MINTEZOL (Thiabendazole) is an anthelmintic provided as 500 mg chewable tablets, and as a suspension, containing 500 mg thiabendazole per 5 mL. The suspension also contains sorbic acid 0.1% added as a preservative. Inactive ingredients in the tablets are acacia, calcium phosphate, flavors, lactose, magnesium stearate, mannitol, methylcellulose, and sodium saccharin. Inactive ingredients in the suspension are an antifoam agent, flavors, polysorbate, purified water, sorbitol solution, and tragacanth.

Thiabendazole is a white to off-white odorless powder with a molecular weight of 201.26, which is practically insoluble in water but readily soluble in dilute acid and alkali. Its chemical name is 2-(4-thiazolyr)-1/-/-benzimidazole. The empirical formula is C₁₀H₇N₃S and the structural formula is:

MINTEZOL is indicated for the treatment of: Strongyloidiasis (threadworm) Cutaneous larva migrans (creeping eruption) Visceral larva migrans

Trichinosis: Relief of symptoms and fever and a reduction of eosinophilia have followed the use of MINTEZOL during the invasion stage of the disease.

Thiabendazole is usually inappropriate as first line therapy for enterobiasis (pinworm). However, when enterobiasis occurs with any of the conditions listed above, additional therapy is not required for most patients.

MINTEZOL should be used only in the following infestations when more specific therapy is not available or cannot be used or when further therapy with a second agent is desirable: Uncinariasis (hookworm: Necator americanus and Ancylostoma duodenale); Trichuriasis (whipworm); Ascariasis (large roundworm).

The recommended maximum daily dose of MINTEZOL is 3 grams.

MINTEZOL should be given after meals if possible. Tablets MINTEZOL should be chewed before swallowing. Dietary restriction, complementary medications and cleansing enemas are not needed.

The usual dosage schedule for all conditions is two doses per day. The dosage is determined by the patient's weight.

A weight-dose chart follows:

The regimen for each indication follows:

Therapeutic Regimens

No. 3331 — MINTEZOL Suspension, 500 mg per 5 mL, is white to off-white and is supplied as follows:

NDC 0006-3331-60 in bottles of 120 mL
(6505-00-935-5835, 0.5 g/5 mL, 120 mL).

Storage

Store in a well-closed container at controlled room temperature [15-30°C (59-86°F)]. Protect from freezing.

No. 3332 — MINTEZOL Chewable Tablets, 500 mg, are white to off-white, orange-flavored, round, scored, compressed tablets, coded MSD 907 on one side and MINTEZOL on the other.

They are supplied as follows:

NDC 0006-0907-36 unit dose packages of 36
(6505-01-226-9909, 500 mg chewable, individually sealed 36's).

Storage

Store in a well-closed container at controlled room temperature [15-30°C (59-86°F)].

MERCK & CO., INC., Whitehouse Station, NJ 08889, USA. Issued June 2003. FDA rev date: 6/11/2003

Gastrointestinal: anorexia, nausea, vomiting, diarrhea, epigastric distress, abdominal pain, jaundice, cholestasis, parenchymal liver damage and hepatic failure. (See WARNINGS.)

Central Nervous System: dizziness, weariness, drowsiness, giddiness, headache, numbness, hyperirritability, convulsions, collapse, confusion, depression, floating sensation, weakness and lack of coordination.

Special Senses: tinnitus, abnormal sensation in eyes, xanthopsia, blurred vision, reduced vision, drying of mucous membranes (mouth, eyes, etc.), Sicca syndrome. (See WARNINGS.)

Cardiovascular: hypotension.

Metabolic: hyperglycemia.

Hematologic: transient leukopenia.

Genitourinary: hematuria, enuresis, malodor of the urine, crystalluria.

Hypersensitivity: pruritus, fever, facial flush, chills, conjunctival injection, angioedema, anaphylaxis, skin rashes (including perianal), erythema multiforme (including Stevens-Johnson syndrome), and lymphadenopathy.

Miscellaneous: appearance of live Ascaris in the mouth and nose.

