainstay of treatment drug therapy for active
  disease
• Five primary drugs
• Isoniazid (INH) (primary drug used)
• Rifampin
• Pyrazinamide
• Streptomycin
• Ethambutol
• Combination 4 drug therapy
• HIV patients cannot take rifampin interferes
  with antiretroviral drug effectiveness

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Antitubercular Drugs

• Second-Line Drugs
• capreomycin amikacin
• cycloserine levofloxacin
• ethionamide ofloxacin
• kanamycin
• para-aminosalicyclic acid (PAS)

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Antitubercular Drug TherapyConsiderations

• Perform drug-susceptibility testing on the first
  Mycobacterium sp. that is isolated from a patient
  specimen to prevent the development of
  MDR-TB(Multidrug-resistant TB)
• Even before the results of susceptibility tests
  are known, begin a regimen with multiple
  antitubercular drugs
• Adjust drug regimen once the results of
  susceptibility testing are known
• Monitor patient compliance closely during therapy
• Problems with successful therapy
• patient nonadherence to drug therapy
• increased incidence of drug-resistant

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Antitubercular Therapy

• Effectiveness depends upon
• Type of infection
• Adequate dosing
• Sufficient duration of treatment
• Drug compliance
• Selection of an effective drug combination

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Antitubercular Therapy

• Problems
• Drug-resistant organisms
• Drug toxicity
• Patient noncompliance
• Multidrug-resistant TB (MDR-TB)

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Antitubercular Drugs Isoniazid (INH)

• Drug of choice for TB
• Resistant strains of Mycobacterium emerging
• Metabolized in the liver through
  acetylationwatch for slow acetylators
• Used alone or in combination with other drugs
• Used for the prophylaxis or treatment of TB

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Antitubercular Drugs Adverse Effects

• INH
• Peripheral neuritis, hepatotoxicity
• Ethambutol
• Retrobulbar neuritis, blindness
• Rifampin
• Hepatitis, discoloration of urine, stools

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Antitubercular DrugsNursing Implications

• Thorough medical history and physical assessment
• Perform liver function studies in patients who
  are to receive isoniazid or rifampin (especially
  in elderly patients or those who use alcohol
  daily)
• Assess for contraindications to the various
  drugs, conditions for cautious use, and potential
  drug interactions

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Antitubercular DrugsNursing Implications

• Monitor for therapeutic effects
• Decrease in symptoms of TB, such as cough and
  fever
• CS and CXR should confirm clinical findings
• Observe for lack of clinical response to therapy,
  indicating possible drug resistance
• Monitor for adverse effects
• Instruct patients on the adverse effects that
  should be reported to the physician immediately
• fatigue, nausea, vomiting, numbness and tingling
  of the extremities, fever, loss of appetite,
  depression, jaundice

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Antitubercular DrugsPatient Education

• 
  Patient education is critical
• Therapy may last for up to 24 months
• Take medications exactly as ordered, the same
  time every day
• Emphasize the importance of strict adherence to
  regimen for improvement of condition or cure
• Remind patients that they are contagious during
  the initial period of their illnessinstruct in
  proper hygiene and prevention of the spread of
  infected droplets
• Emphasize to patients to take care of themselves,
  including adequate nutrition and rest

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Antitubercular DrugsPatient Education

• Patients should not consume alcohol or take other
  medications, including OTC -- check with their
  physician
• INH and rifampin cause oral contraceptives to
  become ineffective another form of birth control
  will be needed
• Patients who are taking rifampin should be told
  that their urine, stool, saliva, sputum, sweat,
  or tears may become reddish orange even contact
  lenses may be stained
• Pyridoxine (Vitamin B6) may be needed to combat
  neurologic adverse effects associated with INH
  therapy
• Oral preparations may be given with meals to
  reduce GI upset, even though recommendations are
  to take them 1 hour before or 2 hours after meals