Karen Berger, PharmD, is a community pharmacist and medical writer/reviewer.
Femi Aremu, PharmD, is a professional pharmacist with experience in clinical and community pharmacy. He currently practices in Chicago, Illinois.
Zyrtec -D (cetirizine and pseudoephedrine ) is a combination medication used to temporarily relieve symptoms from hay fever, or allergies (e.g., sneezing; itchy nose, throat, and eyes; watery eyes; and a runny or stuffy nose).
Zyrtec-D blocks the effects of histamine (a substance produced in the body in response to allergens) and reduces swelling in the nasal passages to relieve sinus congestion and pressure, making it easier to breathe through the nose.
Note that Zyrtec-D is not the same as Zyrtec. Zyrtec is an over-the-counter (OTC) medication that only contains cetirizine (antihistamine). The D in Zyrtec-D stands for decongestant because it also includes the decongestant pseudoephedrine. This article will focus on Zyrtec-D. Zyrtec-D is available as an extended-release tablet that is taken by mouth.
Cetirizine is a second-generation antihistamine. Second-generation antihistamines cause less sedation (drowsiness) than first-generation antihistamines, such as Benadryl (diphenhydramine). As an antihistamine, cetirizine works by blocking the effects of histamine to reduce allergy symptoms.
Pseudoephedrine is a decongestant. It works by shrinking swollen nasal membranes, which helps reduce swelling and congestion and makes it easier to breathe through the nose.
Because it contains pseudoephedrine, Zyrtec-D must be sold from behind the pharmacy counter by law. Pseudoephedrine can be used to make methamphetamine (an illegal drug also known as meth). For this reason, people who purchase medications containing pseudoephedrine can only buy a certain amount each month and must show photo identification. Zyrtec-D does not require a prescription in most states, but some may require one.
Generic Name: Cetirizine and pseudoephedrine
Brand Name(s): Zyrtec-D
Drug Availability: Behind the pharmacy counter, subject to certain requirements and sale limitations
Therapeutic Classification: Antihistamine and decongestant
Controlled Substance: N/A
Active Ingredient: Cetirizine and pseudoephedrine
Dosage Form(s): Extended-release tablet
Zyrtec-D is used to temporarily relieve allergy/hay fever symptoms, including:
Read the information label and take it as directed. Do not take more than the appropriate dose.
For adults and adolescents 12 years or older, take one tablet every 12 hours. Do not exceed two tablets per day (24 hours). Swallow the tablet whole. Do not chew, crush, or break them.
One side effect of this medication is drowsiness, which can be enhanced by alcohol and other drugs used for sleep, anxiety, and severe pain. Avoid combining these substances and try not to do any activities that may be dangerous while experiencing drowsiness until you know Zyrtec-D will affect you.
Store Zyrtec-D at room temperature. Keep out of sight and reach of children and pets.
Zyrtec-D starts to relieve symptoms in about an hour. You may need to take Zyrtec-D regularly to keep allergy symptoms at bay. Ask your healthcare provider when you should start taking Zyrtec-D and how long you should take it. Many healthcare providers recommend starting allergy medicine about two weeks before symptoms are expected to begin.
This is not a complete list of side effects, and others may occur. A healthcare provider can advise you on side effects. If you experience other effects, contact your healthcare provider. You may report side effects to the Food and Drug Administration (FDA) at fda.gov/medwatch or 1-800-FDA-1088.
Like other medications, Zyrtec-D can cause side effects. Tell your healthcare provider about any side effects you experience while taking this medication. Side effects can occur from one or both ingredient(s) in Zyrtec-D.
Common side effects of Zyrtec-D include:
Call your healthcare provider right away if you have serious side effects. Call 911 if your symptoms feel life-threatening or if you think you’re having a medical emergency. Serious side effects and their symptoms can include:
While many people tolerate Zyrtec-D well, long-term or delayed side effects are possible. These may include:
Zyrtec-D may cause other side effects. Call your healthcare provider if you have any unusual problems while taking this medication.
If you experience a serious side effect, you or your healthcare provider may send a report to the FDA's MedWatch Adverse Event Reporting Program or by phone (800-332-1088).
The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
Swallow the extended-release tablet whole. Do not crush, break, or chew before swallowing.
Consult a healthcare provider about dosing:
People who are breastfeeding should not use Zyrtec-D.
If you miss a dose of Zyrtec-D, take it as soon as you remember. If it is almost time for the next dose, skip the missed dose. Do not double up on doses to make up for a missed dose.
Although Zyrtec-D is generally safe to take, it is possible to overdose if consumed in high amounts.
Overdoses have been reported with cetirizine alone. Doses ranging from 150 milligrams (mg) to 180 milligrams have been observed to cause adverse reactions in people. Signs that you have taken too much cetirizine can include:
The maximum dose of pseudoephedrine is:
Symptoms of a pseudoephedrine overdose can include, but are not limited to:
In children, signs of a pseudoephedrine overdose are more likely to include:
If you think you or someone else may have overdosed on Zyrtec-D, call a healthcare provider or the Poison Control Center (800-222-1222).
If someone collapses or isn't breathing after taking Zyrtec-D, call 911 immediately.
The antihistamine in this medicine will add to the effects of alcohol and other CNS depressants including tricyclic antidepressants (medicines that slow down the nervous system, possibly causing drowsiness). Some examples of CNS depressants are other antihistamines or medicine for hay fever, other allergies, or colds; sedatives, tranquilizers, or sleeping medicine; prescription pain medicine or narcotics; barbiturates; medicine for seizures; muscle relaxants; or anesthetics, including some dental anesthetics. Examples of Tricyclic antidepressants are amitriptyline [e.g. Elavil], amoxapine [e.g. Asendin], clomipramine [e.g. Anafranil], desipramine [e.g. Pertofrane], doxepine [e.g. Sinequan], imipramine [e.g. Tofranil], nortriptyline [e.g. Aventyl], protriptyline [Vivactil], trimipramine [e.g. Surmontil]. Check with your doctor before taking any of the above while you are taking this medicine.
