Names and pronunciation
(eye-soe-nye′a-zid) Isotamine
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Individual generic drug information
Extracted information for isoniazid only.
(eye-soe-nye′a-zid) Isotamine
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Func. class.: Antitubercular
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Chem. class.: Isonicotinic acid hydrazide
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ACTION: Bactericidal interference with lipid, nucleic acid biosynthesis
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USES: Treatment, prevention of TB
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Extracted information for isoniazid only.
CONTRAINDICATIONS: Hypersensitivity
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Black Box Warning: Acute hepatic dis- ease Precautions: Pregnancy, renal disease, diabetic retinopathy, cataracts, ocular defects, IV drug users, >35 yr, postpar- tum, HIV, neuropathy Black Box Warning: Alcoholism, females (African descent/Hispanic patients) Black Box Warning: Hepatic studies weekly: baseline in all patients, those >35 yr and all women should be moni- tored periodically; ALT, AST, bilirubin; in- creased test results may indicate hepa- titis; hepatic status: decreased appetite, jaundice, dark urine, fatigue; those with fast acetylation may metabolize product more than 5 times faster (black, Asian patients are at greater risk than some Caucasian patients); fatal hepatitis is a greater risk in black or Hispanic pa- tients after giving birth • DRESS: fever, flulike symptoms, rash, lymphadenopathy, facial swelling, may involve other organ systems • Stevens-Johnson syndrome, toxic epidermal necrolysis: rash, fever, fa tigue, blistering, discontinue immediately if these occur • Mental status often: affect, mood, be- havioral changes; psychosis may occur • Paresthesia in hands, feet • Susceptibility testing: obtain susceptibility tests before treatment and periodically; half of Mexicans, blacks, Caucasians, and Native Americans may be slow acetylators; Asians, Eskimos may be fast acetylators • Pregnancy/breastfeeding: use during pregnancy even 1st trimester for active TB, use only if benefits outweigh fetal risk for other indications; compatible with breastfeeding Black Box Warning: Fatal hepatitis: to notify prescriber immediately of yellow skin/eyes, dark urine, loss of appetite HIGH ALERT
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SIDE EFFECTS CNS: Peripheral neuropathy, dizziness, memory impairment, seizures, psychosis EENT: Blurred vision, optic neuritis GI: Nausea, vomiting, fatal hepatitis HEMA: Agranulocytosis, hemolytic, aplas tic anemia, thrombocytopenia, eosinophilia, methemoglobinemia Hypersensitivity: DRESS, Stevens-John son syndrome, toxic epidermal necrolysis, rash, fever
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INTERACTIONS Increase: toxicity—tyramine foods, alco- hol, cycloSERINE, ethionamide, rifAMPin, carBAMazepine, phenytoin, benzodiaze- pines, meperidine Increase: serotonin syndrome—SSRIs, SNRIs Decrease: absorption—aluminum ant- acids Decrease: effectiveness of BCG vac- cine—ketoconazole Drug/Food • Do not give with high-tyramine foods, alcohol Drug/Lab Test Increase: LFTs, bilirubin, glucose Decrease: platelets, granulocytes
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Extracted information for isoniazid only.
DOSAGE AND ROUTES • Adult/adolescent: PO/IM 5 mg/kg/day up to 300 mg/day or 15 mg/kg 2-3×/wk, max 900 mg 2-3×/wk • Child/infant with HIV: PO/IM 10-15 mg/kg/day, max 300 mg/day
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Available forms: Tabs 100, 300 mg; inj 100 mg/mL; oral sol 10 mg/mL
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Administer: PO route • PO with meals to decrease GI symp- toms; better to take on empty stomach 1 hr before or 2 hr after meals IM route • IM deep in large muscle mass; mas- sage; rotate injection site; warm inj to room temperature to dissolve crystals
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Extracted information for isoniazid only.
Assess:
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Evaluate: • Therapeutic response: decreased symptoms of TB
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CLINICAL CONSIDERATIONS
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Patient and caregiver information: • That compliance with dosage sched- ule, duration is necessary; not to skip or double dose • That scheduled appointments must be kept or relapse may occur • To avoid alcohol while taking product; may increase risk for hepatic injury • If diabetic, to use blood glucose moni- tor to obtain correct result • To report weakness, fatigue, loss of ap petite, nausea, vomiting, jaundice of skin or eyes, tingling/numbness of hands/feet
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Extracted information for isoniazid only.
PHARMACOKINETICS Metabolized in liver, 50% of patients may metabolize slowly, increasing toxic- ity; excreted in urine (metabolites), crosses placenta, excreted in breast milk; half life 1-4 hr (slow acetylators), 0.5- 1.5 hr (fast acetylators) PO: Peak 1-2 hr IM: Peak 45-60 min
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Filter the extracted dose blocks for this individual drug.
• Child/infant with HIV: PO/IM 10-15 mg/kg/day, max 300 mg/day
Candidate age grouping · source page 726