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

Use caution when driving, operating machinery, or performing other hazardous activities. Clemastine may cause dizziness or drowsiness. If you experience dizziness or drowsiness, avoid these activities. Use alcohol cautiously. Alcohol may increase drowsiness and dizziness while you are taking clemastine.

What is clemastine?

Clemastine is an antihistamine. Clemastine blocks the effects of the naturally occurring chemical histamine in your body.

Clemastine is used to treat sneezing, runny nose, itching watery eyes, hives, rashes, itching, and other symptoms of allergies and the common cold.

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

Who should not take clemastine?

Do not take clemastine if you have taken a monoamine oxidase inhibitor (MAOI) such as isocarboxazid (Marplan), phenelzine (Nardil), or tranylcypromine (Parnate) in the last 14 days. A very dangerous drug interaction could occur, leading to serious side effects.

Before taking this medication, tell your doctor if you have

• glaucoma or increased pressure in the eye;

• a stomach ulcer;

• an enlarged prostate, bladder problems, or difficulty urinating;

• an overactive thyroid (hyperthyroidism);

• hypertension or any type of heart problems; or

• asthma.

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

Clemastine is in the FDA pregnancy category B. This means that it is unlikely to harm an unborn baby. Do not take clemastine without first talking to your doctor if you are pregnant. Clemastine passes into breast milk. Infants are especially sensitive to the effects of antihistamines, and serious side effects could occur in a nursing baby. Clemastine is not recommended if you are breast-feeding a baby. Do not take clemastine without first talking to your doctor if you are nursing a baby. If you are over 60 years of age, you may be more likely to experience side effects from clemastine. You may require a lower dose of this medication.

How should I take clemastine?

Take clemastine exactly as directed by your doctor. If you do not understand these directions, ask your pharmacist, nurse, or doctor to explain them to you.

Take each dose with a full glass of water.

Clemastine can be taken with or without food.

To ensure that you get a correct dose, measure the syrup form of clemastine with a special dose-measuring spoon or cup, not with a regular tablespoon. If you do not have a dose-measuring device, ask your pharmacist where you can get one.

Never take more of this medication than is prescribed for you. The maximum amount of clemastine that you should take in 1 day is 8.04 mg.

Store clemastine 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 unless otherwise directed by your doctor.

What happens if I overdose?

Seek emergency medical attention.

Symptoms of a clemastine overdose include extreme sleepiness, confusion, weakness, ringing in the ears, blurred vision, large pupils, dry mouth, flushing, fever, shaking, insomnia, hallucinations, and possibly seizures.

What should I avoid while taking clemastine?

Use caution when driving, operating machinery, or performing other hazardous activities. Clemastine may cause dizziness or drowsiness. If you experience dizziness or drowsiness, avoid these activities. Use alcohol cautiously. Alcohol may increase drowsiness and dizziness while you are taking clemastine.