Diphenhydramine and phenylephrine

What is the most important information I should know about diphenhydramine and phenylephrine?

Use caution when driving, operating machinery, or performing other hazardous activities. Diphenhydramine and phenylephrine 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 diphenhydramine and phenylephrine.

What is diphenhydramine and phenylephrine?

Diphenhydramine is an antihistamine. It blocks the effects of histamine in the body and reduces sneezing; itchy, watery eyes and nose; and other symptoms of allergies and hay fever.

Phenylephrine is a decongestant. It works by constricting (shrinking) blood vessels (veins and arteries) in the body. Constriction of blood vessels in the sinuses and nose decreases congestion.

Diphenhydramine and phenylephrine is used to treat nasal congestion and sinusitis (inflammation of the sinuses) associated with allergies, hay fever, and the common cold.

Diphenhydramine and phenylephrine may also be used for purposes other than those listed in this medication guide.

What should I discuss with my healthcare provider before taking diphenhydramine and phenylephrine?

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

Before taking this medication, tell your doctor if you have

• epilepsy or another seizure disorder;
• been diagnosed with sleep apnea (periods of not breathing during sleep);
• thyroid problems;
• asthma, emphysema, or chronic obstructive pulmonary disease (COPD);
• gallbladder disease;
• a head injury;
• Addison's disease;
• diabetes;
• glaucoma;
• an ulcer or an obstruction in the stomach;
• bladder problems or difficulty urinating;
• an enlarged prostate;
• high blood pressure, irregular heartbeats, or any type of heart disease;
• kidney problems; or
• liver problems.

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

It is not known whether diphenhydramine and phenylephrine will be harmful to an unborn baby. Do not take this medication without first talking to your doctor if you are pregnant or could become pregnant during treatment.

This medication may pass into breast milk and be harmful to a nursing infant. Do not take this medication without first talking to your doctor if you are breast-feeding a baby.

If you are over 60 years of age, you may be more likely to experience side effects from diphenhydramine and phenylephrine. Your doctor may prescribe a lower dose of this medication.

Consult your doctor or pharmacist before treating a child with this medication. Children are more susceptible than adults to the effects of medicines and may have unusual reactions. Read the package label for directions for use in children.

How should I take diphenhydramine and phenylephrine?

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

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

Do not take more of this medication than is recommended. An overdose of this medication can cause serious harm.

Do not take diphenhydramine and phenylephrine for longer than is prescribed. If your symptoms do not improve, if they get worse, or if they are accompanied by fever, talk to your doctor.

Store diphenhydramine and phenylephrine 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 the next dose, skip the missed dose and take only the next regularly scheduled dose. Do not take a double dose of this medication.

What happens if I overdose?

Seek emergency medical attention if an overdose is suspected.

Symptoms of a diphenhydramine and phenylephrine overdose may include dryness of the mouth, large pupils, flushing, nausea, vomiting, hyperactivity, or hallucinations.

What should I avoid while taking diphenhydramine and phenylephrine?

Use caution when driving, operating machinery, or performing other hazardous activities. Diphenhydramine and phenylephrine 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 diphenhydramine and phenylephrine.

Do not take other over-the-counter cough, cold, allergy, diet, or sleep aids while taking diphenhydramine and phenylephrine without first talking to your doctor or pharmacist. Other medications may also contain diphenhydramine, phenylephrine or other similar drugs. You may accidentally take too much of these medicines.

Diphenhydramine and phenylephrine may increase the effects of other drugs that cause drowsiness, including antidepressants, alcohol, other antihistamines, pain relievers, anxiety medicines, seizure medicines, and muscle relaxants. Dangerous sedation, dizziness, or drowsiness may occur if diphenhydramine and phenylephrine is taken with any of these medications.

What are the possible side effects of diphenhydramine and phenylephrine?

If you experience any of the following uncommon but serious side effects, stop taking diphenhydramine and phenylephrine and seek emergency medical attention or contact your doctor immediately:

• an allergic reaction (difficulty breathing; closing of the throat; swelling of the lips, tongue, or face; or hives); or
• confusion, hallucinations, or unusual behavior.

Other, less serious side effects may be more likely to occur. Continue to take diphenhydramine and phenylephrine and talk to your doctor if you experience

• dryness of the eyes, nose, and mouth;
• drowsiness or dizziness;
• blurred vision;
• difficulty urinating; or
• excitation in children.

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 diphenhydramine and phenylephrine?

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

Do not take other over-the-counter cough, cold, allergy, diet, or sleep aids while taking diphenhydramine and phenylephrine without first talking to your doctor or pharmacist. Other medications may also contain diphenhydramine, phenylephrine or other similar drugs. You may accidentally take too much of these medicines.

Diphenhydramine and phenylephrine may increase the effects of other drugs that cause drowsiness, including antidepressants, alcohol, other antihistamines, pain relievers, anxiety medicines, seizure medicines, and muscle relaxants. Dangerous sedation, dizziness, or drowsiness may occur if diphenhydramine and phenylephrine is taken with any of these medications.

Drugs other than those listed here may also interact with diphenhydramine and phenylephrine. Talk to your doctor and pharmacist before taking any prescription or over-the-counter medicines, including vitamins, minerals, and herbal products.

Where can I get more information?

Your pharmacist has additional information about diphenhydramine and phenylephrine written for health professionals that you may read.

What does my medication look like?

Diphenhydramine and phenylephrine is available with a prescription under the brand name Dytan-D. Other brand or generic formulations may also be available. Ask your pharmacist any questions you have about this medication, especially if it is new to you.

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2003 Cerner Multum, Inc. Version: 1.03. Revision date: 2/13/04.