Allegra (Fexofenadine)

It is quite common to experience cold-like symptoms at certain times of year. Sneezing, a blocked nose, watery eyes and a runny nose are some of the most common ones. If you or your children have these symptoms, you may wonder whether they are linked to the weather.

In many cases, though, they are caused by what is commonly known as hay fever. This is a seasonal allergy. Of the different types of allergy, seasonal allergic rhinitis is one of the most common. It happens when spores and pollen from plants, flowers and trees are in the air we breathe.

In some people, these particles, known as allergens, trigger the immune system to release histamine and other chemicals into the bloodstream. Histamine is what causes the symptoms mentioned above.

To counter the effects of this substance in the body, antihistamine medicines can be used. Allegra (fexofenadine) is a well-known medicine of this type. It helps reduce the symptoms mentioned above in children and adults. Allegra is not only used for allergies, though. It is also used in the treatment of urticaria and other conditions. Allegra is available without a prescription and can also be bought as a generic medicine.

In this article, we will look in detail at Allegra, including what it is used for, the recommended dose and possible side effects. This information can help you decide whether this medicine is right for you and, if it is, how to use it properly.

What Is Allegra (Fexofenadine)?

Common questions people ask are, "What is this medicine?" and "What is Allegra usually used for?" Allegra is a non-drowsy (second-generation) antihistamine medicine that contains the active substance fexofenadine (C₃₂H₃₉NO₄). This chemical compound has a molar mass of 501.667 g/mol and belongs to the group of so-called H₁ blockers or H₁ antagonists. Allegra is effective in the treatment of seasonal allergies, urticaria and other immune system reactions.

Another common question is, "How long does Allegra normally take to work?" In general, the medicine starts to work within about 30 minutes. Its effect usually peaks between 1 hour and 2 hours after taking a dose. What does Allegra do while it is working? Put simply, it blocks the effects of histamine in the body. That means it helps relieve symptoms, but it does not cure the underlying cause.

Allegra can be used by both adults and children and is sold as a medicine available without a prescription. This means you can buy it without a prescription from a doctor. However, children's Allegra may be available only on prescription.

When you buy this medicine without a prescription, make sure you read and understand the instructions in the pack. Do not take it unless you are fully sure what the right dose is for you. If you are unsure, ask a pharmacist.

Allegra is sold as tablets, including standard tablets and orally disintegrating tablets. More details are given in the next subsection. There is also an oral suspension, which is the paediatric dosage form. In most cases, this medicine is taken twice a day. However, there is also a once-daily dosage form. It is not recommended to keep using it for more than 5 consecutive days.

Another question people often ask is, "What is the best antihistamine?" or "Is Allegra the best antihistamine?" Most antihistamines on the market are effective and work against the effects of histamine. However, when avoiding drowsiness matters, Allegra may be a better option.

Dosage Forms

As mentioned above, Allegra comes in 3 different dosage forms. They can all be bought in most pharmacies. Below is a more detailed description of each of these available forms.

Tablets

Allegra is available as regular tablets in 2 different strengths of the active substance. They are sold as non-prescription tablets under the names "12 Hour Allegra" and "24 Hour Allegra". In both cases, the active substance is fexofenadine hydrochloride (HCl).

You may have noticed that the word "hydrochloride" has been added to the name of the active substance. Here is a brief explanation. Many medicines are originally made as either a weak acid or a base. However, in many cases the human body cannot absorb the medicine effectively in either of these forms. Poor absorption would make the medicine much less useful because it would not have the intended effect.

To improve absorption, a medicine in an acid or base form can be converted into a salt form through chemical processes. A salt form can also improve how well the medicine dissolves. Dissolution is the process by which the medicine is released from the dosage form, such as a tablet, into the body.

For this reason, pure fexofenadine is chemically converted into fexofenadine HCl to improve its water solubility and bioavailability. This helps the antihistamine to be absorbed in the gastrointestinal tract and distributed quickly through the bloodstream.

As you might expect, 12 Hour Allegra contains less fexofenadine HCl than 24 Hour Allegra. The former contains 60 mg per tablet, while the latter contains 180 mg. Each tablet also contains other inactive ingredients. You can read the full list of ingredients for each tablet on the pack. 12 Hour Allegra is sold in packs of 24 tablets, while 24 Hour Allegra comes in packs of 20 tablets.

The same strength of 180 mg of fexofenadine HCl is available as "24 Hour Allegra Gelcaps". This dosage form is sold in packs of 24 gelcaps. The inactive ingredients differ from those in the solid tablets, so for the full ingredient list for this form, check the pack or the leaflet inside.

