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Each tablet contains:
Composition
Isoniazid (INH).................................................................300
mg
Indications
Tuberculosis in children. Prophylaxis in children in contact with
open cases.
Description
Mechanism of action Isoniazid is a prodrug and must be activated
by bacterial catalase. The active form inhibits the synthesis of
mycolic acid in the mycobacterial cell wall. Isoniazid reaches
therapeutic concentrations in serum, cerebrospinal fluid (CSF),
and within caseous granulomas. Isoniazid is metabolized in the
liver via acetylation. There are two forms of the enzyme
responsible for acetylation, so that some patients metabolize the
drug quicker than others. Hence, the half-life is bimodal with
peaks at 1 hour and 3 hours in the US population. The metabolites
are excreted in the urine. Doses do not usually have to be
adjusted in case of renal failure. Isoniazid is bactericidal to
rapidly-dividing mycobacteria, but is bacteriostatic if the
mycobacterium is slow-growing. Side effects Adverse reactions
include rash, abnormal liver function tests, hepatitis,
sideroblastic anemia, peripheral neuropathy, mild central nervous
system (CNS) effects, and drug interactions resulting in increased
phenytoin (Dilantin) or disulfiram (Antabuse) levels. Peripheral
neuropathy and CNS effects are associated with the use of
isoniazid and are due to pyridoxine (vitamin B6) depletion, but
are uncommon at doses of 5 mg/kg. Persons with conditions in which
neuropathy is common (e.g., diabetes, uremia, alcoholism,
malnutrition, HIV-infection), as well as pregnant women and
persons with a seizure disorder, may be given pyridoxine (vitamin
B6) (10-50 mg/day) with isoniazid. Hepatoxicity can be avoided
with close Clinical monitoring of the patient, Specifically
Nausea, Vomiting, Abdominal pain and appetite. INH therapy will
also decrease the efficacy of hormonal birth control.
Side effects
Adverse reactions include rash, abnormal liver function tests,
hepatitis, sideroblastic anemia, peripheral neuropathy, mild
central nervous system (CNS) effects, and drug interactions
resulting in increased phenytoin (Dilantin) or disulfiram (Antabuse)
levels.
Peripheral neuropathy and CNS effects are associated with the use
of isoniazid and are due to pyridoxine (vitamin B6) depletion, but
are uncommon at doses of 5 mg/kg. Persons with conditions in which
neuropathy is common (e.g., diabetes, uremia, alcoholism,
malnutrition, HIV-infection), as well as pregnant women and
persons with a seizure disorder, may be given pyridoxine (vitamin
B6) (10-50 mg/day) with isoniazid.
Hepatoxicity can be avoided with close Clinical monitoring of the
patient, Specifically Nausea, Vomiting, Abdominal pain and
appetite.
INH therapy will also decrease the efficacy of hormonal birth
control.
Dosage
Adults: 3-5mg/kg body-wt. upto 300mg daily in a single dose.
Children: 10-20mg/kg body-wt. daily in single doses.
Presentations
10 tablets
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Quality
