Darunavir and cobicistat (Oral)

Darunavir and cobicistat in combination is used to treat patients who have HIV infection.


The drug, darunavir and cobicistat in combination is used to treat patients who are suffering from Human Immunodeficiency Virus (HIV) infection. HIV is the viral infection that in some people eventually develops into Acquired Immune Deficiency Syndrome (AIDS).

The medication works by preventing the HIV virus from reproducing and therefore helps to slow down the damage that the disease causes to the patient's immune system. Although darunavir and cobicistat in combination cannot cure or prevent HIV and AIDS, it can effectively delay the onset of problems that are often related to HIV or AIDS in some sufferers. It is important to note that the medication will not provide protection against the spread of HIV from one patient to another person.

Darunavir and cobicistat in combination is made in tablet form and is sold under the brand name, Prezcobix in the US. You cannot buy Prezcobix over the counter - it is only available on prescription from your treating specialist or GP.

Conditions treated

  • Human Immunodeficiency Virus (HIV)
  • Acquired Immune Deficiency Syndrome (AIDS)

Type of medicine

  • Tablet
  • Antiviral

Side effects

In addition to the desired effects that it brings, some drugs can cause some unwanted side effects. Not every patient notices undesirable effects when taking darunavir and cobicistat combination, but if you do notice anything unusual, you should speak with your GP, as you may need further medical attention.

If you experience any of the side effects listed below, speak to your doctor immediately:

  • style="font-weight: 400;">white spots, sores, or ulcers in the mouth or on the lips
  • swelling of the lower legs or feet
  • swelling of the hands, face or ankles
  • stupor
  • stomach or abdominal pain or tenderness
  • sore throat
  • skin rash
  • seizures
  • red, irritated eyes
  • red lesions on the skin, sometimes with a purple center
  • rapid weight gain
  • poor appetite
  • Peeling, blistering or loosening of the skin
  • nausea and vomiting
  • muscle twitching
  • muscle or joint pain
  • loss of appetite
  • lethargy
  • jaundice
  • itching
  • irritability
  • hostility
  • headache
  • fever
  • feeling unusually weak or tired
  • dizziness
  • diarrhea
  • depression
  • decreased urine output
  • dark urine
  • cough
  • confusion
  • coma
  • clay colored stools
  • chills
  • agitation

Some patients may experience other effects that are not mentioned here. If you notice anything else that is out of the ordinary for you, check with your treating specialist or GP. Some of the effects resolve themselves as your body gets used to the new drug. However, if you find that the side effects that you are experiencing are particularly irritation or troublesome, have a chat with your doctor for advice on how you can best manage them.


You must take your prescribed dose of darunavir and cobicistat combination exactly as directed by your GP or treating specialist. Do not take more tablets that you are supposed to or take them more frequently. Do not take the medication for a longer period of time than you have been told to. Do not stop taking darunavir and cobicistat unless you are told to by your GP.

When you are given your medication, you will also be given an explanatory information leaflet. Make sure you understand everything in the information leaflet and follow the directions carefully. If you have any questions about your new medication, check with your GP.

It is important that you do not leave any gaps in your treatment regimen. Make sure that you order a refill prescription well ahead so that you do not run out of your medication.

For patients who are also taking didanosine (Videx®), always take this drug either one hour before or two hours after you have taken Prezcobix®.

You should note that the dose of darunavir and cobicistat combination that you have been prescribed will vary between patients. It is important that you follow the directions on the drug packet or those given to you by your GP. The information contained in this guide is based on the average dose rate for this drug. If you have been told otherwise, do not change your dose unless you are directed to do so by your treating physician.

The number of doses that you are told to take each day, the frequency of those doses, and the length of your course of the drug will all depend on a number of factors, including the condition for which you are being treated. Each tablet contains 150 mg of cobicistat and 800 mg of darunavir.

For the treatment of HIV:

  • Adults: take one tablet per day with a meal.
  • Children: your child's doctor will determine the dose and frequency of use of the drug.

If you miss a tablet, try to take as soon as practicably possible. If it is nearly time for your next scheduled tablet, omit the dose that you missed and revert to your usual dosing regimen. If more than 12 hours elapse after your usual dose time, you should omit that tablet and take the next one at its usual time.

Never take twice the dose to try to catch up.


There are some drugs that should never be used together because to do so could cause a dangerous interaction. However, it may be safe and appropriate to take darunavir and cobicistat combination with another prescription drug if this would be the best treatment for you, even though there may be an interaction between the medications. If this is the case, your doctor may change the dose of one or both of your medicines, or recommend other precautions to help mitigate any interaction that might occur.

When you are prescribed darunavir and cobicistat combination, you must tell your GP if you are already taking any of the following drugs. Please note that this list is not necessarily all-inclusive.

