Allergy, Cold, Flu & Respiratory Medic Guides

What Allergy, Cold, Flu & Respiratory Medicines covers

This section covers antihistamines, decongestants, cough preparations, combination cold and flu remedies, and medicines for asthma and other respiratory conditions.

More medicine is bought without advice here than anywhere else on the site, and the products are unusually easy to misuse — not because any one of them is especially dangerous, but because they are so often combined. A cold and flu sachet, a separate painkiller and a cough syrup taken together can easily deliver two doses of paracetamol and two sedating ingredients without the person realising.

The groups are: antihistamines, split into older sedating ones such as Allergex and newer non-drowsy ones such as cetirizine and loratadine; decongestants, which relieve blocked noses and raise blood pressure; cough preparations, either suppressants or expectorants; combination cold and flu products, which bundle several of the above; and respiratory medicines including inhalers.

The most useful thing to establish about any product here is which ingredients it actually contains.

Browse individual used-for guides

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B

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D

F

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H

Histacon used for

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Oxylin used for

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Venteze used for

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Xyzal used for

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Yellow used for

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Most searched questions in this topic

How the guides in this section differ

Sedating or non-sedating antihistamine. Older antihistamines such as chlorpheniramine cause real drowsiness, which is sometimes wanted at night and is a problem before driving. Cetirizine, loratadine and similar are far less sedating and suit daytime use. Cetirizine sits in between for some people.

Single ingredient or combination. A combination cold and flu product typically contains a painkiller, a decongestant and often an antihistamine or cough suppressant. Convenient, but it is where accidental double-dosing starts.

Suppressant or expectorant. A cough suppressant reduces the urge to cough; an expectorant aims to loosen mucus. They are opposites, and a few products contain both.

Allergy or infection. Antihistamines address allergy. They do not treat a cold, and no product in this section shortens one. The realistic aim is symptom relief while it passes.

Working out whether you are dealing with allergy or infection saves buying the wrong thing:

	Allergy	Cold or flu
Onset	Sudden, on exposure	Builds over a day or two
Itching	Common, especially eyes and nose	Unusual
Fever	No	Often, particularly with flu
Aches	No	Common
Duration	As long as the exposure lasts	About a week
Time of year	Often seasonal or situational	Any time
What helps	Antihistamine; avoiding the trigger	Rest, fluids, symptom relief

Symptom	Group that helps	Note
Sneezing, itchy eyes, runny nose from allergy	Antihistamine	Non-sedating for daytime
Blocked nose	Decongestant	Caution with high blood pressure; limit nasal sprays to a few days
Dry, irritating cough	Suppressant	Not for a productive cough
Chesty, productive cough	Expectorant	Fluids help as much as the syrup
Aches and fever	Paracetamol or an anti-inflammatory	Check it is not already in a combination product

Safety, accuracy and next-step checks

These guides are informational and do not diagnose.

Points worth carrying:

Check for paracetamol before adding a painkiller. It is in most combination cold and flu products. Doubling up is the most common serious accidental overdose, and liver damage can develop without early symptoms.
Decongestants raise blood pressure and can affect the heart. If you have hypertension, heart disease, an overactive thyroid, glaucoma or prostate problems, ask a pharmacist first.
Decongestant nasal sprays should not be used beyond a few days. Longer use causes rebound congestion that is worse than the original.
Sedating antihistamines and driving. They impair reactions, and the effect can persist into the next morning.
Cough and cold products for children. Many are unsuitable under six, and dosing differs by age and weight. Ask a pharmacist rather than estimating.
Do not use antibiotics for a cold. They have no effect on viruses.
Asthma inhalers are not interchangeable. A reliever and a preventer do different jobs, and using a reliever more often than usual is a sign to be reviewed rather than to continue.

See a doctor for breathlessness, chest pain, a fever that persists beyond a few days or rises again after improving, coughing up blood, or symptoms lasting beyond about ten days. For a child, a lower threshold is appropriate.

Frequently asked questions

Which antihistamine will not make me drowsy? Loratadine and similar newer antihistamines are the least sedating. Cetirizine causes drowsiness in some people. Older ones such as chlorpheniramine reliably do.

Can I take a cold and flu remedy with paracetamol? Usually not, because the remedy almost certainly already contains it. Read the ingredients first and ask your pharmacist.

Will anything shorten my cold? No. The products here relieve symptoms while your immune system deals with it. Rest and fluids remain the substance of the treatment.

Why must I stop a decongestant nasal spray after a few days? Extended use causes rebound congestion, where the nose becomes more blocked than before and stays that way until the spray is stopped.

Is it allergy or a cold? Allergy tends to be itchy, seasonal or triggered by a specific exposure, without fever. A cold usually brings aches and sometimes fever and resolves within a week or so. A pharmacist can help you tell them apart.

Allergy, Cold, Flu & Respiratory Medicines Used-For Guides