Thiabendazole may compete with other drugs, such as theophylline, for sites of metabolism in the liver, thus elevating the serum levels of such compounds to potentially toxic levels. Therefore, when concomitant use of thiabendazole and xanthine derivatives is anticipated, it may be necessary to monitor blood levels and/or reduce the dosage of such compounds. Such concomitant use should be administered under careful medical supervision.

If hypersensitivity reactions occur, the drug should be discontinued immediately and not be resumed. Erythema multiforme has been associated with thiabendazole therapy; in severe cases (Stevens-Johnson syndrome), fatalities have occurred.

Because CNS side effects may occur quite frequently, activities requiring mental alertness should be avoided.

Jaundice, cholestasis, and parenchymal liver damage have been reported in patients treated with MINTEZOL. In rare cases, liver damage has been severe and has led to irreversible hepatic failure. (See ADVERSE REACTIONS.)

Abnormal sensation in eyes, xanthopsia, blurred vision, drying of mucous membranes, and Sicca syndrome have been reported in patients treated with MINTEZOL. These adverse effects of the eye were in some cases persistent for prolonged intervals which have exceeded one year. (See ADVERSE REACTIONS.)

Thiabendazole should not usually be used as first line therapy for the treatment of enterobiasis. It should be reserved for use in patients who have experienced allergic reactions, or resistance to other treatments.

General

MINTEZOL is not suitable for the treatment of mixed infections with ascaris because it may cause these worms to migrate.

Ideally, supportive therapy is indicated for anemic, dehydrated or malnourished patients prior to initiation of the anthelmintic therapy.

In the presence of hepatic or renal dysfunction, patients should be carefully monitored.

MINTEZOL should be used only in patients in whom susceptible worm infestation has been diagnosed and should not be used prophylactically.

Laboratory Tests

Rarely, a transient rise in liver function tests has occurred in patients receiving MINTEZOL.

Carcinogenesis, Mutagenesis, Impairment of Fertility

Thiabendazole has been used in numerous short- and long-term studies in animals at doses up to 15 times the usual human dose and was without carcinogenic effects. It did not adversely affect fertility in the mouse at 2% times the usual human dose or in the rat at a dose equivalent to the usual human dose. Thiabendazole had no mutagenic activity in in vitro microbial mutagen test, the micronucleus test and the host mediated assay in vivo.

Pregnancy

Pregnancy Category C: Reproduction and teratogenic studies done in the rabbit at a dose up to 15 times the usual human dose, in the rat at a dose equivalent to the human dose, and in the mouse at a dose up to 2% times the usual human dose, revealed no evidence of harm to the fetus. In an additional study in the mouse, no defects were observed when thiabendazole was given in aqueous suspension, at a dose 10 times the usual human dose; however, cleft palate and axial skeletal defects were observed when thiabendazole was suspended in olive oil and given at the same dose. There are no adequate and well controlled studies in pregnant women. MINTEZOL should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Nursing Mothers

It is not known whether this drug is excreted in human milk. Because of the potential for serious adverse reactions in nursing infants from MINTEZOL, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.

Pediatric Use

The safety and effectiveness of thiabendazole for the treatment of Strongyloidiasis, Ascariasis, Uncinariasis, Trichuriasis and Trichinosis in pediatric patients weighing less than 30 lbs has been limited.

Geriatric Use

Clinical studies of MINTEZOL did not include sufficient numbers of subjects aged 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. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.

This drug is metabolized almost completely by the liver, and the metabolites are known to be substantially excreted by the kidney, therefore the risk of toxicity may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function.

Overdosage may be associated with transient disturbances of vision and psychic alterations.

There is no specific antidote in the event of overdosage. Therefore, symptomatic and supportive measures should be employed. Emesis should be induced or gastric lavage performed carefully.

The oral LD₅₀ of MINTEZOL is 3.6 g/kg, 3.1 g/kg and 3.8 g/kg in the mouse, rat, and rabbit, respectively.

Hypersensitivity to this product.

Thiabendazole is contraindicated as prophylactic treatment for pinworm infestation.

