Fexo refers to fexofenadine, a non-sedating antihistamine sold in South Africa in 120 mg and 180 mg tablets under many “Fexo-” brand names. It is used for hay fever and allergic rhinitis, and for chronic hives. It is the least sedating of the common antihistamines.
What is Fexo?
“Fexo” is a shortening of fexofenadine, and South African products carry a range of names built on it — Fexo-Fast, Fexogen, Fexohet, Fexxtab, Fenofex — alongside others such as Tellerge, Fastway and Pollofex. Check your own pack, which will state fexofenadine and the strength.
| Strength | Typical use |
|---|---|
| Fexofenadine 120 mg | Allergic rhinitis and hay fever |
| Fexofenadine 180 mg | Chronic hives (urticaria) |
Schedules vary between products, from S1 to S3, so availability differs by brand.
Fexofenadine is a third-generation antihistamine. It blocks histamine H1 receptors, reducing the sneezing, itching, runny nose and watery eyes that histamine produces during an allergic reaction.
Its defining feature is how little it enters the brain. Fexofenadine is the active breakdown product of an older antihistamine, terfenadine, and it is actively pumped out of the brain by a transporter called P-glycoprotein. The result is that fexofenadine is the least sedating of the commonly used antihistamines — generally less so than cetirizine, which causes drowsiness in a meaningful minority, and than loratadine.
That makes it the usual choice where alertness genuinely matters — for drivers, pilots, people operating machinery, and students.
The strength difference reflects the condition, not severity. 120 mg is standard for allergic rhinitis; 180 mg is used for chronic hives, which typically needs a higher dose.
What is Fexo commonly used for?
- Seasonal allergic rhinitis (hay fever) — sneezing, runny nose, itchy nose and throat, watery itchy eyes.
- Perennial allergic rhinitis, from year-round triggers such as dust mites, pets or mould.
- Chronic idiopathic urticaria — persistent hives without an identified cause, usually at the higher strength.
- Itchy allergic skin reactions.
- Allergic conjunctivitis.
- Allergy symptoms where drowsiness must be avoided.
Antihistamines work better taken before or early in an exposure than once symptoms are established. For seasonal allergy, starting before the season and taking it regularly generally works better than reaching for it after a bad day.
What it does not do:
- It does not clear a blocked nose well. Congestion comes largely from leukotrienes rather than histamine, which is why a stuffy nose often persists.
- It does not treat colds or flu, which are viral.
- It does not treat asthma.
For persistent allergic rhinitis, a steroid nasal spray is the most effective treatment — better than any antihistamine tablet, and particularly better for congestion. Tablets are often used alongside a spray.
For chronic hives, guidelines support increasing the antihistamine dose above standard under medical supervision — sometimes substantially — before moving to other treatments. That is a decision for a doctor, not something to do yourself.
How Fexo fits into this medicine category
| Group | Examples | Notes |
|---|---|---|
| Non-sedating antihistamines | Fexofenadine (Fexo), loratadine, cetirizine | Allergy without significant sedation |
| Sedating antihistamines | Chlorphenamine, promethazine | Allergy and itch; marked drowsiness |
| Steroid nasal sprays | Fluticasone, budesonide | Most effective for persistent allergic rhinitis |
| Leukotriene antagonists | Montelukast (Glemolev) | Congestion, and allergy with asthma |
| Decongestants | Pseudoephedrine (Decofed) | Blocked nose; short-term only |
| Mast cell stabilisers | Sodium cromoglicate | Preventive, eye and nasal |
Among the non-sedating options, fexofenadine sedates least, cetirizine tends to work fastest, and individuals genuinely respond differently — if one does not suit you, another may. See the allergy, cold, flu and respiratory medicines hub.
What to check before using Fexo
Do not take it with fruit juice. This is the practical point most specific to fexofenadine: apple, orange and grapefruit juice reduce its absorption substantially — by around a third or more — by blocking the transporter that carries it into the bloodstream. Take it with water, and leave a few hours between the tablet and fruit juice.
Separate it from antacids containing aluminium or magnesium by at least two hours, as they also reduce absorption.
Do not take more than one antihistamine at a time without advice, including combination cold and flu products.
Speak to a pharmacist or doctor first if you:
- Have kidney disease, which may mean a lower dose.
- Have heart disease or a rhythm disorder.
- Are elderly.
- Are pregnant or breastfeeding.
- Are giving it to a child, where age and weight determine suitability and paediatric strengths exist.
- Are due to have allergy skin testing. Antihistamines suppress the reaction and must usually be stopped several days beforehand — mention it in advance, or the test may need repeating.
Possible cautions and when to ask a pharmacist or doctor
Fexofenadine is very well tolerated. Common effects are headache, drowsiness (uncommon), dizziness and nausea.
Seek medical attention urgently if you develop:
- Swelling of the face, lips, tongue or throat, or difficulty breathing or swallowing — signs of a serious allergic reaction. Call emergency services.
- A widespread rash with feeling unwell, or blistering or peeling skin.
- A fast or irregular heartbeat, or fainting.
- Yellowing of the eyes or skin.
See a doctor rather than continuing self-treatment if:
- Symptoms persist despite regular treatment, or you need an antihistamine every day for months.
- Hives are persistent, recurrent, or last more than six weeks. Chronic urticaria needs assessment, and higher doses under supervision are often effective.
- Hives come with swelling of the lips, tongue or throat, or breathing difficulty — this is an emergency.
- You have wheezing, chest tightness or breathlessness, as asthma commonly accompanies allergic rhinitis.
- Symptoms follow a food, medicine or insect sting. An antihistamine tablet is not adequate treatment for anaphylaxis.
- You have facial pain, thick discoloured discharge or fever, suggesting sinus infection.
- One-sided nasal blockage or nosebleeds, which need examination.
If you have been prescribed an adrenaline auto-injector, carry it. An antihistamine does not replace it.
Related medicine guides
- Browse Allergy, Cold, Flu & Respiratory Medicines guides
- Read: Austell Cetirizine used for
- Read: Rhineton used for
Frequently asked questions
What is Fexo used for? Hay fever and allergic rhinitis — sneezing, runny nose, itchy watery eyes — and chronic hives. It contains fexofenadine.
What is Fexo 120 used for? The standard strength for allergic rhinitis and hay fever, taken once daily.
What is Fexo 180 mg used for? Chronic hives (urticaria), which typically needs the higher strength.
Does it make you drowsy? Rarely. Fexofenadine is the least sedating of the common antihistamines, which is why it suits drivers and anyone needing full alertness.
Why should I avoid fruit juice with it? Apple, orange and grapefruit juice reduce absorption substantially by blocking the transporter that carries it into the blood. Take it with water.
Is it better than cetirizine or loratadine? It sedates least; cetirizine tends to act fastest. People respond differently, so if one does not suit you, another may.
Will it clear a blocked nose? Not well. Congestion comes largely from leukotrienes rather than histamine — a steroid nasal spray is more effective.
Can I take a higher dose for hives? Only under medical supervision. Guidelines do support increasing the dose for chronic urticaria, but that is a doctor’s decision.