"Dec. 24, 2012 -- Colorado Springs high school junior Morgan Smith can't remember a time when he didn't have life-threatening food allergies.
The 16-year-old had his first reaction to peanut butter at 9 months of age when he broke out in hiv"...
(Generic versions may still be available.)
QT PROLONGATION/ VENTRICULAR ARRHYTHMIAS
RARE CASES OF SERIOUS CARDIOVASCULAR ADVERSE EVENTS INCLUDING DEATH, CARDIAC ARREST, QT PROLONGATION, TORSADES DE POINTES, AND OTHER VENTRICULAR ARRHYTHMIAS HAVE BEEN OBSERVED IN PATIENTS EXCEEDING RECOMMENDED DOSES OF ASTEMIZOLE. WHILE THE MAJORITY OF SUCH EVENTS HAVE OCCURRED FOLLOWING SUBSTANTIAL OVERDOSES OF ASTEMIZOLE, TORSADES DE POINTES (ARRHYTHMIAS) HAVE VERY RARELY OCCURRED AT REPORTED DOSES AS LOW AS 20- 30 MG DAILY (2- 3 TIMES THE RECOMMENDED DAILY DOSE).
DATA SUGGEST THAT THESE EVENTS ARE ASSOCIATED WITH ELEVATION OF ASTEMIZOLE AND/ OR ASTEMIZOLE METABOLITE LEVELS, RESULTING IN ELECTROCARDIOGRAPHIC QT PROLONGATION. THESE EVENTS HAVE ALSO OCCURRED AT 10 MG DAILY IN A FEW PATIENTS WITH POSSIBLE AUGMENTING CIRCUMSTANCES (SEE CONTRAINDICATIONS AND WARNINGS). IN VIEW OF THE POTENTIAL FOR CARDIAC ARRHYTHMIAS, ADHERENCE TO THE RECOMMENDED DOSE SHOULD BE EMPHASIZED. DO NOT EXCEED THE RECOMMENDED DOSE OF 10 MG (ONE TABLET) DAILY. SOME PATIENTS APPEAR TO INCREASE THE DOSE OF HISMANAL (ASTEMIZOLE) TABLETS IN AN ATTEMPT TO ACCELERATE THE ONSET OF ACTION. PATIENTS SHOULD BE ADVISED NOT TO DO THIS AND NOT TO USE HISMANAL (astemizole withdrawn from us market) Ò® ON AN AS- NEEDED BASIS (I. E., P R N) FOR IMMEDIATE RELIEF OF SYMPTOMS.
CONCOMITANT ADMINISTRATION OF ASTEMIZOLE WITH SYSTEMIC KETOCONAZOLE, TRACONAZOLE, ERYTHROMYCIN, CLARITHROMYCIN, TROLEANDOMYCIN, MIBEFRADIL OR QUININE IS CONTRAINDICATED (SEE CONTRAINDICATIONS AND PRECAUTIONS: DRUG INTERACTIONS). SINCE ASTEMIZOLE IS EXTENSIVELY METABOLIZED BY THE LIVER, THE USE OF ASTEMIZOLE IN PATIENTS WITH HEPATIC DYSFUNCTION IS CONTRAINDICATED. IN SOME CASES, SEVERE ARRHYTHMIAS HAVE BEEN PRECEDED BY EPISODES OF SYNCOPE. SYNCOPE IN PATIENTS RECEIVING ASTEMIZOLE SHOULD LEAD TOIMMEDIATE DISCONTINUATION OF TREATMENT AND APPROPRIATE CLINICAL EVALUATION, INCLUDING ELECTRO- CARDIOGRAPHIC TESTING (LOOKING FOR QTPROLONGATION AND VENTRICULAR ARRHYTHMIA). (SEE CLINICAL PHARMACOLOGY, CONTRAINDICATIONS, WARNINGS, PRECAUTIONS, OVERDOSAGE, AND DOSAGE AND ADMINISTRATION.)
Hismanal (astemizole) is a histamine H1-receptor antagonist available in scored white tablets for oral use. Each tablet contains 10 mg of astemizole, and as inactive ingredients: lactose, cornstarch, microcrystalline cellulose, pregelatinized starch, povidone K90, magnesium stearate, colloidal silicon dioxide, and sodium lauryl sulfate. Astemizole is chemically designated as 1-[(4-fluorophenyl) -methyl] -N-[1-[2-(4-methoxyphenyl) ethyl]-4 -piperidinyl]-1H-benzimidazol-2-amine, with a molecular weight of 458.58. The empirical formula is C28H31FN4O.
Astemizole is a white to slightly off-white powder; it is insoluble in water, slightly soluble in ethanol and soluble in chloroform and methanol.
Last reviewed on RxList: 12/8/2004
This monograph has been modified to include the generic and brand name in many instances.
Additional Hismanal Information
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