Hisnot

Hisnot is a long-acting, non-sedating second generation antihistamine used in the treatment of allergy symptoms. It was withdrawn from market by the manufacturer in 1999 due to the potential to cause arrhythmias at high doses, especially when when taken with CYP inhibitors or grapefruit juice.

Hisnot tablets are indicated for the relief of symptoms associated with seasonal allergic rhinitis and chronic idiopathic urticaria. Hisnot should not be used as a p r n product for immediate relief of symptoms. Patients should be advised not to increase the dose in an attempt to accelerate the onset of action.

Clinical studies have not been conducted to evaluate the effectiveness of Hisnot in the common cold.

Hisnot was withdrawn from the U.S. market in 1999.

Hisnot is an antihistamine. Antihistamines prevent sneezing, runny nose, itching and watering of the eyes, and other allergic symptoms.

Hisnot is used to treat allergies, hives (urticaria), and other allergic inflammatory conditions.

Hisnot may also be used for purposes other than those listed in this medication guide.

The recommended dosage for adults and children 12 years of age and older is 10 mg (1 tablet) once daily.

Patients should be advised not to increase the dose of Hisnot in an attempt to accelerate the onset of action.

Use of Hisnot in patients taking ketoconazole, itraconazole, or erythromycin is contraindicated

Studies evaluating the need for dosage adjustments for patients with hepatic or renal dysfunction have not been performed. Since Hisnot is extensively metabolized by the liver, use of Hisnot in patients with significant hepatic dysfunction should generally be avoided.

Hisnot should be taken in an empty stomach, e.g., at least two hours after a meal. There should be no additional food intake for at least one hour post-dosing.

How supplied

Hisnot is available as white, scored tablets containing 10 mg of Hisnot debossed "JANSSEN" and on the reverse side debossed "AST/10."

Storage: Store tablets at room temperature (59°-86°) (15°- 30°C). Protect from moisture.

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What is the most important information I should know about Hisnot?

Concomitant administration of Hisnot with erythromycin is contraindicated because erythromycin is known to impair the cytochrome P450 enzyme system which also influences Hisnot metabolism. There have been two reports to date of syncope with Torsades De Pointes, requiring hospitalization, in patients taking combinations of Hisnot 10 mg daily with erythromycin. In each case the QT intervals were prolonged beyond 650 milliseconds the time of the event; One patient also received ketoconazole and the other patient also had hypokalemia.

Concomitant administration of Hisnot with ketoconazole tablets is contraindicated because available human pharmacokinetic data indicate that oral ketoconazole significantly inhibits the metabolism of Hisnot, resulting in elevated plasma levels of Hisnot and desmethylastemizole. Data suggest that cardiovascular events are associated with elevation of Hisnot and/or Hisnot metabolite levels resulting in electrocardiographic QT prolongation.

Concomitant administration with itraconazole is also contraindicated based on the chemical resemblance of itraconazole and ketoconazole. In vitro data suggest that itraconazole has a less pronounced effect on the biotransformation system responsible for the metabolism of Hisnot compared to ketoconazole.

Hisnot is contraindicated in patients with known hypersensitivity to Hisnot or any of the inactive ingredients.

Hisnot is used in the treatment of allergic conditions causing runny nose (rhinitis), redness and watering of eyes (conjunctivitis), skin rashes (urticaria), and allergic reactions to drugs and food. However, it has been withdrawn from the market due to adverse effects on the heart rhythm (QT prolongation).

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What other drugs will affect Hisnot?

Ketoconazole/Itraconazole: Concomitant administration of ketoconazole tablets or itraconazole with Hisnot is contraindicated.

Due to the chemical similarity of fluconazole, metronidazole, and miconazole IV to ketoconazole, concomitant use of these products is not recommended.

Macrolides (Including Erythromycin): Concomitant administration of erythromycin with Hisnot is contraindicated. Concomitant administration of Hisnot with other macrolide antibiotics, including troleandomycin, azithromycin, and clarithromycin, is not recommended.

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What are the possible side effects of Hisnot?

For information regarding cardiovascular adverse events (e.g., cardiac arrest, ventricular arrhythmias), please see CONTRAINDICATIONS and WARNINGS. In some cases, recognition of severe arrhythmias has been preceded by episodes of syncope. Similarly, rare cases of hypotension, palpitations, and dizziness have also been reported with Hisnot use, which may reflect undetected ventricular arrhythmia.

In studies the usual maintenance dose of Hisnot was 10 mg once daily.

TABLE 1 - Hisnot, Adverse Reactions Percent of Patients Reporting Controlled Studies*

Adverse reaction information has been obtained from more than 7500 patients in all clinical trials. Weight gain has been reported in 3.6% of Hisnot treated patients involved in controlled studies, with an average treatment duration of 53 days. In 46 of the 59 patients for whom actual weight gain data was available, the average weight gain was 3.2 kg.

Less frequently occurring adverse experiences reported in clinical trials or spontaneously from marketing experience with Hisnot include: angioedema, asymptomatic liver enzyme elevations, bronchospasm, depression, edema, epistaxis, myalgia, palpitation, paresthesia, photosensitivity, pruritus, and rash.

Marketing experiences include isolated cases of convulsions. A causal relationship with Hisnot has not been established.