In man, thiabendazole is rapidly absorbed and peak plasma concentration is reached within 1 to 2 hours after the oral administration of a suspension. It is metabolized almost completely to the 5-hydroxy form which appears in the urine as glucuronide or sulfate conjugates. In 48 hours, about 5% of the administered dose is recovered from the feces and about 90% from the urine. Most is excreted in the first 24 hours.

Mechanism of Action

The precise mode of action of thiabendazole on the parasite is unknown, but it may inhibit the helminth-specific enzyme fumarate reductase.

Thiabendazole is vermicidal and/or vermifugal against Ascaris lumbricoides ("common roundworm"), Strongyloides stercoralis (threadworm), Necator americanus, and Ancylostoma duodenale (hookworm), Trichuris trichiura (whipworm), Ancylostoma braziliense (dog and cat hookworm), Toxocara canis and Toxocara cati (ascarids), and Enterobius vermicularis (pinworm).

Its effect on larvae of Trichinella spiralis that have migrated to muscle is questionable.

Thiabendazole also suppresses egg and/or larval production and may inhibit the subsequent development of those eggs or larvae which are passed in the feces.

Because CNS side effects may occur quite frequently, activities requiring mental alertness should be avoided.

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.

THIABENDAZOLE - ORAL

(thigh-ah-BEN-dah-zole)

COMMON BRAND NAME(S): Mintezol

USES: This medication is used to treat roundworm infections such as threadworm, hookworm/creeping eruption (cutaneous larva migrans), and visceral larva migrans (toxocariasis).

This medication is also used for other types of roundworm infections such as pinworm, whipworm, large roundworm (ascariasis), and trichinosis when other therapies have failed or are unavailable.

HOW TO USE: This medication is generally taken by mouth, twice daily after meals, or as directed by your doctor. The tablet formulation must be chewed before swallowing. If taking the oral liquid, shake well before each dose. Your dosage is dependent upon your weight.

Cutaneous larva migrans may also be treated topically. Your pharmacist will prepare a lotion or ointment for you if so prescribed.

It is important that you take this medication for the prescribed duration. The duration of your therapy will depend on the type of infection and your response to treatment.

SIDE EFFECTS: Nausea, vomiting, loss of appetite, diarrhea, dizziness, drowsiness, or headache may occur. If any of these effects persist or worsen, notify your doctor 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 unlikely but serious side effects occur: seizures, tingling of hands/feet, mental/mood changes.

Tell your doctor immediately if any of these highly unlikely but very serious side effects occur: ringing in the ears, vision changes, stomach pain, yellowing eyes and skin, dark urine, fever, fatigue, increased thirst, change in the amount of urine.

A serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of an allergic reaction include: 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: This medication should not be used as prophylactic treatment for pinworms or any other worm infections.

This medication should not be used if you have a mixed infection with the Ascaris type of roundworm. This drug may cause the Ascaris worms to spread in your body, and possibly appear in your nose and mouth. Contact your doctor if this should occur.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: liver disease, kidney disease, anemia, dehydration, poor nutrition, any allergies.

This drug may make you dizzy or drowsy; use caution engaging in activities requiring alertness such as driving or using machinery. Limit alcoholic beverages.

Caution is advised when using this drug in the elderly because they may be more sensitive to the effects of the drug.

This medication should be used only when clearly needed during pregnancy. Discuss the risks and benefits with your doctor.

It is not known whether this drug passes into breast milk. Breast-feeding is not recommended while using this drug.

DRUG INTERACTIONS: Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription products you may use, especially of: theophylline.

Do not start or stop any medicine without doctor or pharmacist approval.

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. Canadian residents should call their local poison control center directly. Symptoms of overdose may include: vision changes or mental/mood changes.

NOTES: Do not share this medication with others.

Laboratory and/or medical tests may be performed to monitor your progress.

Practice strict personal hygiene to prevent reinfection. Wash hands with soap and clean under fingernails often. Change and wash undergarments, towels, bedsheets, and bedclothes daily.

MISSED DOSE: If you miss a dose, use 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 at room temperature between 59 and 86 degrees F (15 and 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.