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The eMC  

Last Updated 20 Jul 2015

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Isotrexin gel

Isotrexin (Eye-soh-trek-sin) is a medicine which is used in treating acne. Isotrexin contains erythromycin/isotretinoin. It is supplied by GlaxoSmithKline UK.

The information in this Medicine Guide for Isotrexin varies according to the condition being treated and the particular preparation used.

Isotrexin gel

Information specific to Isotrexin gel when used in treating acne

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Your medicine

Isotrexin contains two medicineserythromycin and isotretinoin. Erythromycin is an antibiotic and works by stopping the growth of bacteria associated with acne. Isotretinoin stops the formation of blackheads or whiteheads. Both medicines also work to reduce the inflammation that occurs with acne.

Isotrexin can cause your skin to become more sensitive to all forms of UV light. While you are using Isotrexin, it is important to protect the skin from the effects of UV light. You should try reducing the time you are exposed to direct sunlight. Areas which have been treated with Isotrexin should not be exposed to the sun and should be covered with appropriate clothing or a high protection sun screen. You should also avoid using tanning beds or lamps while you are using Isotrexin.

You should take care not to apply too much of Isotrexin as the skin may become red, irritated or start to peel. Using more than the amount prescribed does not lead to a better or faster treatment of acne.

You should be careful not to get Isotrexin in or around your eyes, mouth, nose, lips or mucous membranes. Do not apply Isotrexin onto irritated areas of skin or onto skin with eczema. You must be careful when applying Isotrexin to your neck or other areas of sensitive skin. For more information about using Isotrexin on areas of sensitive skin, talk to your prescriber. Wash your hands after using Isotrexin.

Other information about Isotrexin:

  • you may need to use Isotrexin for several weeks before you can expect to see any benefits from using this medicine. For more information about when you would expect to see these benefits and how long your treatment with Isotrexin will last for, talk to your prescriber
  • if you are using other skin preparations to treat acne while you are using Isotrexin, you may need to apply the other skin preparations at a different time of day to when you would usually use Isotrexin

Do not share your medicine with other people. It may not be suitable for them and may harm them.

The pharmacy label on your medicine tells you how much medicine you should use. It also tells you how often you should use your medicine. This is the dose that you and your prescriber have agreed you should use. You should not change the dose of your medicine unless you are told to do so by your prescriber.

If you feel that the medicine is making you unwell or you do not think it is working, then talk to your prescriber.

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When to take your medicine

Some medicines work best if they are taken at a specific time of day. Getting the most from your medicine can also be affected by the times at which you take other medicines.

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How to take your medicine

Some medicines have specific instructions about how to take them. This is because they work better when taken correctly. These instructions can include getting the right dose and special instructions for preparing the medicine.

In the case of Isotrexin:

  • detailed advice on how to use Isotrexin can be found in the Patient Information Leaflet that comes with this medicine
  • before you apply Isotrexin gently clean the affected area
  • apply a thin layer to the affected area of skin
  • wash your hands after you have applied your medicine
  • when applying Isotrexin take care not to accidentally get Isotrexin in your eyes or other parts of your body that are not being treated
  • if your skin reacts badly to Isotrexin speak to your prescriber

If you are having problems taking this medicine, you should talk to your prescriber or pharmacist. They may be able to give you advice on other ways to take your medicine or other medicines that are easier for you to take.

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Taking too much of your medicine

Taking extra doses of some medicines can be harmful. In some cases even one extra dose can cause you problems. If you take extra doses of your medicine, you must get medical advice immediately. This is because the effects of taking too much medicine are very complex so it is very important that you seek medical advice.

Contact your prescriber, pharmacist, specialist clinic or call 111 for advice.

Make sure you take all of your medicine containers with you if you are advised to go to hospital.

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Stopping your medicine

Suddenly stopping your medicine may cause your original condition to return. This is why you must speak to your prescriber if you are having any problems using your medicine.

If you are not having any problems taking this medicine then do not stop using it, even if you feel better, unless advised to do so by your prescriber.

If you are in any doubt, contact your prescriber, pharmacist, specialist clinic or call 111.

