Lorfast contains loratadine 10 mg, a once-daily non-sedating antihistamine. It treats hay fever, allergic rhinitis, itchy watery eyes, hives and allergic itching. It is the least sedating of the commonly used antihistamines, which makes it suited to daytime use.
What is Lorfast?
Lorfast contains loratadine 10 mg, a second-generation antihistamine. It is a Schedule 2 medicine, and the same ingredient is sold as Loratadine, Clarityne, Lorano and Allergex Non-Drowsy.
When the immune system treats something harmless as a threat — pollen, dust mite, mould, animal dander — mast cells release histamine. Histamine binding to H1 receptors produces sneezing, an itchy runny nose, watery eyes, and in the skin, weals and itching. Loratadine occupies those receptors so histamine cannot.
Its defining feature is how little it sedates. First-generation antihistamines such as the chlorphenamine in Allergex cross freely into the brain and cause pronounced drowsiness. Loratadine barely crosses at all, and at standard amounts most people notice no sedation whatsoever — less even than cetirizine, which sedates a minority.
That makes it the usual recommendation for someone who needs allergy control while driving, studying, working or operating machinery.
The trade-off is modest: cetirizine, as in Sensahist, is somewhat more effective for itching and for hives. For nasal allergy symptoms the two perform similarly.
What is Lorfast commonly used for?
- Hay fever (seasonal allergic rhinitis) — sneezing, runny and itchy nose, itchy throat, watery eyes.
- Perennial allergic rhinitis, from dust mite, mould or pet dander.
- Allergic conjunctivitis — itchy, red, watery eyes.
- Chronic urticaria (hives).
- Itching from allergic skin conditions and insect bites.
- Mild allergic reactions.
For seasonal allergy, timing improves results. An antihistamine blocks histamine from binding but does not reverse a reaction already under way. Starting it a week or two before your usual trigger season, and taking it daily through the season rather than only on bad days, gives noticeably better control.
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 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 underperform expectations. Congestion in allergic rhinitis is driven more by inflammation than histamine, and a steroid nasal spray used consistently over one to two weeks works considerably better. Many people with persistent hay fever do best with the spray as the foundation and loratadine on top for sneezing and itching.
How Lorfast fits into this medicine category
| Group | Examples | Note |
|---|---|---|
| Second-generation antihistamines | Loratadine (Lorfast), cetirizine (Sensahist, Zelary), fexofenadine | Once daily; minimal drowsiness |
| First-generation antihistamines | Chlorphenamine (Allergex, Rhineton) | Effective; markedly sedating |
| Steroid nasal sprays | Fluticasone, mometasone | Best for congestion; work over days |
| Decongestants | Pseudoephedrine, oxymetazoline | Short-term only; rebound with overuse |
| Eye drops | Sodium cromoglycate, antihistamine drops | Targeted relief for itchy eyes |
See the allergy, cold and flu medicines hub.
What to check before using Lorfast
Take one tablet once daily, at any time, with or without food.
Do not take it with another antihistamine, including combination cold, flu and allergy products that already contain one.
Speak to a pharmacist or doctor if:
- You have liver disease. Loratadine is processed by the liver, and a reduced amount or alternate-day dosing may be appropriate — this matters more for loratadine than for cetirizine, which is cleared by the kidneys.
- You have kidney disease.
- You are pregnant or breastfeeding.
- The medicine is for a child. Syrups and lower strengths exist — check the right form and amount.
- You take ketoconazole, itraconazole or erythromycin, which raise loratadine levels.
- You are due allergy testing. Antihistamines suppress skin prick test results and usually must be stopped several days beforehand — tell whoever arranges the test.
Avoid alcohol until you know how it affects you, though the interaction is much less pronounced than with sedating antihistamines.
Follow the pack instructions. This page does not set doses.
Possible cautions and when to ask a pharmacist or doctor
Drowsiness is uncommon at standard amounts — that is the point of loratadine. It becomes more likely if you exceed the recommended amount, which is one reason not to take extra when symptoms are bad. If more control is needed, ask rather than doubling up.
Headache, dry mouth and tiredness are the usual complaints, generally mild.
If it is not working, switch rather than escalating. Cetirizine is more effective for itching and hives in many people. Persistent symptoms despite a daily antihistamine can also mean congestion is the dominant problem, or that the trigger is not allergic at all.
Symptoms lasting beyond a few weeks warrant assessment, particularly if you need it year-round.
Reducing exposure helps and lowers how much medicine you need: dust mite covers on mattress and pillows, windows shut at high pollen times, showering and changing after being outdoors, drying laundry indoors during pollen season, and keeping pets out of bedrooms.
Do not use decongestant nasal sprays for more than a few days. They work briefly then cause rebound congestion worse than the original.
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, not an allergy inconvenience.
Related medicine guides
- Browse Allergy, Cold & Flu Medicines guides
- Read: Austell Cetirizine used for
- Read: Rhineton used for
Frequently asked questions
What is Lorfast 10 mg used for? Hay fever and allergic rhinitis, itchy watery eyes, hives and allergic itching. It contains loratadine.
Will it make me drowsy? Usually not. Loratadine is the least sedating of the commonly used antihistamines, which is why it suits daytime use.
How is it different from cetirizine? Both are once-daily and non-sedating. Cetirizine is somewhat more effective for itching and hives; loratadine sedates even less.
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 over one to two weeks.
Can I take two if one is not enough? No — exceeding the recommended amount makes drowsiness more likely without reliably improving control. Ask a pharmacist about switching instead.