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
Gris Peg Warnings, Precautions, Pregnancy, Nursing, Abuse - Griseofulvin
Gris Peg Warnings, Precautions, Pregnancy, Nursing, Abuse - Griseofulvin
WARNINGS
Prophylactic Usage
Safty and efficacy
of griseofulvin
for prophylaxis
of fungal infections have not been established.
Since griseofulvin
has demonstrated harmful effects in vitro on the genotype
in bacteria, plants,
and fungi, males should wait at least 6 months after completing
griseofulvin therapy
before fathering a child. Females should avoid risk
of pregnancy while
receiving griseofulvin
therapy.
Animal Toxicology
Chronic feeding of
griseofulvin, at levels ranging from 0.5-2.5% of the diet,
resulted in the development
of liver tumors in several
strains of mice, particularly in males. Smaller particle
sizes result in an enhanced effect. Lower oral
dosage levels have not
been tested. Subcutaneous administration of relatively small doses
of griseofulvin
once a week during the first 3 weeks of life
has also been reported to induce hepatomata in mice. Thyroid tumors,
mostly adenomas but some carcinomas, have been reported in male
rats receiving griseofulvin
at levels of 2.0%, 1.0%, and 0.2% of the diet, and in female
rats receiving the two higher dose
levels. Although studies in other animal
species have not yielded
evidence of tumorigenicity,
these studies were not of adequate design to form
a basis for conclusions
in this regard.
In subacute toxicity
studies, orally administered griseofulvin
produced hepato-cellular necrosis
in mice, but this has not been seen in other species. Disturbances
in porphyrin metabolism
have been reported in griseofulvin-treated laboratory animals. Griseofulvin
has been reported to have a colchicine-like effect on mitosis
and cocarcinogenicity with methylcholanthrene in cutaneous tumor
induction in laboratory
animals.
Griseofulvin interferes with chromosomal distribution
during cell division, causing
aneuploidy in plant
and mammalian cells. These effects have been demonstrated in
vitro at concentrations that may be achieved in the serum
with the recommended therapeutic
dosage.
Usage in Pregnancy
Griseofulvin should not be prescribed to pregnant
patients or to women contemplating pregnancy
(see CONTRAINDICATIONS).
Animal Reproduction Studies
It has been reported in the literature that griseofulvin
was found to be embryotoxic and teratogenic
on oral administration
to pregnant rats. Pups
with abnormalities have been reported in the litters of a few bitches
treated with griseofulvin. .
Suppression of spermatogenesis
has been reported to occur in rats, but investigation in man
failed to confirm this.
PRECAUTIONS
Patients on prolonged therapy
with any potent medication
should be under close observation. Periodic monitoring of organ
system function, including
renal, hepatic, and
hematopoietic, should be done. Since griseofulvin
is derived from species
of Penicillium, the possibility of cross-sensitivity with penicillin
exists; however, known, penicillin-sensitive patients have been
treated without difficulty. Since a photosensitivity
reaction is occasionally
associated with griseofulvin
therapy, patients should
be warned to avoid exposure too intense natural
or artificial sunlight.
Lupus erythematosus or lupus-like syndromes, or exacerbation
of existing lupus, have been reported in patients receiving griseofulvin.
Drug Interactions
Griseofulvin decreases the activity
of warfarin-type anticoagulants so that patients receiving these
drugs concomitantly may require dosage adjustment of the anticoagulant
during and after griseofulvin
therapy.
Barbiturates usually depress griseofulvin
activity, and concomitant administration may require a dosage
adjustment of the
antifungal agent.
The effects of alcohol
may be potentiated by griseofulvin, producing such effects as tachycardia
and flush.
Griseofulvin may potentiate
an increase in hepatic
enzymes that metabolize estrogens at an increased rate, including
the estrogen component
of oral contraceptives, thereby causing possible decreased contraceptive
effects and menstrual irregularities.
top