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Looking after your medicine

The instructions on how you should keep your medicine are on the pharmacy label. You should keep your medicine in the original container. This will help to keep your medicine in the best condition and also allow you to check the instructions. Do not take the medicine if the packaging appears to have been tampered with or if the medicine shows any signs of damage. Make sure that the medicine is out of the sight and reach of children.

In the case of Isotrexin:

  • do not store in temperatures above 25°C

You must not take the medicine after the expiry date shown on the packaging. If you have any unused medicine, return it to your pharmacist who will dispose of it safely.

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Whether this medicine is suitable for you

Isotrexin is not suitable for everyone and some people should never use it. Other people should only use it with special care. It is important that the person prescribing this medicine knows your full medical history.

Your prescriber may only prescribe this medicine with special care or may not prescribe it at all if you:

  • are allergic or sensitive to or have had a reaction to any of the ingredients in the medicine
  • are breast-feeding
  • are planning to have a baby
  • are pregnant
  • have had a photoallergic reaction
  • have had or have a family history of skin cancer
  • have had problems tolerating Isotrexin or similar retinoid products in the past
  • have or have had gastrointestinal problems such as ulcerative colitis or pseudomembranous colitis
  • have recently had treatments such as depilation, chemical peels, dermabrasion, chemical hair treatments or laser resurfacing
  • have sensitive skin in the area where you are planning to apply Isotrexin
  • have skin problems such as rosacea, eczema or dermatitis around the mouth
  • have sunburn

Furthermore the prescriber may only prescribe this medicine with special care or may not prescribe it at all for a child under 12 years of age.

As part of the process of assessing suitability to take this medicine a prescriber may also arrange tests:

  • to determine whether or not the medicine is suitable and whether it must be prescribed with extra care

Over time it is possible that Isotrexin can become unsuitable for some people, or they may become unsuitable for it. If at any time it appears that Isotrexin has become unsuitable, it is important that the prescriber is contacted immediately.

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A medicine is only made available to the public if the clinical trials have shown that the benefits of taking the medicine outweigh the risks.

Once a medicine has been licensed, information on the medicine's effects, both intended and unintended, is continuously recorded and updated.

Some side-effects may be serious while others may only be a mild inconvenience.

Everyone's reaction to a medicine is different. It is difficult to predict which side-effects you will have from taking a particular medicine, or whether you will have any side-effects at all. The important thing is to tell your prescriber or pharmacist if you are having problems with your medicine.

Very common: More than 1 in 10 people who use Isotrexin:

  • burning sensation
  • dryness
  • itching
  • pain
  • scaling
  • skin discomfort, redness, irritation or peeling of the skin - seek medical advice if you have skin discomfort, redness, irritation or if your skin starts to peel in the area where you are using Isotrexin. You may have to stop using this medicine for a few days
  • skin rash or rashes

Common: More than 1 in 100 people who use Isotrexin:

  • application site problems such as eczema or certain types of dermatitis - seek medical advice if you develop dermatitis

The frequency of these side-effects is unknown:

  • allergic reactions
  • antibiotic resistance to erythromycin
  • diarrhoea - seek immediate medical advice if you have diarrhoea
  • increased skin sensitivity to sunlight or UV light - you should protect your skin from the effects of UV light by avoiding or reducing the time you are exposed to sunlight or sunlamps during treatment with Isotrexin. If you develop sunburn you must seek medical advice. You may have to stop using Isotrexin for a short period of time
  • irritation of the eyes or mucous membranes if Isotrexin is applied accidentally to these areas
  • oedema of the face
  • overgrowth of micro-organisms that are not affected by Isotrexin
  • photosensitivity skin reaction
  • pseudomembranous colitis - seek immediate medical advice if you have stomach cramps or diarrhoea
  • skin colour changes
  • stomach pain or discomfort
  • urticaria

If you feel unwell or if you have concerns about a side-effect, you will need to seek advice. If you feel very ill, get medical help straight away. Contact your prescriber, pharmacist, nurse or call 111.

