DOSAGE AND ADMINISTRATION
(See also INDICATIONS AND USAGE)
For preventive therapy of tuberculous infection and
treatment of tuberculosis, it is recommended that physicians be familiar with
the following publications: (1) the recommendations of the Advisory Council for
the Elimination of Tuberculosis, published in the MMWR: vol 42; RR-4, 1993 and
(2) Treatment of Tuberculosis and Tuberculosis Infection in Adults and
Children, American Journal of Respiratory and Critical Care Medicine: vol 149;
For Treatment Of Tuberculosis
Isoniazid is used in conjunction with other effective
anti-tuberculous agents. Drug susceptibility testing should be performed on the
organisms initially isolated from all patients with newly diagnosed tuberculosis.
If the bacilli becomes resistant, therapy must be changed to agents to which
the bacilli are susceptible.
Usual Oral Dosage (depending on the regimen used):
5 mg/kg up to 300 mg daily in a single dose; or
15 mg/kg up to 900 mg/day, two or three times/week
10 mg/kg to 15 mg/kg up to 300 mg daily in a single dose;
20 mg/kg to 40 mg/kg up to 900 mg/day, two or three
Patients with Pulmonary Tuberculosis Without HIV
There are 3 regimen options for the initial treatment of
tuberculosis in children and adults:
Daily isoniazid, rifampin and pyrazinamide for 8 weeks
followed by 16 weeks of isoniazid and rifampin daily or 2 to 3 times weekly.
Ethambutol or streptomycin should be added to the initial regimen until sensitivity
to isoniazid and rifampin is demonstrated. The addition of a fourth drug is
optional if the relative prevalence of isoniazid-resistant Mycobacterium
tuberculosis isolates in the community is less than or equal to four percent.
Daily isoniazid, rifampin, pyrazinamide and streptomycin
or ethambutol for 2 weeks followed by twice weekly administration of the same
drugs for 6 weeks, subsequently twice weekly isoniazid and rifampin for 16
Three times weekly with isoniazid, rifampin, pyrazinamide
and ethambutol or streptomycin for 6 months.
*All regimens given twice weekly or 3 times weekly should
be administered by directly observed therapy [see also Directly Observed
The above treatment guidelines apply only when the
disease is caused by organisms that are susceptible to the standard
antituberculous agents. Because of the impact of resistance to isoniazid and
rifampin on the response to therapy, it is essential that physicians initiating
therapy for tuberculosis be familiar with the prevalence of drug resistance in
their communities. It is suggested that ethambutol not be used in children
whose visual acuity cannot be monitored.
Patients with Pulmonary Tuberculosis and HIV Infection
The response of the immunologically impaired host to
treatment may not be as satisfactory as that of a person with normal host
responsiveness. For this reason, therapeutic decisions for the impaired host must
be individualized. Since patients co-infected with HIV may have problems with
malabsorption, screening of antimycobacterial drug levels, especially in
patients with advanced HIV disease, may be necessary to prevent the emergence
Patients with Extra Pulmonary Tuberculosis
The basic principles that underlie the treatment of
pulmonary tuberculosis also apply to Extra pulmonary forms of the disease.
Although there have not been the same kinds of carefully conducted controlled trials
of treatment of Extra pulmonary tuberculosis as for pulmonary disease,
increasing clinical experience indicates that a 6 to 9 month short-course
regimen is effective. Because of the insufficient data, miliary tuberculosis,
bone/joint tuberculosis and tuberculous meningitis in infants and children should
receive 12 month therapy.
Bacteriologic evaluation of Extra pulmonary tuberculosis
may be limited by the relative inaccessibility of the sites of disease. Thus,
response to treatment often must be judged on the basis of clinical and radiographic
The use of adjunctive therapies such as surgery and
corticosteroids is more commonly required in Extra pulmonary tuberculosis than
in pulmonary disease. Surgery may be necessary to obtain specimens for
diagnosis and to treat such processes as constrictive pericarditis and spinal
cord compression from Pott's Disease. Corticosteriods have been shown to be of
benefit in preventing cardiac constriction from tuberculous pericarditis and in
decreasing the neurologic sequelae of all stages of tuberculosis Â meningitis,
especially when administered early in the course of the disease.
