Darunavir

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.

Darunavir, (Prezista®) 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 darunavir
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 including sulphonamides e.g. co-trimoxazole (Septrin®);
* If you have ever had any liver disease;
* If you are pregnant or planning a pregnancy;
* If you are diabetic;
* If you are a haemophiliac;

Taking your darunavir

* Darunavir is available as an orange film-coated oval-shaped tablet (debossed with 300mg on
one side and TMC114 on the other) containing 300mg of darunavir;
* The recommended dose of darunavir is 600mg (2 tablets) twice daily plus 100mg (1 capsule)
ritonavir twice daily taken with food. It is can also be taken as 900mg (3 tablets) once a day
plus 100mg (1 capsule) ritonavir once daily with food (this dose is unlicensed);
* Darunavir must be taken with ritonavir which boosts the amount of darunavir in the body, so
making it more effective;
* You should always take darunavir with food. This helps the drug to be absorbed from the
stomach. Swallow the tablet whole. Do not crush, break, or chew it;
* The doses should be divided equally throughout the day: try to take the doses as close as
possible to twelve hours apart (or 24 hours apart if taken once daily), and at the same times
each day;
* Darunavir, 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 if it is within 6 hours of the time you usually
take it, if it is later than 6 hours after the time you usually take your dose, the missed dose
should not be taken and you should resume your usual dosing schedule;

Do not run out of darunavir. 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 darunavir/ritonavir
Darunavir and ritonavir are 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 darunavir boosted with ritonavir and should NOT be taken are rifampicin, phenytoin, carbamazepine, phenobarbital, simvastatin, ergotamine, terfenadine (Triludan®) and St. Johns Wort (Hypericum perforatum).

Other examples of drugs that are metabolised in the same way as darunavir boosted with ritonavir include rifabutin, warfarin, methadone, drugs for erectile dysfunction (e.g. Viagra®), some drugs that treat depression, NNRTIs, fluticasone, tacrolimus, ciclosporin, other protease inhibitors, medicines for heart rhythm problems (e.g. digoxin, amiodarone), medicines to treat a
fungus infection (such as itraconazole, ketoconazole) and certain blood pressure medicines.

Your doctor may alter your doses if you are taking one of these drugs. Darunavir can stop hormonal contraceptives from working effectively, so you must use an alternative form of contraception, e.g. barrier methods.

Side effects
Darunavir, like all other medicines, has some side effects. The most common ones (incidence of more than 1 in 100 patients) are:

* Nausea and vomiting;
* Abdominal pain, constipation, flatulence, abdominal distension, dyspepsia, Diarrhoea;
* Asthenia (lack of energy, strength) and fatigue (tiredness);
* Insomnia;
* Headache, dizziness

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, raised triglycerides, 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 darunavir, tell your doctor who will advise you what to do. If you decide to stop taking darunavir 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 darunavir
Darunavir should be stored at room temperature.