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

• Use caution when driving, operating machinery, or performing other hazardous activities. Periactin 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 Periactin.

What is Periactin?

• Periactin is an antihistamine. Periactin blocks the effects of the naturally occurring chemical histamine in your body.
• Periactin is used to treat sneezing; runny nose; itching, watery eyes; hives; rashes; itching; and other symptoms of allergies and the common cold.
• Although not approved by the FDA for this purpose, Periactin has been used to stimulate appetite in underweight patients.
• Periactin may also be used for purposes other than those listed in this medication guide.

Who should not take Periactin?

• Do not take Periactin 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 Periactin, or you may require a lower dose or special monitoring during treatment if you have any of the conditions listed above.
• Periactin is in the FDA pregnancy category B. This means that it is unlikely to harm an unborn baby. Do not take Periactin without first talking to your doctor if you are pregnant.
• Periactin passes into breast milk. Infants are especially sensitive to the effects of antihistamines, and serious side effects could occur in a nursing baby. Periactin is not recommended if you are breast-feeding a baby. Do not take Periactin 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 Periactin. You may require a lower dose of this medication.

How should I take Periactin?

• Take Periactin 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.
• Periactin can be taken with or without food.
• To ensure that you get a correct dose, measure the syrup form of Periactin 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 Periactin that you should take in 1 day is 32 mg.
• Store Periactin 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 Periactin 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 Periactin?

• Use caution when driving, operating machinery, or performing other hazardous activities. Periactin 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 Periactin.

What are the possible side effects of Periactin?

• Stop taking Periactin 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 Periactin 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.

What other drugs will affect Periactin?

• Do not take Periactin 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 products may contain medicines similar to Periactin, 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 Periactin. Talk to your doctor and pharmacist before taking any prescription or over-the-counter medicines.