PYRIMETHAMINE tablet

Country: United States

Language: English

Source: NLM (National Library of Medicine)

Active ingredient:

PYRIMETHAMINE (UNII: Z3614QOX8W) (PYRIMETHAMINE - UNII:Z3614QOX8W)

Available from:

DR.REDDYS LABORATORIES INC

Administration route:

ORAL

Prescription type:

PRESCRIPTION DRUG

Therapeutic indications:

Treatment of Toxoplasmosis: Pyrimethamine is indicated for the treatment of toxoplasmosis when used conjointly with a sulfonamide, since synergism exists with this combination. Use of Pyrimethamine is contraindicated in patients with known hypersensitivity to pyrimethamine or to any component of the formulation. Use of the drug is also contraindicated in patients with documented megaloblastic anemia due to folate deficiency.

Product summary:

Pyrimethamine Tablets USP, 25 mg are supplied as: White, round, biconvex, scored tablet, with C/127 on the upper side; and plain on the lower side in bottles of 100 (NDC 43598-672-01) and bottles of 30 (NDC 43598-672-30) Store at 15° to 25°C (59° to 77°F) in a dry place and protect from light.

Authorization status:

Abbreviated New Drug Application

Summary of Product characteristics

PYRIMETHAMINE- PYRIMETHAMINE TABLET
DR.REDDYS LABORATORIES INC
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PRESCRIBING INFORMATION
DESCRIPTION
Pyrimethamine is an antiparasitic compound available in tablet form
for oral
administration. Each scored tablet contains 25 mg pyrimethamine and
the inactive
ingredients pregelatinized starch, lactose monohydrate, and magnesium
stearate.
Pyrimethamine, known chemically as
5-(4-chlorophenyl)-6-ethyl-2,4-pyrimidinediamine,
has the following structural formula:
C
H
CIN
Mol. Wt. 248.71
“FDA approved dissolution test specifications differ from USP”.
CLINICAL PHARMACOLOGY
Pyrimethamine is well absorbed with peak levels occurring between 2 to
6 hours
following administration. It is eliminated slowly and has a plasma
half-life of
approximately 96 hours. Pyrimethamine is 87% bound to human plasma
proteins.
MICROBIOLOGY: Pyrimethamine is a folic acid antagonist and the
rationale for its
therapeutic action is based on the differential requirement between
host and parasite for
nucleic acid precursors involved in growth. This activity is highly
selective against
_Toxoplasma gondii_.
The action of pyrimethamine against _Toxoplasma gondii_ is greatly
enhanced when used
in conjunction with sulfonamides. This was demonstrated by Eyles and
Coleman in the
treatment of experimental toxoplasmosis in the mouse. Jacobs et al
demonstrated that
combination of the 2 drugs effectively prevented the development of
severe uveitis in
most rabbits following the inoculation of the anterior chamber of the
eye with
toxoplasma.
INDICATIONS AND USAGE
TREATMENT OF TOXOPLASMOSIS: Pyrimethamine is indicated for the
treatment of
12
13
4
1
2
toxoplasmosis when used conjointly with a sulfonamide, since synergism
exists with this
combination.
CONTRAINDICATIONS
Use of Pyrimethamine is contraindicated in patients with known
hypersensitivity to
pyrimethamine or to any component of the formulation. Use of the drug
is also
contraindicated in patients with documented megaloblastic anemia due
to folate
deficiency.
WARNINGS
The dosage of pyrimethamine