Taking Zyrtec With Mucinex Fast Max

Answer

You don't need to be worried. If you took Zyrtec and Mucinex Fast-Max six hours apart, the worst you are likely to experience is mild side effects, like added drowsiness and dry mouth.

While not all Mucinex Fast-Max products contain an antihistamine, some do. If the specific Mucinex product you are talking about does (e.g., Maximum Strength Fast-Max Night Cold & Flu), it will be a short-acting first-generation antihistamine, like doxylamine. It will wear off four to six hours after dosing.

Combining an antihistamine like Zyrtec and a sedating antihistamine like doxylamine shouldn't be done on a regular basis, but overall, you don't need to be too worried about side effects.

Mucinex Fast-Max products that don't already contain an antihistamine are considered safe to take with Zyrtec.

There Are Multiple Mucinex Fast-Max Products Available

Mucinex Fast-Max is a product line in which there are multiple versions intended to treat a variety of symptoms. Reviewing the ingredients of all the Fast-Max line of products, the nighttime varieties contain either diphenhydramine or doxylamine as an antihistamine.

Both of these are short-acting, first-generation antihistamines.

Antihistamine Overview

A quick lesson on antihistamines. There are two main families of antihistamines, first-generation and second-generation (some sources will list third-generation antihistamines, like levocetirizine, but those are commonly lumped into the second-generation).

First-generation antihistamines include drugs like

• Diphenhydramine (Benadryl)
• Doxylamine (Unisom, NyQuil)
• Chlorpheniramine (Chlor-Trimeton, Chlor-Tabs)

These drugs block histamine receptors in both the brain and the rest of the body; they also interact with several other receptor types. This makes them good at relieving allergy symptoms, but also gives them a few unpleasant side effects, particularly sedation/drowsiness, dry mouth, and dry eyes.

Second-generation antihistamines include drugs like:

• Cetirizine (Zyrtec)
• Fexofenadine (Allegra)
• Desloratadine (Clarinex)
• Loratadine (Claritin)

These drugs, unlike the first-generation ones, are designed so that they can’t cross the barrier that protects the brain from harmful chemicals in your blood. The result is they can only block histamine receptors found in the rest of your body, and not in the brain, so they produce allergy relief with much less drowsiness and other side effects.

That said, this doesn’t mean they can’t make you drowsy, and taking them with other antihistamines, alcohol, or drugs that affect the central nervous system (bupropion, benzodiazepines like alprazolam or clonazepam, and others) can produce substantial additive effects that could impair your ability to make decisions or operate a vehicle.

Combining Antihistamines

 Again, mixing different types of antihistamines should be avoided if possible, but there are cases where your doctor may recommend using both for specific situations (such as one in the morning for seasonal allergies and one in the evening on an 'as-needed' basis for help sleeping).

Combining Zyrtec and the antihistamine in Mucinex Fast-Max (i.e., doxylamine) may cause you to feel more drowsy than usual, but, doxylamine only lasts for a few hours.

You should be sure not to partake in any activities that require attention, however, like driving a car.

Final Words

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