Praziquantel warnings and precautions

# Warnings
Therapeutically effective levels of BILTRICIDE may not be achieved when administered concomitantly with strong P450 inducers, such as rifampin (see CONTRAINDICATIONS).

# Precautions

### General
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 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.

### Information for Patients
Patients should be warned not to drive a car and not to operate machinery on the day of BILTRICIDE treatment and the following day.

### Mutagenesis, Carcinogenesis
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.

### Nursing mothers
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 treatment and during the subsequent 72 hours.

### Pediatric use
Safety in children under 4 years of age has not been established.

### Geriatric use
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.