What is Allerhist-1 (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.
What is the most important information I should know about Allerhist-1 (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 should I discuss with my healthcare provider before taking Allerhist-1 (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.
Allerhist-1 Side Effects
What are the possible side effects of Allerhist-1 (Clemastine)?
Stop taking clemastine and seek emergency medical attention if you experience an allergic reaction (difficulty breathing; closing of your throat; swelling of your lips, tongue, or face; or hives).
Other, less serious side effects may be more likely to occur. Continue to take clemastine and talk to your doctor if you experience
- sleepiness, fatigue, or dizziness
- headache
- dry mouth; or
- difficulty urinating or an enlarged prostate
Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome. You may report side effects to FDA at 1-800-FDA-1088.
Allerhist-1 Interactions
What other drugs affect Allerhist-1 (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.
Talk to your pharmacist before taking other over-the-counter cough, cold, allergy, or insomnia medications. These may contain medicines similar to clemastine, which could lead to an overdose of antihistamine.
Before taking this medication, tell your doctor if you are taking any of the following medicines:
- anxiety or sleep medicines such as alprazolam (Xanax), diazepam (Valium), chlordiazepoxide (Librium), temazepam (Restoril), or triazolam (Halcion)
- medications for depression such as amitriptyline (Elavil), doxepin (Sinequan), nortriptyline (Pamelor), fluoxetine (Prozac), sertraline (Zoloft), or paroxetine (Paxil); or
- any other medications that make you feel drowsy, sleepy, or relaxed
Drugs other than those listed here may also interact with clemastine. Talk to your doctor and pharmacist before taking any prescription or over-the-counter medicines.
What should I avoid while taking Allerhist-1 (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.
Allerhist-1 Dosage
How should I take Allerhist-1 (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 overdose on Allerhist-1 (Clemastine)?
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 happens if I miss a dose of Allerhist-1 (Clemastine)?
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.
Edited from everydayhealth.com