Allecet contains cetirizine dihydrochloride 10 mg, a once-daily non-sedating antihistamine. It treats hay fever, allergic rhinitis, itchy watery eyes, hives and allergic itching. It causes far less drowsiness than older antihistamines, though a minority of people still notice it.

What is Allecet?

Allecet contains cetirizine dihydrochloride 10 mg, a second-generation antihistamine.

An allergic reaction begins when the immune system treats something harmless — pollen, dust mite, mould, animal dander — as a threat. Mast cells release histamine, and histamine acting on H1 receptors produces the familiar cluster: sneezing, a runny itchy nose, watery eyes, and in the skin, weals and itching. Cetirizine occupies those receptors so histamine cannot bind.

The generation matters. Older antihistamines such as the chlorphenamine in Rhineton cross readily into the brain, where the same receptors govern wakefulness, and cause pronounced drowsiness. Cetirizine was designed to cross far less — which is what makes a once-daily antihistamine workable for someone who has to drive, work or study.

Cetirizine sits at a useful point within that group. It is among the more effective second-generation antihistamines, particularly for itching, though it sedates slightly more than loratadine or fexofenadine. For most people that trade favours cetirizine; for a minority it does not.

The same ingredient is sold as Austell Cetirizine, Seasoneze, Zyrtec and Texa.

What is Allecet commonly used for?

Allecet is used for allergic conditions:

For hives, cetirizine deserves particular mention. Chronic urticaria is often treated with a second-generation antihistamine at higher than the standard once-daily amount — sometimes considerably higher — under medical supervision, and this works well for many people. Do not increase it yourself, but if standard treatment is not controlling hives, it is worth asking a doctor about, because many people give up assuming nothing more can be done.

Two things it does not do:

It does not treat a cold. Cold symptoms are viral, not histamine-driven. It may slightly dry a runny nose, but it will not shorten the illness or relieve aches and fever.

It does not treat asthma, and is not a substitute for an inhaler.

For blocked nose, antihistamines disappoint. Congestion in allergic rhinitis comes more from inflammation than histamine, and a steroid nasal spray works considerably better for it.

How Allecet fits into this medicine category

GroupExamplesNote
Second-generation antihistaminesCetirizine (Allecet, Seasoneze), loratadine, fexofenadineOnce daily; little drowsiness
First-generation antihistaminesChlorphenamine (Rhineton), promethazineFast and effective; markedly sedating
Steroid nasal spraysFluticasone, mometasoneBest for congestion; work over days
DecongestantsPseudoephedrine, oxymetazolineShort-term only; rebound with overuse
Eye dropsSodium cromoglycate, antihistamine dropsTargeted relief for itchy eyes

See the allergy, cold and flu medicines hub.

What to check before using Allecet

Take one tablet once daily, at any time, with or without food. For a predictable allergy season, starting a week or two beforehand and continuing through works better than reacting to symptoms as they arrive.

Do not take it with another antihistamine, including cold, flu and allergy combination products that contain one already.

Speak to a pharmacist or doctor if:

Avoid alcohol until you know how it affects you.

Follow the pack instructions. This page does not set doses.

Possible cautions and when to ask a pharmacist or doctor

A minority do feel drowsy. If you are one of them, take it in the evening, or ask a pharmacist about loratadine or fexofenadine, which sedate less. Do not drive until you know how you respond.

Dry mouth, headache and tiredness are the other common effects, usually mild.

Do not stop suddenly after long continuous use. A withdrawal itch — intense generalised itching lasting days to weeks after stopping — is recognised in people who have taken cetirizine daily for months or years. It is uncommon, it resolves, and it catches people out badly because it looks like the allergy returning far worse. If you have been on it a long time and want to stop, taper rather than stopping outright, and mention it to a pharmacist.

If it is not helping, something else is going on. Persistent symptoms despite a daily antihistamine may mean congestion is the dominant problem, that the trigger is not allergic, or that additional treatment is needed. Symptoms beyond a few weeks warrant proper assessment.

Reducing exposure helps and lowers how much medicine you need: dust mite covers on bedding, windows shut at high pollen times, showering after being outdoors, drying laundry indoors in pollen season, and keeping pets out of bedrooms.

Seek urgent medical attention for swelling of the face, lips, tongue or throat, difficulty breathing or swallowing, wheezing, faintness with a widespread rash, or a rash that blisters or peels. Hives with any swelling of the mouth or throat is an emergency.

Related medicine guides

Frequently asked questions

What is Allecet 10 mg used for? Hay fever and allergic rhinitis, itchy watery eyes, hives and allergic itching. It contains cetirizine.

Is it the same as Zyrtec or Seasoneze? The active ingredient is the same — cetirizine 10 mg. Brands and manufacturers differ.

Will it make me drowsy? Far less than older antihistamines, though a minority of people notice it. Take it in the evening if so.

Can I take it for a cold? It will not treat a cold, which is viral rather than histamine-driven. It may slightly dry a runny nose.

Will it clear a blocked nose? Only partly. Congestion responds better to a steroid nasal spray used consistently.

Can I just stop after taking it for years? Taper rather than stopping outright. A withdrawal itch is recognised after long continuous use — uncommon, temporary, but easily mistaken for the allergy worsening.