• Basic Info
• Top Questions
• Interactions

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

Astemizole was withdrawn from the U.S. market in 1999.

Do not take astemizole (Hismanal) with any of the following medicines: antifungal drugs such as ketoconazole (Nizoral) and itraconazole (Sporanox); antibiotics such as erythromycin (E.E.S., E-Mycin, Ery-Tab), clarithromycin (Biaxin), and troleandomycin (TAO); the malaria medicine quinine (Quinamm); or the medicine nefazodone (Serzone). Take astemizole on an empty stomach, 1 hour before or 2 hours after eating food. Do not take astemizole with grapefruit or grapefruit juice. Grapefruit products may increase amount of astemizole available in your body, which could lead to dangerous side effects.

What is astemizole?

Astemizole was withdrawn from the U.S. market in 1999.

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

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

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

Who should not take astemizole?

You cannot take astemizole if you are taking any of the following medicines:

• an antifungal drug including ketoconazole (Nizoral) or itraconazole (Sporanox);

• an antibiotic including erythromycin (E.E.S., E-Mycin, Ery-Tab), clarithromycin (Biaxin), or troleandomycin (TAO);

• the malaria medicine quinine (Quinamm); or

• the medicine nefazodone (Serzone).

A dangerous side effect involving irregular heartbeats could occur if you take astemizole with any of the medicines listed above.

Before taking astemizole, tell your doctor if you have

• asthma or another lung disease;

• low potassium levels in your blood;

• urinary retention or an enlarged prostate;

• kidney disease;
• liver disease; or

• heart disease, especially an irregular heartbeat.

You may not be able to take astemizole, or you may require a dosage adjustment or special monitoring during treatment if you have any of the conditions listed above.

Astemizole is in the FDA pregnancy category C. This means that it is not known whether astemizole will harm an unborn baby. Do not take this medication without first talking to your doctor if you are pregnant. It is also not known whether astemizole passes into breast milk. Do not take astemizole without first talking to your doctor if you are breast-feeding a baby.

How should I take astemizole?

Take astemizole once a day as directed by your doctor. If you do not understand these instructions, ask your pharmacist, nurse, or doctor to explain them to you.

Take each dose with a full glass (8 ounces) of water. Take astemizole on an empty stomach, 1 hour before or 2 hours after a meal. Do not take astemizole with grapefruit or grapefruit juice. Grapefruit products may increase amount of astemizole available in your body, which could lead to dangerous side effects. Do not crush, chew, or break the tablets. Swallow them whole.

Never take more of this medication than is directed by your doctor. Larger than prescribed doses of astemizole may result in irregular heartbeats, and rarely, death. If your symptoms are not being adequately treated, talk to your doctor.

Store astemizole at room temperature away from moisture and heat.

What happens if I miss a dose?

Take the missed dose as soon as you remember. However, if it is almost time for your next dose, skip the missed dose and take only your next regularly scheduled dose. Do not take a double dose of this medication.

What happens if I overdose?

Seek emergency medical attention.

Symptoms of an astemizole overdose include headache, drowsiness, irregular heartbeats, nausea, and vomiting.