Therapeutically effective levels of BILTRICIDE (praziquantel) may not be achieved when administered
concomitantly with strong P450 inducers, such as rifampin (see CONTRAINDICATIONS).
Approximately 80% of a dose of praziquantel is excreted in the kidneys, almost
exclusively ( > 99%) in the form of metabolites. Excretion might be delayed
in patients with impaired renal function, but accumulation of unchanged drug
would not be expected. Therefore, dose adjustment for renal impairment is not
considered necessary. Nephrotoxic effects of praziquantel or its metabolites
are not known.
Caution should be exercised in the administration of the usual recommended
dose of praziquantel to hepatosplenic schistosomiasis patients with moderate
to severe liver impairment (Child-Pugh class B and C). Reduced metabolism of
praziquantel by the liver in these patients may lead to considerably higher
and longer lasting plasma concentrations of unmetabolized praziquantel (See
CLINICAL PHARMACOLOGY/Special Populations).
Minimal increases in liver enzymes have been reported in some patients.
Patients suffering from cardiac irregularities should be monitored during treatment.
As BILTRICIDE (praziquantel) can exacerbate central nervous system pathology due to schistosomiasis,
as a general rule this drug should not be administered to individuals reporting
a history of epilepsy and/or other signs of potential central nervous systems
involvement such as subcutaneous nodules suggestive of cysticercosis.
When schistosomiasis or fluke infection is found to be associated with cerebral
cysticercosis it is advised to hospitalize the patient for the duration of treatment.
Mutagenic effects in Salmonella tests found by one laboratory have not been
confirmed in the same tested strain by other laboratories. Long term carcinogenicity
studies in rats and golden hamsters did not reveal any carcinogenic effect.
Pregnancy Category B
Reproduction studies have been performed in rats and rabbits at doses up to
40 times the human dose and have revealed no evidence of impaired fertility
or harm to the fetus due to praziquantel. There are, however, no adequate and
well-controlled studies in pregnant women. An increase of the abortion rate
was found in rats at three times the single human therapeutic dose. While animal
reproduction studies are not always predictive of human response, this drug
should be used during pregnancy only if clearly needed.
Praziquantel appeared in the milk of nursing women at a concentration of about
1/4 that of maternal serum although it is not known whether a pharmacological
effect is likely to occur in children. Women should not nurse on the day of
BILTRICIDE (praziquantel) treatment and during the subsequent 72 hours.
Safety in children under 4 years of age has not been established.
Clinical studies of praziquantel did not include a sufficient number of subjects
ages 65 and over to determine whether they respond differently from younger
subjects. Other reported clinical experience has not identified differences
in responses between the elderly and younger patients, but greater sensitivity
of some older patients cannot be ruled out.
This drug is known to be substantially excreted by the kidney. Because elderly
patients are more likely to have decreased renal function, the risk of toxic
reactions to this drug may be greater in these patients.