Tuberculosis And Antitubercular Drugs Flashcards
(33 cards)
What is tuberculosis?
Which is the most common form?
Tuberculosis: medical diagnosis of any infection caused by a bacterial species called mycobacterium. Caused either by mycobacterium tuberculosis (MTB —> most common) and M. bovis
Most common: mycobacterium tuberculosis: need large supply of oxygen to grow and flourish (aerobic) —> most commonly found in lungs
What are some signs and symptoms of TB?
- SOB
- coughing up blood
- cough lasting more than 2 weeks
- weight loss
- chest pain
- weakness and datigue
- loss of appetite
- fever
- night sweating
- chills
- sputum
What are some TB testing tests?
- PTB test (to detect TB —> if positive then X ray)
- X-ray (to identify presence of nofules if yes sputum test done)
- Sputum culture test (med regime might be changed depending on results)
What is the antituberculin treatment intensive vs continuation?
Intensive:
- combination of meds rapidly destroy TB bacilli and improve conditions
- reduces disease transmission
- tx of 2months take 5x per week
- main meds given together to prevent drug resistance : isoniazid, rifampin, pyrazinamide and ethambutol
Continuation:
- lenght of tx varies
- based on risk of relapse
- given daily or intermittently 3days a week
- consists of use of 2 drugs
What is the Classification of the TB meds?
Name the prototypes meds for tx of TB.
Classification: aminoglycoside antibiotics
Prototype meds:
- INH (isoniazid-isotamine)
- Rifampin
- Ethambutol
- streptomycin
What is the mechanism of action and the indications for aminoglycoside antibiotic therapy for TB?
Mechanism of action:
- inhibit cell wall synthesis
- act on MTB inhibiting protein synthesis
- reduce symptoms and infectiousness of pt
Indication: TB infectiond (pulmonary and extra pulmonary)
What are some contraindications and interactions with aminoglycosides antibiotics for TB? ( isoniazid and streptomycin)
Contraindications:
- severe drug allergies
- major kidney/liver dysfunction
- chronic alcohol use
Interactions:
- Isoniazid: cause false positive urine test glucose reading
- Elevate levels of liver enzyme
What are some drug interactions with INH (isoniazid- isotamine)?
- Antacid: reduce absorption
- rifampin: additive effect = increase risk of CNS and hepatotoxicity
- phenytoin and carbamazepine: decrease metabolism so increase effect of these meds
What are some AE with INH (isoniazid-isotamine)? (TB meds)
And what is the contraindication?
- peripheral neuropathy
- hepatotoxicity
- pyridoxine (vitamin b6) deficiency
- optic neuritis
- visual disturbances
- hyperglycemia
Contraindication:
Acute liver disease
What is the indication for INH (isoniazid-isotamine)?
And how does it work?
Indication: used in pregnant women with TB
Works by disrupting cell wall synthesis (bactericidal)
What is the specific AE of rifampin?
And name other AE as well.
Specific: discoloration of urina, tears, sweat, sputum, etc.. (may be red, orange, brown, )
- hematological disorders
- hepatitis
What are some drug interactions with Rifampin?
Increased metabolism so decreased therapeutic effect with:
- beta blockers
- benzodiazepines
- cyclosporine
- oral anticoagulant
- oral antihyperglycemics
- oral contraceptives
- phenytoin
- quinidine sulphate
- sirolimus
- theophylline
What are some indications for Rifampin?
Forms available.
- used in combination with other antitubercular aminoglycoside antibiotics for TB txs
- used in preventative therapy
- safe during pregnancy
Available PO
What are the different mechanism of action for each antitubercular drug (aminoglycoside antibiotics)?
- Rifampin: inhibits RNA and DNA synthesis —> inhibits protein synthesis
- streptomycin: interferes with normal protein synthesis—> inhibits protein synthesis
- isoniazid: inhibits synthesis of the cell wall
- ethambutol: affects lipid synthesis ehich inhibits protein synthesis
Which antitubercular drugs (3) are safe during pregnancy?
- isoniazid (INH)
- rifampin
- ethambutol
Why are Vitamin B6 given in supplements when a pt is on Isoniazid therapy?
Because isoniazid is noted to cause pyridoxine deficiency and liver toxicity so vitamin B6 (25mg daily) helps prevent those complications.
Indications for each antitubercular drugs:
- Ethambutol: first linr drug for tx of TB
- isoniazid (INH): used alone or in combi with other anti tb drugs for tx of pulmonary and extra pulmonary mtb after failure of first line tx
- rifampin: used with other anti tb meds in the tx of tb
- streptomycin: used in combo with other anti tb drugs for tx of tb
What are the contraindications for Ethambutol (Etibi)?
And what is its AE?
Contraindication:
Children younger than 12yrs old
Pt with optic neuritis
AE: Optic neuritis (lead to vision problem)
Which antitubercular drug is available only in IM injection form?
A) ethambutol
B) isoniazid (INH)
C) rifampin
D) streptomycin
D)
All the others are available PO
What are some AE of streptomycin?
- ototoxicity
- nephrotoxicity
- neurotoxicity
- blood dyscrasias
Which prototype med is part of the second line drug in tx of TB?
A) isoniazid (INH) B) streptomycin C) rifampin D) ethambutol E) pyrazinamide
B)
What are some drug interactions with isoniazid (INH) (TB med)?
Antacids : Reduce absorption= reduce isoniazid levels
Rifampin: has additive effects which leads to increased CNS and hepatotoxicity
What sre some drug interactions with streptomycin?
- Nephrotoxic drugs and neurotoxic drugs: have additive effects and increase toxicity
- oral anticoagulants: alter intestinal flora increAsing bleeing tendencies
What are some nursing assessments to be done before administering antitubercular drugs?
General vs drug specific
General:
- PPD test
- tuberculin skin test
- review most recent X ray
- liver function tests (bilirubin and liver enzyme levels)
- kidney function studies (GFR, BUN, creatinine clearance)
- baseline neuro functioning (due to risk of peripheral neuropathy)
- assess age
Specific :
- hearing status especially with streptomycin
- eye exam due to optic neuritis and visual disturbances with isoniazid and ethambutol
- complete blood count due to risk of hematological disorders with isoniazid, streptomycin and rifampin
- kidney studies due to risk of nephrotoxixity with streptomycin
