Fosamprenavir

Please read this factsheet carefully, along with the patient information leaflet before taking your medicine. If you have any questions or are unsure about anything, ask your doctor or pharmacist.

Fosamprenavir belongs to a class of drugs called protease inhibitors (PIs). PIs are used for the treatment of HIV infection in combination with other anti-HIV drugs. Please speak to your clinic doctor or pharmacist if you would like more information about how these drugs work.

Before taking fosamprenavir
Tell your doctor about:

* All other drugs you are taking, including any that you buy over the counter in a community pharmacy and
any herbal medicines or recreational drugs.
* Previous allergy to any medicines.
* If you have ever had any liver disease.
* If you are pregnant or planning a pregnancy.
* If you are diabetic.
* You are a haemophiliac.

Taking your fosamprenavir

* Fosamprenavir is available as a pink bullet-shaped film-coated tablet containing 700mg of fosamprenavir (this is equivalent to 600mg of amprenavir). It is also available as a liquid containing 50mg per ml.
* The usual dose of fosamprenavir is 700mg (1 tablet) twice daily plus 100mg (1 capsule) ritonavir twice daily. The dose can sometimes be taken once a day (1400mg fosamprenavir and 200mg ritonavir taken as a single dose), although this is not always recommended.
* Fosamprenavir must be taken with ritonavir which boosts the amount of fosamprenavir in the body, so making it more effective.
* The doses should be divided equally throughout the day: try to take the doses as close as possible to twelve hours apart if twice daily, 24-hourly if once daily and at the same times each day.
* Fosamprenavir can be taken with or without food but when taken with ritonavir requires food.
* Fosamprenavir, like all antiretrovirals, works best if there is a constant amount in your bloodstream. It is therefore very important to take the capsules regularly. If you forget to take a dose take it as soon as you remember, but do not double up the next dose.

Do not run out of fosamprenavir. If you are going on holiday and need additional supplies, tell your doctor. When receiving a supply from pharmacy, ensure that you have an adequate supply to last until your next appointment.

Other drugs and fosamprenavir
Fosamprenavir is metabolised (processed in the body) by the liver. Some other drugs are metabolised in the same way. This is why it is important to tell your doctor about all the medicines that you take even if you only take them occasionally, including herbal and recreational drugs.

Examples of some drugs that are metabolised in the same way as fosamprenavir and should NOT be taken are rifampicin, phenytoin, carbamazepine, simvastatin, ergotamine, certain benzodiazepines, terfenadine (Triludan®), amiodarone and St. Johns Wort.

Other examples of drugs that are metabolised in the same way as fosamprenavir include rifabutin, warfarin, methadone, drugs for erectile dysfunction (e.g. Viagra®), NNRTIs, fluticasone and other protease inhibitors. Your doctor may alter your doses if you are taking one of these drugs.

Fosamprenavir can stop hormonal contraceptives from working effectively, so you must use an alternative
form of contraception, e.g. barrier methods.

Side effects
Fosamprenavir, like all other medicines, has some side effects. The most important ones are:

* Nausea and vomiting;
* Diarrhoea;
* Fatigue (tiredness);
* Headache and dizziness;
* Rash;
* Fosamprenavir can rarely cause a severe rash associated with blistering and ulceration. If this occurs
consult a doctor immediately;
* Tingling around the mouth, lips and tongue;
* Skin rash – If you experience a MILD skin rash do not stop taking your Fosamprenavir but contact your doctor and they will advise you what to do. If you experience a SEVERE SKIN RASH or a rash accompanied by other symptoms such as fever, blistering, oral lesions, conjunctivitis, facial swelling, muscle or joint aches or general malaise STOP taking your Fosamprenavir and contact your doctor IMMEDIATELY.

Combination regimens containing protease inhibitors have been associated with redistribution of body fat in some patients. They are also associated with metabolic abnormalities such as raised cholesterol, increased risk of diabetes and heart disease. This collection of side effects are often called ‘lipodystrophy’ and your clinic doctor will monitor you for all of these.

If you experience any of these side effects or any other new symptoms after starting fosamprenavir, tell your doctor who will advise you what to do. If you decide to stop taking fosamprenavir it is important that you tell your doctor so that he or she can discuss other treatment options with you.

Admission to hospital
If you are admitted to hospital please bring all your medicines with you. This is especially important for anti-
HIV drugs, as they have to be taken regularly. Thomas Macaulay Ward operates a self medication
programme. Some people are able to self administer their own medicines to enable them to stick to the
routine they have been used to at home.

Storing your fosamprenavir
Fosamprenavir should be stored at room temperature.