Cetirizine vs Fexofenadine: Quick Guide to Picking the Best Allergy Pill

If you suffer from sneezing, itchy eyes or a runny nose, you’ve probably reached for an antihistamine. Two of the most popular over‑the‑counter options are cetirizine (Zyrtec) and fexofenadine (Allegra). Both promise fast relief, but they aren’t identical. Below we break down the key points so you can decide which one fits your day‑to‑day needs.

How They Work and What You Feel

Both drugs block histamine, the chemical your body releases when it spots an allergen. Cetirizine is a second‑generation antihistamine that starts working within 30‑60 minutes and can last up to 24 hours. Most people notice a drop in itching and sneezing quickly, but a small percentage feel a bit drowsy, especially at higher doses.

Fexofenadine also belongs to the second‑generation class, but it’s considered the least sedating of the lot. It kicks in in about an hour and keeps symptoms at bay for roughly 12‑24 hours. Because it doesn’t cross the blood‑brain barrier as much, you’re unlikely to feel sleepy, which makes it a popular choice for students, drivers, or anyone who needs to stay alert.

Choosing the Right One for You

Start by looking at your daily routine. If you need an antihistamine that won’t make you nod off during a meeting or a workout, fexofenadine is the safer bet. It’s also a good option for kids over 12 and for people who take medications that can interact with cetirizine, such as certain antidepressants.

On the other hand, cetirizine can be more affordable and is widely available in generic form. It works well for nighttime allergy relief because the mild drowsiness can actually help you sleep through symptoms. If you have a history of liver problems, check the dosage – cetirizine is processed by the liver, while fexofenadine is mainly excreted unchanged in the urine.

Both meds are taken once daily, but the exact dose matters. Adults typically use 10 mg of cetirizine or 180 mg of fexofenadine (once daily) for seasonal allergies. For kids, the dose is weight‑based, so read the label or ask a pharmacist.

Side‑effects are generally mild. Cetirizine can cause dry mouth, headache, or slight fatigue. Fexofenadine’s most common complaints are headache and occasional stomach upset. If you notice rash, swelling, or breathing trouble, stop the medication and seek help immediately – these are rare allergic reactions.

Lastly, think about price and access. Generic cetirizine often costs less than brand‑name fexofenadine, though many stores now carry a generic version of fexofenadine that’s competitively priced. Your local pharmacy or online UK‑based pharmacy can show you the current rates.

Bottom line: If you can tolerate a hint of drowsiness and want a budget‑friendly option, cetirizine is a solid choice. If you need to stay sharp and avoid any sleepiness, go with fexofenadine. Either way, follow the dosing instructions, keep an eye on how you feel, and talk to your doctor or pharmacist if you have any doubts.