Knowing the ingredients in a particular dosage form is important for several reasons. A doctor can decide whether the medicine is suitable for you and whether any of its ingredients could interact with other medicines you are taking. It can also help assess the risk of allergic reactions or other complications.

Oral suspension

Children's Allegra is sold as an oral suspension. As mentioned, this dosage form is not sold without a prescription. In this form, the active ingredient is the same, fexofenadine HCl, but at a lower concentration. This dosage form contains 30 mg per 5 ml. As well as the active ingredient, the suspension contains several inactive ingredients. As in the previous cases, you should read the leaflet inside the pack for the full list of ingredients.

Oral disintegrating tablets

There is also another dosage form for both children and adults that is easier to take and dissolve. These are orally disintegrating tablets, which melt in the mouth. They are recommended for children who cannot swallow solid tablets. Each orally disintegrating tablet contains 30 mg of fexofenadine HCl. This dosage form can be bought in packs of 12 orally disintegrating tablets.

Indications

For your safety, before taking Allegra, make sure you understand how to use it. This is especially important if you buy it without a prescription, which may be possible in pharmacies. If a doctor prescribes it for you, you must take Allegra as directed.

If you have kidney disease, a doctor should decide whether taking fexofenadine is suitable in your case. It is also a good idea to tell them about any other conditions you have, such as diabetes. To help make sure the medicine will not interact with anything else, tell your doctor about all other medicines you are taking.

If you are giving the suspension to your child, shake the bottle well first. Measure the dose in millilitres using a proper measuring device, such as a measuring spoon. Do not use a teaspoon or any other device that does not show whether you have measured the correct dose. A smaller dose may not work properly, while a larger dose increases the risk of overdose.

It is best to take all dosage forms without food. However, the regular tablets and the suspension can be taken with food if you prefer. The orally disintegrating tablets must always be taken without food and on an empty stomach.

Generally, you do not need any liquids. However, if needed, you can drink a glass of water. Do not use natural or artificial juices with this dosage form, as they may interfere with absorption of the active ingredient.

Dosage Considerations

If a doctor prescribes Allegra, they will decide the best dose for you based on several factors. Your age, clinical condition, body weight and response to fexofenadine will all be taken into account. The doctor will also recommend the most suitable dosage form for you. However, if you choose to buy Allegra without a prescription, follow the instructions on the pack.

For the regular 12 Hour Allegra tablets, the doses should be taken as indicated below:

• Children +12 y.o. and adults must take 1 tablet every 12 hours (2 tablets a day);
• Children -12 y.o. must not use this medication;
• Adults +65 y.o. and patients with kidney problems must consult a doctor to ensure that this medication is safe in their particular cases.

For the regular 24 Hour Allegra tablets, the doses should be taken as indicated below:

• Children +12 y.o. and adults must take 1 tablet every 24 hours (1 tablet a day);
• Children -12 y.o. must not use this medication;
• Adults +65 y.o. and patients with kidney problems must consult a doctor to ensure that this medication is safe in their particular cases.

The last directions also apply to the 24 Hour Allegra Gelcaps.

For the oral suspension, the doses should be taken as indicated below:

• Children +12 y.o. and adults must take 10 ml every 12 hours (20 ml a day);
• Children between 2 and 12 years of age must take 5 ml every 12 hours (10 ml a day);
• Children -2 y.o., adults +65 y.o., and patients with kidney problems must consult a doctor to ensure that this medication is safe in their particular cases.

For the orally disintegrating tablets, the doses should be taken as indicated below:

• Children +12 y.o. and adults must take 2 tablets every 12 hours (4 tablets a day);
• Children between 6 and 12 years of age must take 1 tablet every 12 hours (2 tablets a day);
• Children -6 y.o., adults +65 y.o., and patients with kidney problems must consult a doctor to ensure that this medication is safe in their particular cases.

The orally disintegrating tablets must be taken on an empty stomach.

In all cases, do not exceed or reduce the indicated dose, and do not continue treatment for longer than directed. Doing so will not give better or faster results and could be harmful to your health. Taking a higher dose increases the risk of side effects. If your condition does not improve after treatment, or if it gets worse, see a doctor straight away.

Before taking this medicine

Allegra is suitable for most people in most cases. However, to reduce the risk of side effects or a severe allergic reaction, do not take it if you are allergic to fexofenadine. You should also consult a doctor in the following situations.