The antihistamine in this medicine may cause some people to become drowsy, dizzy, or less alert than they are normally. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are dizzy or are not alert.
Antihistamines may cause dryness of the mouth, nose, and throat. For temporary relief, use sugarless candy or gum, melt bits of ice in your mouth, or use a saliva substitute. However, if your mouth continues to feel dry for more than 2 weeks, check with your dentist. Continuing dryness of the mouth may increase the chance of dental disease, including tooth decay, gum disease, and fungus infections.
The decongestant in this medicine may cause some people to be nervous or restless or to have trouble in sleeping. If you have trouble in sleeping, take the last dose of this medicine for each day a few hours before bedtime. If you have any questions about this, check with your doctor.
Zyrtec-D is not appropriate for everyone. You should not take this medication if allergic to cetirizine, pseudoephedrine, or any inactive ingredients in Zyrtec-D. People allergic to Vistaril (hydroxyzine) also should not take Zyrtec-D.
Others who should not take Zyrtec-D include those:
Zyrtec-D may be used cautiously in some people only if the healthcare provider determines it is safe. This includes those:
Tell your healthcare provider about all your medicines, including prescription drugs, OTC products, and vitamins or supplements.
Zyrtec-D should not be used with the following drugs because of the risk of severe high blood pressure:
Triptan medications, commonly prescribed for migraine, can also increase blood pressure and should only be used with Zyrtec-D if approved by your healthcare provider. Examples of triptans include Imitrex (sumatriptan) and Maxalt (rizatriptan).
Alcohol and drugs that cause CNS depression should not be taken with Zyrtec-D. Examples include:
Do not use Zyrtec-D with other antihistamines or decongestants.
Other drug interactions may occur with Zyrtec-D. Consult your healthcare provider for a complete list of drug interactions.
Zyrtec-D contains two ingredients: cetirizine and pseudoephedrine.
Cetirizine is a second-generation antihistamine that causes less drowsiness than first-generation antihistamines, such as Benadryl. Zyrtec (without the -D suffix) is an OTC antihistamine. It contains cetirizine without pseudoephedrine. Other OTC second-generation antihistamines include:
These single-ingredient antihistamines are available in a variety of formulations, such as oral tablets, dissolving tablets, and oral liquid.
Clarinex (desloratadine) is a second-generation antihistamine available by prescription.
Similar to Zyrtec-D, some of these are also available as a combination product with pseudoephedrine (and also kept behind the counter like Zyrtec-D):
Clarinex-D is available by prescription and contains desloratadine and pseudoephedrine.
Pseudoephedrine is also commonly known as Sudafed. However, due to the meth epidemic, several forms of Sudafed now exist. Sudafed (pseudoephedrine) products are available behind the pharmacy counter (and may need a prescription in some states). Sudafed PE contains a different decongestant called phenylephrine and is available OTC by itself and in many combination products for flu, cough, and cold.
The medication selection for these products can be extensive and overwhelming, so consult your pharmacist if you need help finding a product.
Zyrtec-D helps with symptoms of allergy and sinus congestion, such as runny or stuffy nose, itchy/watery eyes, and sneezing.
Zyrtec-D contains two ingredients. Cetirizine is an antihistamine. It blocks histamine, helping to prevent allergy symptoms. The second ingredient is pseudoephedrine, which is a decongestant. It helps shrink swollen nasal passages, reducing congestion and making it easier to breathe out of the nose.
Zyrtec-D interacts with various drugs, such as MAOI antidepressants, anxiety medications, triptans for migraine, and opioid pain medications. Alcohol also should not be mixed with Zyrtec-D. Before taking Zyrtec-D, ask your healthcare provider if it is safe for you to take with your other prescribed and OTC medications.
Zyrtec-D can start working as quickly as an hour. However, you may need to take it regularly to prevent allergy symptoms. Ask your healthcare provider when you should start (and stop) taking it.
Common side effects include stomach problems like stomach pain, nausea, vomiting, and diarrhea. Headache, drowsiness, and dizziness are also common side effects. Consult your healthcare provider for more information about side effects.
Pseudoephedrine can be made into the illegal drug methamphetamine (also known as meth). In response to the increasing use of illegal meth in the United States, Congress passed the Combat Methamphetamine Epidemic Act of 2005. This law was passed to prevent people from using pseudoephedrine to make meth. Because of this law, any medication that contains pseudoephedrine, including Zyrtec-D, must be sold behind the counter. This law also limits the amount of the medication any individual can purchase and requires photo identification.
In most states, Zyrtec-D does not require a prescription, but certain states may require a prescription.
Talk to your healthcare provider about the best treatment for allergies. It is helpful to see an allergist/immunologist, who can perform allergy testing, and recommend the best treatment for you. If you are at risk of a severe allergic reaction, be sure to carry an epinephrine injection everywhere you go. Wear a medical alert if you have ever had a serious allergic reaction.
In addition to taking Zyrtec-D, you can try some other nonmedicinal measures to prevent allergy symptoms:
Verywell Health's drug information is meant for educational purposes only and is not intended as a replacement for medical advice, diagnosis, or treatment from a healthcare provide. Consult your healthcare provide before taking any new medication(s). IBM Watson Micromedex provides some of the drug content, as indicated on the page.
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