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
Daraprim Pharmacology, Pharmacokinetics, Studies, Metabolism - Pyrimethamine
Daraprim Pharmacology, Pharmacokinetics, Studies, Metabolism - Pyrimethamine
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 plasmodia and Toxoplasma gondii.
Pyrimethamine possesses blood schizonticidal and some tissue
schizonticidal activity against malaria parasites of humans. However, the 4-amino-quinoline
compounds are more effective against the erythrocytic schizonts. It does not
destroy gametocytes, but arrests sporogony in the mosquito.
The action of pyrimethamine against Toxoplasma gondii is greatly
enhanced when used in conjunction with sulfonamides. This was demonstrated by
Eyles and Coleman1 in the treatment of experimental toxoplasmosis
in the mouse. Jacobs et al2 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.
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