Ask a doctor before use

If you have kidney disease, or have had it in the past, you must consult a doctor before taking Allegra. If you have diabetes, ask whether this medicine is suitable for you. Orally disintegrating tablets and oral suspension contain aspartame, which may not be suitable for people with diabetes. Also, tell the doctor about all other medicines you are taking and whether you are due to have surgery soon.

If pregnant or breast-feeding

Tell your doctor if you are pregnant or planning to become pregnant soon. There may be risks to the unborn baby if Allegra is taken during pregnancy. The doctor will therefore weigh up whether the benefits of using this medicine outweigh the risks. A doctor should also decide whether Allegra is suitable for you if you are breast-feeding. Fexofenadine can pass to the baby through breast milk.

What happens if I miss a dose

If you miss a dose, take it as soon as you remember. However, if your next dose is due soon, skip the missed dose. In most cases, sticking to an exact schedule is not necessary. Never take a double dose to make up for a missed one, as this could lead to an overdose.

What happens if I overdose

If you take too much, get medical help. See a doctor if you have a dry mouth or feel dizzy or drowsy. Get emergency medical help if you have trouble breathing or feel faint. Call emergency services or a poison control centre.

How should I take Allegra?

As mentioned above, you must follow your doctor's instructions for taking Allegra. Otherwise, follow the directions on the pack. Do not take any antacid within 15 minutes before or after taking any of the dosage forms. These medicines can interfere with absorption of the active ingredient. Likewise, do not drink natural or artificial juice with Allegra.

The regular tablets should be taken with a glass of water. Do not take them with juice, as this will reduce the tablet's effectiveness. Swallow the tablet whole without chewing or biting it. For the liquid dosage form, shake the bottle before taking the dose.

The orally disintegrating tablets need a little more care. Follow these directions:

• Do not remove the tablet from its blister until you are ready to take the dose;
• When you are ready to take it, remove the tablet carefully to avoid damaging it. Make sure your hands are dry when you do this;
• Place the tablet on your tongue. It will start dissolving in your saliva, without the need for water;
• Do not chew, bite or swallow the tablet whole. Let it dissolve on its own;
• Swallow as the tablet dissolves. If needed, you can drink some water. Do not drink any other type of liquid.

Ideally, you should take this dosage form at least 1 hour before a meal. Alternatively, you can take it 2 hours after eating.

Side Effects

Like any medicine, Allegra can cause unwanted effects. Some side effects are mild and go away on their own. Others may need urgent medical attention. A doctor prescribing this medicine in British practice will always weigh up the benefits against the risks. In most cases, however, you will not have any side effects.

Side effects requiring immediate medical attention

You may be experiencing some mild Allegra side effects if you:

• Start coughing or have flu-like symptoms;
• Have a fever, headache and/or chills;
• Have diarrhoea, nausea or any other stomach problem;
• Feel drowsy or tired;
• Have menstrual cramps or back pain;
• Have muscle pain.

Other unwanted effects may also occur, even if they are not listed above. In most cases, these effects go away quickly and do not need medical attention. However, if these side effects do not go away after a few days, you should see a doctor. Likewise, if any of the above symptoms get worse, stop taking Allegra and seek medical advice.

Side effects not requiring immediate medical attention

You should seek emergency medical attention if you notice symptoms of an allergic reaction to Allegra. Although a serious allergic reaction (anaphylaxis) to fexofenadine is very uncommon, it can be fatal if it happens. Therefore, go to A&E straight away if:

• You develop a rash, hives or itching;
• You cannot breathe normally;
• Your face, lips and/or tongue start to swell;
• You feel severely dizzy.

Call emergency services if you cannot get to hospital straight away by yourself.

What other drugs will affect Allegra?

The interaction between antacids and Allegra was mentioned earlier.  To allow a full assessment, tell the doctor about any other medicines you may be taking. These include prescription medicines, non-prescription medicines, food supplements and herbal products. You should also tell them about any recreational drugs you use regularly or occasionally.

Medicines that can cause sleepiness are especially important when checking for possible interactions. Tell the doctor if you take sleeping pills, painkillers, sedatives or similar medicines. Also mention whether you have a mental health condition and take medicine for it. Likewise, avoid drinks with a high alcohol content while you are being treated with Allegra.

Storage

Allegra should always be kept out of the reach of children. Store this medicine in a dry place at room temperature between 20°C and 25°C (68°F and 77°F). Discard the medicine if the blisters, carton or bottle are open. Check the expiry date as well, and dispose of any medicines that have already expired.