Isoniazid (inh)

Isoniazid (inh)

1. ISONIAZID (INH) PREPARED BY, MRS. RIJO LIJO

2. MECHANISM OF ACTION Mechanism : Isoniazid inhibits the synthesis of mycologic acids, an essential component of the bacterial cell wall. At therapeutic levels isoniazid is bactericidal against actively growing intracellular and extracellular Mycobacterium tuberculosis organisms. lsoniazid resistant Mycobacterium tuberculosis bacilli develop rapidly when lsoniazid monotherapy is administered.

3. INDICATION : Prophylaxis and treatment of tuberculosis.

4. CONTRAINDICATIONS : Isoniazid is contraindicated in patients who develop severe hypersensitivity reactions, including drug -induced hepatitis; previous isoniazid-associated hepatic injury; severe adverse reactions to isoniazid such as drug fever, chills, arthritis; and acute liver disease of any etiology.

5. DOSING : 10 mg/kg/day PO for the entire course of treatment. Max: 300 mg/day.

6. ADVERSE EFFECT : Common: Peripheral neuropathy . Uncommon: Memory impairment, optic neuritis and atrophy, toxic encephalopathy, convulsions, and toxic psychosis. Elevated serum transaminase (SGOT SGPT), jaundice, hyperbilirubinemia, nausea, vomiting, epigastric distress, thrombocytopenia, agranulocytosis, sideroblastic , hemolytic, or aplastic anemia, and eosinophilia, systemic Lupus Erythematosus, fever, lymphadenopathy, skin eruptions, vasculitis, pyridoxine deficiency, metabolic acidosis, hyperglycemia, pellagra, and gynecomastia.

7. NURSING RESPONSIBILTY Encourage the patient to eat small, frequent meals as tolerated; perform frequent mouth care; and drink adequate fluids to ensure adequate nutrition and hydration . Monitor nutrition if GI effects become a problem. Encourage that the patient is instructed about the appropriate dosage regimen, use of drug combinations and possible adverse effects to enhance patient knowledge about drug therapy and to promote compliance.

8. The Patient should inform: To drink a lot of fluids to maintain nutrition (very important) even though nausea, vomiting and diarrhea may occur. To use barrier contraceptives and understand that oral contraceptives may not be effective if antimycobacterial drugs are being used. To understand that normally some of these drugs impart an orange stain to body fluids. If this occurs, the fluids may say stain clothing and tears may stain contact lenses. To report difficulty breathing, hallucinations, numbness and tingling, worsening of condition, fever and chills or changes in color of urine or stool to a health care provider.

9. Evaluation: Monitor patient response to the drug (resolution of mycobacterial infection). Monitor for adverse effects (GI effects, CNS changes and hypersensitivity reactions). Evaluate the effectiveness of the teaching plan (patient can name the drug, dosage, possible adverse effects to expect and specific measure to help avoid adverse effects). Monitor the effectiveness of comfort and safety measures and compliance with the regimen.