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Taking other medicines

If you are taking more than one medicine they may interact with each other. At times your prescriber may decide to use medicines that interact, in other cases this may not be appropriate.

The decision to use medicines that interact depends on your specific circumstances. Your prescriber may decide to use medicines that interact, if it is believed that the benefits of taking the medicines together outweigh the risks. In such cases, it may be necessary to alter your dose or monitor you more closely.

Tell your prescriber the names of all the medicines that you are taking so that they can consider all possible interactions. This includes all the medicines which have been prescribed by your GP, hospital doctor, dentist, nurse, health visitor, midwife or pharmacist. You must also tell your prescriber about medicines which you have bought over the counter without prescriptions.

The following medicines may interact with Isotrexin:

  • benzoyl peroxide
  • clindamycin

The following types of medicine may interact with Isotrexin:

If you are taking Isotrexin and one of the above medicines or types of medicines, make sure your prescriber knows about it.

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Complementary preparations and vitamins

Medicines can interact with complementary preparations and vitamins. In general, there is not much information available about interactions between medicines and complementary preparations or vitamins.

If you are planning to take or are already taking any complementary preparations and vitamins you should ask your prescriber whether there are any known interactions with Isotrexin.

Your prescriber can advise whether it is appropriate for you to take combinations that are known to interact. They can also discuss with you the possible effect that the complementary preparations and vitamins may have on your condition.

If you experience any unusual effects while taking this medicine in combination with complementary preparations and vitamins, you should tell your prescriber.

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Driving and operating machinery

When taking any medicine you should be aware that it might interfere with your ability to drive or operate machinery safely.

Like all medicines Isotrexin can cause side effects. You should see how this medicine affects you and then judge if you are safe to drive or operate machinery. If you are in any doubt, talk to your prescriber.

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Medicines can interact with certain foods. In some cases, this may be harmful and your prescriber may advise you to avoid certain foods.

In the case of Isotrexin:

  • there are no specific foods that you must exclude from your diet when using Isotrexin
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Alcohol can interact with certain medicines.

In the case of Isotrexin:

  • there are no known interactions between alcohol and Isotrexin
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Family planning and pregnancy

Most medicines, in some way, can affect the development of a baby in the womb. The effect on the baby differs between medicines and also depends on the stage of pregnancy that you have reached when you take the medicine.

In the case of Isotrexin:

  • you must not use Isotrexin during pregnancy. If you could become pregnant, you must use effective contraception or abstain from penetrative sex. You must contact your prescriber if you become pregnant, or think you have become pregnant, while using Isotrexin
  • Isotrexin is a medicine which has implications for pregnancy as it may harm a baby. If you are using Isotrexin and are planning to have a baby you must contact your prescriber. You will need to stop using Isotrexin for one cycle before the time you plan to become pregnant. You should discuss with your prescriber when you should stop using this medicine

This medicine is not suitable during pregnancy. It is very important that you seek urgent medical advice if you become pregnant or think you have become pregnant while taking this medicine.

If you are planning to become pregnant, you should discuss your personal circumstances with your doctor so that together you can make a decision about what treatment you may need during your pregnancy.

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Certain medicines can pass into breast milk and may reach your baby through breast-feeding.

In the case of Isotrexin:

  • it is not known whether this medicine passes into breast milk

Women who are using Isotrexin must not breast-feed. If you wish to breast-feed you should discuss with your prescriber whether there are any other medicines you could have. You should not stop this medicine without taking advice from your doctor.

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Ingredients of your medicine

Medicines contain active ingredients. They may also contain other, additional ingredients that help ensure the stability, safety and effectiveness of the medicine. They are also added to improve the medicine's appearance and to make it easier to use. Some may be used to prolong the life of the medicine.

Isotrexin contains:

If you are not able to take any of the ingredients in your medicine, talk to your prescriber or pharmacist to see if they can suggest an alternative medicine. If you have reacted badly to Isotrexin before, do not use Isotrexin. Talk to your prescriber, pharmacist or nurse as soon as possible.

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Isotrexin, Version 8, last updated 20 Jul 2015