A1,
A2,
B,
C1,
C2,
D,
E,
F,
G-H,
I-K,
L,
M,
N,
O,
P1,
P2,
Q-R,
S,
T,
U-V,
W-Z
Rifater Online, Description, Chemistry, Ingredients - Rifampin, Isoniazid and Pyrazinamide
Rifater Online, Description, Chemistry, Ingredients - Rifampin, Isoniazid and Pyrazinamide
DESCRIPTION
WARNING
Severe and sometimes fatal hepatitis associated with isoniazid therapy
may occur and may develop even after many months of treatment. The risk
of developing hepatitis is age related. Approximate case rates by age
are: 0 per 1,000 for persons under 20 years of age, 3 per 1,000 for persons
in the 20 to 34 year age group, 12 per 1,000 for persons in the 35 to
49 year age group, 23 per 1,000 for persons in the 50 to 64 year age group,
and 8 per 1,000 for persons over 65 years of age. The risk of hepatitis
is increased with daily consumption of alcohol. Precise data to provide
a fatality rate for isoniazid-related hepatitis is not available; however,
in a U.S. Public Health Service Surveillance Study of 13,838 persons taking
isoniazid, there were 8 deaths among 174 cases of hepatitis.
Therefore, patients given isoniazid should be carefully monitored and
interviewed at monthly intervals. Serum transaminase concentration becomes
elevated in about 10% to 20% of patients, usually during the first few
months of therapy, but it can occur at any time. Usually enzyme levels
return to normal despite continuance of drug, but in some cases progressive
liver dysfunction occurs. Patients should be instructed to report immediately
any of the prodromal symptoms of hepatitis, such as fatigue, weakness,
malaise, anorexia, nausea, or vomiting. If these symptoms appear or if
signs suggestive of hepatic damage are detected, isoniazid should be discontinued
promptly since continued use of the drug in these cases has been reported
to cause a more severe form of liver damage.
Patients with tuberculosis should be given appropriate treatment with
alternative drugs. If isoniazid must be reinstituted, it should be reinstituted
only after symptoms and laboratory abnormalities have cleared. The drug
should be restarted in very small and gradually increasing doses and should
be withdrawn immediately if there is any indication of recurrent liver
involvement. Treatment should be deferred in persons with acute hepatic
diseases.
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RIFATER (rifampin/isoniazid/pyrazinamide) tablets are combination tablets containing
120 mg rifampin, 50 mg isoniazid, and 300 mg pyrazinamide for use in antibacterial
therapy. The tablets also contain as inactive ingredients: povidone, carboxymethylcellulose
sodium, calcium stearate, sodium lauryl sulfate, sucrose, talc, acacia, titanium
dioxide, kaolin, magnesium carbonate, colloidal silicon dioxide, dried aluminum
hydroxide gel, ferric oxide, black iron oxide, carnauba wax, white beeswax,
colophony, hard paraffin, lecithin, shellac, and propylene glycol. The RIFATER
triple therapy combinaion was developed for dosing convenience.
Rifampin is a semisynthetic antibiotic derivative of rifamycin SV. Rifampin
is a red-brown crystalline powder very slightly soluble in water at neutral
pH, freely soluble in chloroform, soluble in ethyl acetate and methanol. Its
molecular weight is 822.95 and its chemical formula is C 43 H 58
N 4 O 12 . The chemical name for rifampin is either:
3-[[(4-methyl-1-piperazinyl) imino]-methyl]-rifamycin;
or
5, 6, 9, 17, 19, 21-hexahydroxy-23methoxy-2,4,12,16,18,-20,22 heptamethyl-8-
[N-(4-methyl-1-piperazinyl) formimidoyl]-2,7-(epoxypentadeca [1,11,13] trienimino)naphtho[2,1-b]furan-1,11
(2H)-dione 21-acetate.
Isoniazid is the hydroxide of isonicotinic acid. It is a colorless or white
crystalline powder or white crystals. It is odorless and slowly affected by
exposure to air and light. It is freely soluble in water, sparingly soluble
in alcohol and slightly soluble in chloroform and in ether. Its molecular weight
is 137.14 and its chemical formula is C 6 H 7 N 3
O. The chemical name for isoniazid is 4-pyridinecarboxylic acid, hydrazide.
Pyrazinamide, the pyrazine analogue of nicotinamide, is a white, crystalline
powder, stable at room temperature, and sparingly soluble in water. The chemical
name for pyrazinamide is pyrazinecarboxamide and its molecular weight is 123.11.
Its chemical formula is C 5 H 5 N 3 O.
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