Vandazole Drug Information

VANDAZOLE ® is indicated in the treatment of bacterial vaginosis (formerly referred to as Haemophilus vaginitis, Gardnerella vaginitis, nonspecific vaginitis, Corynebacterium vaginitis, or anaerobic vaginosis) in post-menarchal females. VANDAZOLE is a nitroimidazole antimicrobial indicated for the treatment of bacterial vaginosis in post-menarchal females.

The recommended dose is one applicator full of VANDAZOLE, (approximately 5 grams of gel containing approximately 37.5 mg of metronidazole) administered intravaginally once a day for 5 days. For once a day dosing, VANDAZOLE should be administered at bedtime. Not for ophthalmic, dermal, or oral use.

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The data described below reflect exposure to VANDAZOLE compared to another formulation of vaginal metronidazole in 220 women in a single trial. Patients administered an applicator full of VANDAZOLE intravaginally once daily at bedtime for 5 days.

There were no deaths or serious adverse reactions related to drug therapy in the clinical trial. VANDAZOLE was discontinued in 5 patients (2.3%) due to adverse reactions. The incidence of all adverse reactions in VANDAZOLE-treated patients was 42% (92/220).

Approximately 10% of patients treated with VANDAZOLE developed Candida vaginitis during or immediately after therapy. Additional uncommon events, reported by < 1% of those women treated with VANDAZOLE included:

Other Metronidazole Formulations Other Vaginal Formulations

Other reactions that have been reported in association with the use of other formulations of metronidazole vaginal gel include: unusual taste and decreased appetite. Topical (Dermal) Formulations Other reactions that have been reported in association with the use of topical (dermal) formulations of metronidazole include skin irritation, transient skin erythema, and mild skin dryness and burning. None of these adverse reactions exceeded an incidence of 2% of patients.

Oral and Parenteral Formulations The following adverse reactions and altered laboratory tests have been reported with the oral or parenteral use of metronidazole: Cardiovascular: Flattening of the T-wave may be seen in electrocardiographic tracings. Nervous System: The most serious adverse reactions reported in patients treated with metronidazole have been convulsive seizures, encephalopathy, aseptic meningitis, optic and peripheral neuropathy, the latter characterized mainly by numbness or paresthesia of an extremity. In addition, patients have reported syncope, vertigo, incoordination, ataxia, confusion, dysarthria, irritability, depression, weakness, and insomnia.

Gastrointestinal: Abdominal discomfort, nausea, vomiting, diarrhea, an unpleasant metallic taste, anorexia, epigastric distress, abdominal cramping, constipation, “furry” tongue, glossitis, stomatitis, pancreatitis, and modification of taste of alcoholic beverages. Genitourinary: Overgrowth of Candida in the vagina, dyspareunia, decreased libido, proctitis. Hematopoietic: Reversible neutropenia, reversible thrombocytopenia.

Hypersensitivity Reactions: Urticaria; erythematous rash; Stevens-Johnson Syndrome, toxic epidermal necrolysis, flushing; nasal congestion; dryness of the mouth, vagina, or vulva; fever; pruritus; fleeting joint pains. Renal: Dysuria, cystitis, polyuria, incontinence, a sense of pelvic pressure, darkened urine.

Disulfiram Use of oral metronidazole has been associated with psychotic reactions in alcoholic patients who are using disulfiram concurrently. VANDAZOLE should not be used by patients who have taken disulfiram within the last two weeks.

Alcoholic Beverages Use of oral metronidazole has been associated with a disulfiram-like reaction (abdominal cramps, nausea, vomiting, headaches, and flushing) to alcohol. Alcoholic beverages and preparations containing ethanol or propylene glycol should not be consumed during and for at least three days after VANDAZOLE therapy.

Coumarin and Other Oral Anticoagulants Use of oral metronidazole has been reported to potentiate the anticoagulant effect of warfarin and other coumarin anticoagulants, resulting in a prolongation of prothrombin time. This possible drug interaction should be considered when VANDAZOLE is prescribed for patients on this type of anticoagulant therapy. In patients on oral anticoagulants, consider monitoring prothrombin time, international normalized ratio (INR), and other coagulation parameters while on VANDAZOLE.

Lithium

Short-term use of oral metronidazole has been associated with elevation of serum lithium concentrations and, in a few cases signs of lithium toxicity, in patients stabilized on relatively high doses of lithium. Use VANDAZOLE with caution in patients treated with lithium and consider monitoring lithium serum concentrations while on VANDAZOLE.

Cimetidine Use of oral metronidazole with cimetidine may prolong the half-life and decrease plasma clearance of metronidazole. No dose adjustment of VANDAZOLE is necessary.

Pregnancy Risk Summary Available data on metronidazole use in pregnant women from published cohort studies, case-control studies, case series, meta analyses, and case reports over several decades have not established a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes. In animal reproduction studies, no adverse developmental effects were demonstrated when oral metronidazole was administered to mice at doses up to six times the recommended human dose (see Data). The estimated background risk of major birth defects and miscarriage for the indicated population is unknown.

All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is respectively. Many studies included first trimester exposures.

One study showed an increased risk of cleft lip, with or without cleft palate, in infants exposed to metronidazole in-utero; however, these findings were not confirmed. Most studies did not show an increased risk for congenital anomalies or other adverse fetal outcomes following metronidazole exposure during pregnancy. Studies conducted to assess the risk of infant cancer following systemic metronidazole exposure during pregnancy did not show an increased risk; however, the ability of these studies to detect such a signal was limited.

Animal Data Animal studies have shown that metronidazole crosses the placental barrier and enters the fetal circulation rapidly. Oral metronidazole reproductive toxicity studies have been performed in mice at doses up to six times the recommended human dose based on body surface area comparisons and have revealed no evidence of harm to the fetus. However, in a single small study where the drug was administered intraperitoneally, some intrauterine deaths were observed.

Pediatric Use The safety and efficacy of VANDAZOLE in the treatment of bacterial vaginosis in post-menarchal females have been established on the extrapolation of clinical trial data from adult females. The safety and efficacy of VANDAZOLE in pre-menarchal females have not been established.

Hypersensitivity

The use of VANDAZOLE is contraindicated in patients with a history of hypersensitivity to metronidazole, other nitroimidazole derivatives, or parabens. Reported reactions include urticaria; erythematous rash; Stevens-Johnson Syndrome, toxic epidermal necrolysis, flushing; nasal congestion; dryness of the mouth, vagina, or vulva; fever; pruritus; fleeting joint pains.

Psychotic Reaction with Disulfiram Use of oral metronidazole is associated with psychotic reactions in alcoholic patients who were using disulfiram concurrently. Do not administer VANDAZOLE to patients who have taken disulfiram within the last two weeks.

Interaction with Alcohol Use of oral metronidazole is associated with a disulfiram-like reaction to alcohol, including abdominal cramps, nausea, vomiting, headaches, and flushing. Discontinue alcohol consumption during and for at least three days after therapy with VANDAZOLE.

There is no human experience with overdosage of metronidazole vaginal gel. Vaginally applied metronidazole gel, 0.75% could be absorbed in sufficient amounts to produce systemic effects.