In this Article

• What is astemizole (Hismanal)?
• What are the possible side effects of astemizole (Hismanal)?
• What is the most important information I should know about astemizole (Hismanal)?
• Who should not take astemizole (Hismanal)?
• How should I take astemizole (Hismanal)?
• What happens if I miss a dose (Hismanal)?
• What happens if I overdose (Hismanal)?
• What should I avoid while taking astemizole (Hismanal)?
• What other drugs will affect astemizole (Hismanal)?
• Where can I get more information?

Who should not take astemizole (Hismanal)?

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 (Hismanal)?

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.