BILTRICIDE (praziquantel) is a trematodicide provided in tablet form for the oral treatment of schistosome infections and infections due to liver fluke.

BILTRICIDE (praziquantel) is 2-(cyclohexylcarbonyl)-1,2,3,6,7, 11b-hexahydro-4H-pyrazino [2, 1-a] isoquinolin-4-one with the molecular formula; C₁₉H₂₄N₂O₂. The structural formula is as follows:

Praziquantel is a white to nearly white crystalline powder of bitter taste. The compound is stable under normal conditions and melts at 136-140°C with decomposition. The active substance is hygroscopic. Praziquantel is easily soluble in chloroform and dimethylsulfoxide, soluble in ethanol and very slightly soluble in water.

BILTRICIDE tablets contain 600 mg of praziquantel. Inactive ingredients: corn starch, magnesium stearate, microcrystalline cellulose, povidone, sodium lauryl sulfate, polyethylene glycol, titanium dioxide and hypromellose.

BILTRICIDE is indicated for the treatment of infections due to: all species of schistosoma (e.g. Schistosoma mekongi, Schistosoma japonicum, Schistosoma mansoni and Schistosoma hematobium), and infections due to the liver flukes, Clonorchis sinensis/Opisthorchis viverrini (approval of this indication was based on studies in which the two species were not differentiated).

The dosage recommended for the treatment of schistosomiasis is: 20 mg/kg bodyweight three times a day as a one day treatment, at intervals of not less than 4 hours and not more than 6 hours. The recommended dose for clonorchiasis and opisthorchiasis is: 25 mg/kg bodyweight three times a day as a one day treatment, at intervals of not less than 4 hours and not more than 6 hours. The tablets should be washed down unchewed with water during meals. Keeping the tablets or segments thereof in the mouth can reveal a bitter taste which can promote gagging or vomiting.

BILTRICIDE is supplied as a 600 mg white to orange tinged, film-coated, oblong tablet with three scores. The tablet is coded with "BAYER" on one side and "LG" on the reverse side. When broken, each of the four segments contains 150 mg of active ingredient so that the dosage can be easily adjusted to the patient's bodyweight.

Segments are broken off by pressing the score (notch) with thumbnails. If 1/4 of a tablet is required, this is best achieved by breaking the segment from the outer end. BILTRICIDE is available in bottles of 6 tablets.

Store below 86°F (30°C).

Manufactured by: Bayer HealthCare Pharmaceuticals Inc. Wayne, NJ 07470. Made in Germany. Distributed by: Schering Corporation, Kenilworth, NJ 07033. R.1 8/07. FDA Rev date: 7/14/2004

In general BILTRICIDE is very well tolerated. Side effects are usually mild and transient and do not require treatment. The following side effects were observed generally in order of severity: malaise, headache, dizziness, abdominal discomfort with or without nausea, rise in temperature and, rarely, urticaria. Such symptoms can, however, also result from the infection itself. Such side effects may be more frequent and/or serious in patients with a heavy worm burden.

Post Marketing Adverse Event Reports

Additional adverse events reported from worldwide post marketing experience and from publications with praziquantel include:

abdominal pain, allergic reaction (generalized hypersensitivity) including polyserositis, anorexia, arrhythmia (including bradycardia, ectopic rhythms, ventricular fibrillation, AV blocks), asthenia, bloody diarrhea, convulsion, myalgia, somnolence, vertigo, vomiting

Concomitant administration of drugs that increase the activity of drug metabolizing liver enzymes (Cytochrome P450), e.g. antiepileptic drugs (phenytoin, phenobarbital and carbamazepine), dexamethasone, may reduce plasma levels of praziquantel.

Concomitant administration of rifampin should be avoided (see WARNINGS).

Concomitant administration of drugs that decrease the activity of drug metabolizing liver enzymes (Cytochrome P 450), e.g. cimetidine, ketoconazole, itraconazole, erythromycin may increase plasma levels of praziquantel.

Chloroquine, when taken simultaneously, may lead to lower concentrations of praziquantel in blood. The mechanism of this drug-drug interaction is unclear.

Grapefruit juice was reported to produce a 1.6-fold increase in the Cmax and a 1.9-fold increase in the AUC of praziquantel. However, the effect of this exposure increase on the therapeutic effect and safety of praziquantel has not been systematically evaluated.

Therapeutically effective levels of praziquantel may not be achieved with concomitant administration of strong inducers of cytochrome P450 such as rifampin.

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.

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.

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. 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.

In rats and mice the acute LD₅₀ was about 2,500 mg/kg. No data are available in humans. In the event of overdose a fast-acting laxative should be given.

BILTRICIDE must not be given to patients who previously have shown hypersensitivity to the drug. Since parasite destruction within the eye may cause irreparable lesions, ocular cysticercosis should not be treated with this compound.

Praziquantel induces a rapid contraction of schistosomes by a specific effect on the permeability of the cell membrane. The drug further causes vacuolization and disintegration of the schistosome tegument.

After oral administration BILTRICIDE is rapidly absorbed (80%), subjected to a first pass effect, metabolized and eliminated by the kidneys. Maximal serum concentration is achieved 1-3 hours after dosing. The half-life of praziquantel in serum is 0.8-1.5 hours.