Pregnant Women with Tuberculosis
The options listed above must be adjusted for the
pregnant patient. Streptomycin interferes with in utero development of the ear
and may cause congenital deafness. Routine use of pyrazinamide is also not recommended
in pregnancy because of inadequate teratogenicity data. The initial treatment
regimen should consist of isoniazid and rifampin. Ethambutol should be included
unless primary isoniazid resistance is unlikely (isoniazid resistance rate
documented to be less than 4%).
Treatment of Patients with Multi-Drug Resistant
Multiple-drug resistant tuberculosis (i.e., resistance to
at least isoniazid and rifampin) presents difficult treatment problems.
Treatment must be individualized and based on susceptibility studies. In such
cases, consultation with an expert in tuberculosis is recommended.
Directly Observed Therapy (DOT)
A major cause of drug-resistant tuberculosis is patient
noncompliance with treatment. The use of DOT can help assure patient compliance
with drug therapy. DOT is the observation of the patient by a health care
provider or other responsible person as the patient ingests anti-tuberculosis
medications. DOT can be achieved with daily, twice weekly or thrice weekly
regimens and is recommended for all patients.
For Preventative Therapy Of Tuberculosis
Before isoniazid preventive therapy is initiated,
bacteriologically positive or radiographically progressive tuberculosis must be
excluded. Appropriate evaluations should be performed if Extra pulmonary
tuberculosis is suspected.
Adults over 30 kg: 300 mg per day in a single dose.
Infants and Children: 10 mg/kg (up to 300 mg daily) in a
single dose. In situations where adherence with daily preventative therapy cannot
be assured, 20 mg/kg to 30 mg/kg (not to exceed 900 mg) twice weekly under the
direct observation of a health care worker at the time of administration8.
Continuous administration of isoniazid for a sufficient
period is an essential part of the regimen because relapse rates are higher if
chemotherapy is stopped prematurely. In the treatment of tuberculosis, resistant
organisms may multiply and the emergence of resistant organisms during the
treatment may necessitate a change in the regimen.
For following patient compliance: the Potts-Cozart test9,
a simple colorimetric6 method of checking for isoniazid in the
urine, is a useful tool for assuring patient compliance, which is essential for
effective tuberculosis control. Additionally, isoniazid test strips are also
available to check patient compliance.
Concomitant administration of pyridoxine (B6)
is recommended in the malnourished and in those predisposed to neuropathy
(e.g., alcoholics and diabetics).
Isoniazid Tablets, USP, for oral administration, are
available as following strengths :
White, round, biconvex, scored on one side and debossed
with E over and “4354” below the score and supplied as:
Bottles of 30 tablets NDC 0185-4351-30
Bottles of 100 tablets NDC 0185-4351-01
Bottles of 1000 tablets NDC 0185-4351-10
White, round, biconvex, scored on one side and debossed
with E over and “4350” below the score and supplied as:
Bottles of 30 tablets NDC 0185-4350-30
Bottles of 100 tablets NDC 0185-4350-01
Bottles of 1000 tablets NDC 0185-4350-10
Store at 20° to 25°C (68° to 77°F) [see USP Controlled
Room Temperature]. Protect from moisture and light.
To report SUSPECTED ADVERSE REACTIONS, contact Sandoz
Inc. at 1-800-525-8747 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
6. American Thoracic Society/Centers for Disease Control:
Treatment of Tuberculosis and Tuberculosis Infection in Adults and Children.
Amer. J. Respir Crit Care Med.1994;149: p1359- 1374.
8. Committee on infectious Diseases American Academy of
Pediatrics:1994, Red Book: Report of the Committee on Infectious Diseases; 23
9. Schraufnagel, DE; Testing for Isoniazid; Chest (United
States) 1990: August; 98 (2) p314-316.
Manufactured for: Sandoz Inc., Princeton, NJ 08540. Manufactured
by: Epic Pharma, LLC, Laurelton, NY 11413. Revised: Apr 2016