If you’ve got seasonal allergies, you’ve likely heard of Zyrtec (cetirizine), an over-the-counter antihistamine. However, if you’re already taking Xanax (alprazolam) for an anxiety or panic disorder, you should consult your prescriber before also taking Zyrtec. The combination of both medications may result in compounding side effects.
Zyrtec and Xanax Interactions: Increased Drowsiness and Fatigue
Zyrtec is commonly used to temporarily relieve allergy symptoms, such as sneezing, runny nose and itchy nose or throat. As its antihistamine classification suggests, Zyrtec inhibits allergy-inducing histamines, chemicals within the body that cause allergy symptoms.
Primary side effects of Zyrtec include drowsiness and fatigue, which can make tasks like concentrating or driving challenging.
The reason for these primary side effects is Zyrtec’s ability to cross the blood-brain barrier, a membrane that protects the central nervous system. Medications that can cross this barrier affect brain activity and may cause drowsiness. Antihistamines are a class of drugs that cross the blood-brain barrier to differing degrees, causing drowsiness that varies in intensity.
“While Zyrtec is less sedating than first-generation antihistamines like diphenhydramine [Benadryl], Zyrtec still has mild sedative effects,” says Sireesha Kolli, M.D., board-certified psychiatrist and founder of Kolli Psychiatric & Associates in New Jersey.
This risk of drowsiness can become more of a concern when Zyrtec is combined with benzodiazepines like Xanax, which are often prescribed to manage anxiety and panic disorders. Xanax binds to gamma-aminobutyric acid (GABA) receptors. GABA is a neurotransmitter that inhibits nervous system activity. When Xanax binds to GABA receptors, it enhances GABA’s ability to bind to those receptors as well, amplifying GABA’s calming effects, explains Dr. Kolli. Central nervous system inhibition is key to Xanax’s effectiveness in treating anxiety, as it produces a relaxing effect in the brain. However, this mechanism also causes drowsiness and sedation.
“When taken together, [Xanax and Zyrtec] can have additive sedative effects, leading to increased drowsiness, fatigue, and reduced mental alertness,” says Dr. Kolli.
For most people, this sedative effect is not generally considered dangerous, explains Dr. Kolli. But it may impair someone’s ability to perform tasks that require focus, such as studying, driving or operating machinery. The combination of these two medications may pose a greater risk for individuals who are sensitive to sedative effects (such as older individuals) or who have underlying health conditions, Dr. Kolli adds. Because of this, it’s best to consult your doctor before taking Zyrtec with Xanax.
What Are the Best Non-Drowsy Alternatives to Zyrtec?
For individuals taking Xanax and looking for allergy relief, Dr. Kolli suggests trying less sedating antihistamines to help reduce the risk of excessive drowsiness or sedation. Possible alternatives might include Claritin (loratadine) and Allegra (fexofenadine), as both cross the blood-brain barrier to a lesser degree than Zyrtec and are less likely to cause sedation.
“Non-sedating options allow patients to manage their allergy symptoms while preserving cognitive and motor abilities, which is especially important for those who need to remain alert,” Dr. Kolli says.
Additionally, natural alternatives to help treat allergies, such as saline rinses and the use of antioxidants such as quercetin, may be viable options for a wide variety of people.
Check out two more articles in our interaction series: Can I Take Benadryl With Zoloft? and Can I Take Ibuprofen With Prednisone?