Special Populations: The pharmacokinetics of praziquantel were studied in 40 patients with Schistosoma mansoni infections with varying degrees of hepatic dysfunction (See table1). In patients with schistosomiasis, the pharmacokinetic parameters did not differ significantly between those with normal hepatic function (Group 1) and those with mild (Child-Pugh class A) hepatic impairment. However, in patients with moderate-to-severe hepatic dysfunction (Child-Pugh class B and C), praziquantel half-life, Cmax, and AUC increased progressively with the degree of hepatic impairment. In Child-Pugh class B, the increases in mean half-life, Cmax, and AUC relative to Group 1 were 1.58-fold, 1.76-fold, and 3.55-fold, respectively. The corresponding increases in Child-Pugh class C patients were 2.82-fold, 4.29-fold, and 15-fold for half-life, Cmax, and AUC.

Table 1: Pharmacokinetic parameters of praziquantel in four groups of patients with varying degrees of liver function following administration of 40 mg/kg under fasting conditions.

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

IMPORTANT NOTE: This is a summary and does not contain all possible information about this product. For complete information about this product or your specific health needs, ask your health care professional. Always seek the advice of your health care professional if you have any questions about this product or your medical condition. This information is not intended as individual medical advice and does not substitute for the knowledge and judgment of your health care professional. This information does not contain any assurances that this product is safe, effective, or appropriate for you.

PRAZIQUANTEL - ORAL

(prazz-ih-KWAN-tull)

COMMON BRAND NAME(S): Biltricide

USES: This medication is used to treat infections of certain parasites (e.g., Schistosoma and liver flukes). Curing parasitic infections helps to improve your health and quality of life. Praziquantel belongs to a class of drugs known as antihelmintics. It works by killing the parasites. It also paralyzes the parasites, causing them to release their hold on the blood vessel walls so the body can remove them naturally.

OTHER USES: This section contains uses of this drug that are not listed in the approved professional labeling for the drug but that may be prescribed by your health care professional. Use this drug for a condition that is listed in this section only if it has been so prescribed by your health care professional.

This drug may also be used to treat infections of other parasites (e.g., tapeworms, intestinal and lung flukes).

HOW TO USE: Take this medication by mouth with food, usually 3 times a day (4 to 6 hours apart) for 1 day or as directed by your doctor. Quickly swallow the tablets or tablet segments with a full glass of water (8 ounces or 240 milliliters). Do not chew or suck the tablets because the bitter taste of praziquantel may cause gagging or vomiting. Your doctor may direct you to take this medication fewer than 3 times a day or to take it for longer than 1 day. Follow your doctor's directions exactly.

Dosage is based on your medical condition, weight, and response to treatment. Tablets are scored with lines. You may need to break the tablet to get the correct dose. Ask your pharmacist for directions on breaking the tablet to get the right dose for you.

Avoid eating grapefruit or drinking grapefruit juice while using this medication unless your doctor instructs you otherwise.

Tell your doctor if your condition persists or worsens.

SIDE EFFECTS: Headache, dizziness, stomach pain, nausea, tiredness, weakness, joint/muscle pain, loss of appetite, vomiting, and sweating may occur. These side effects are usually mild and temporary and may be symptoms of your parasite infection and/or the dying parasites. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor immediately if any of these rare but very serious side effects occur: bloody diarrhea, fever, irregular/slow heartbeat, seizures.

A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including: rash, itching, swelling, severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

Contact your doctor for medical advice about side effects. The following numbers do not provide medical advice, but in the US you may report side effects to the Food and Drug Administration (FDA) at 1-800-FDA-1088. In Canada, you may call Health Canada at 1-866-234-2345.

PRECAUTIONS: Before taking praziquantel, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies.

This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have: parasitic eye infection (ocular cysticercosis).

Before using this medication, tell your doctor or pharmacist your medical history, especially of: liver disease/enlarged spleen, heart disease/irregular heart rhythm, parasitic brain infection (cerebral cysticercosis), seizures.

This drug may make you dizzy or drowsy during treatment until the day after treatment. Use caution while driving, using machinery, or doing any activity that requires alertness. Limit alcoholic beverages.

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

This drug passes into breast milk. Breast-feeding while using this drug is not recommended. Nursing mothers should temporarily stop breast-feeding on the day of treatment and for 72 hours after taking the last dose. Pump and discard breast milk during this time.

DRUG INTERACTIONS: Your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor or pharmacist first.

This drug should not be used with the following medication because a very serious interaction may occur: rifampin.

If you are currently using the medication listed above, tell your doctor or pharmacist before starting praziquantel.

Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription/herbal products you may use, especially of: chloroquine, drugs affecting liver enzymes that remove praziquantel from your body (e.g., cimetidine, dexamethasone, azole antifungals such as ketoconazole/itraconazole, macrolide antibiotics such as erythromycin, anti-seizure medicines such as carbamazepine/phenytoin/phenobarbital).

This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist.

OVERDOSE: If overdose is suspected, contact your local poison control center or emergency room immediately. US residents can call the US National Poison Hotline at 1-800-222-1222. Canada residents can call a provincial poison control center.

NOTES: Do not share this medication with others.

Laboratory and/or medical tests (e.g., examination of urine/stool, biopsy of infected tissue) should be performed periodically to monitor your progress or check for side effects. If you have a heart condition, you may need additional monitoring. Consult your doctor for more details.

MISSED DOSE: If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.

STORAGE: Store below 86 degrees F (30 degrees C) away from light and moisture. Do not store in the bathroom. Keep all medicines away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details about how to safely discard your product.

Information last revised July 2008 Copyright(c) 2008 First DataBank, Inc.