  • Zolpidem
  • Warfarin
  • Voriconazole
  • Vorapaxar
  • Vinflunine
  • Vincristine Sulfate Liposome
  • Vincristine
  • Vinblastine
  • Vilazodone
  • Vilanterol
  • Venlafaxine
  • Venetoclax
  • Vemurafenib
  • Vardenafil
  • Trimipramine
  • Triazolam
  • Trazodone
  • Tramadol
  • Trabectedin
  • Toremifene
  • Topotecan
  • Tolvaptan
  • Tipranavir
  • Ticagrelor
  • Tianeptine
  • Thiopental
  • Terfenadine
  • Temsirolimus
  • Telithromycin
  • Telaprevir
  • Tamsulosin
  • Tamoxifen
  • Tadalafil
  • Tacrolimus
  • Suvorexant
  • Sunitinib
  • St John's Wort
  • Sirolimus
  • Simvastatin
  • Simeprevir
  • Silodosin
  • Sildenafil
  • Secobarbital
  • Saxagliptin
  • Saquinavir
  • Salmeterol
  • Ruxolitinib
  • Rosuvastatin
  • Romidepsin
  • Rivaroxaban
  • Ritonavir
  • Riociguat
  • Rifapentine
  • Rifampin
  • Rifabutin
  • Retapamulin
  • Regorafenib
  • Reboxetine
  • Ranolazine
  • Quinidine
  • Quetiapine
  • Protriptyline
  • Propranolol
  • Propafenone
  • Primidone
  • Primidone
  • Prednisolone
  • Pravastatin
  • Ponatinib
  • Pixantrone
  • Pitavastatin
  • Piperaquine
  • Pimozide
  • Pimavanserin
  • Phenytoin
  • Phenobarbital
  • Perphenazine
  • Pentobarbital
  • Pazopanib
  • Paritaprevir
  • Panobinostat
  • Palbociclib
  • Oxycodone
  • Oxcarbazepine
  • Orlistat
  • Opipramol
  • Ondansetron
  • Ombitasvir
  • Olaparib
  • Nortriptyline
  • Norgestrel
  • Norgestimate
  • Norethindrone
  • Norelgestromin
  • Nisoldipine
  • Nimodipine
  • Nilotinib
  • Nifedipine
  • Nevirapine
  • Nelfinavir
  • Naloxegol
  • Naloxegol
  • Nafcillin
  • Morphine Sulfate Liposome
  • Morphine
  • Modafinil
  • Mifepristone
  • Midazolam
  • Mexiletine
  • Methylergonovine
  • Methohexital
  • Mestranol
  • Mephobarbital
  • Melitracen
  • Medroxyprogesterone Acetate
  • Maraviroc
  • Manidipine
  • Macitentan
  • Lurasidone
  • Lumacaftor
  • Lovastatin
  • Lopinavir
  • Lomitapide
  • Lofepramine
  • Lidocaine
  • Levonorgestrel
  • Levomilnacipran
  • Lapatinib
  • Ketoconazole
  • Ivacaftor
  • Ivabradine
  • Itraconazole
  • Isavuconazonium Sulfate
  • Irinotecan Liposome
  • Irinotecan
  • Imipramine
  • Iloperidone
  • Ifosfamide
  • Idelalisib
  • Ibrutinib
  • Haloperidol
  • Grazoprevir
  • Grazoprevir
  • Gestodene
  • Fosphenytoin
  • Fosaprepitant
  • Fosamprenavir
  • Fluvastatin
  • Fluticasone
  • Fluoxetine
  • Flecainide
  • Fentanyl
  • Everolimus
  • Etravirine
  • Etonogestrel
  • Ethynodiol Diacetate
  • Ethinyl Estradiol
  • Eszopiclone
  • Estradiol Valerate
  • Estradiol Cypionate
  • Eslicarbazepine Acetate
  • Erythromycin
  • Erlotinib
  • Ergotamine
  • Ergonovine
  • Eplerenone
  • Elvitegravir
  • Eliglustat
  • Eliglustat
  • Eletriptan
  • Elbasvir
  • Efavirenz
  • Duloxetine
  • Drospirenone
  • Dronedarone
  • Doxorubicin Hydrochloride Liposome
  • Doxorubicin Hydrochloride Liposome
  • Doxorubicin
  • Doxorubicin
  • Doxepin
  • Donepezil
  • Domperidone
  • Domperidone
  • Docetaxel
  • Disopyramide
  • Dihydroergotamine
  • Digoxin
  • Dienogest
  • Didanosine
  • Dibenzepin
  • Diazepam
  • Dextromethorphan
  • Dexamethasone
  • Desogestrel
  • Desipramine
  • Delavirdine
  • Delamanid
  • Dasatinib
  • Dasabuvir
  • Daclatasvir
  • Dabrafenib
  • Dabigatran Etexilate
  • Cyclosporine
  • Cyclophosphamide
  • Crizotinib
  • Conivaptan
  • Conivaptan
  • Colchicine
  • Codeine
  • Cobimetinib
  • Clozapine
  • Clomipramine
  • Clarithromycin
  • Cisapride
  • Cilostazol
  • Ceritinib
  • Cariprazine
  • Carbamazepine
  • Calcifediol
  • Cabozantinib
  • Cabazitaxel
  • Butalbital
  • Butabarbital
  • Budesonide
  • Bromocriptine
  • Bosutinib
  • Bosentan
  • Boceprevir
  • Bedaquiline
  • Avanafil
  • Atorvastatin
  • Atomoxetine
  • Atazanavir
  • Astemizole
  • Aripiprazole
  • Aprobarbital
  • Aprepitant
  • Apixaban
  • Amprenavir
  • Amoxapine
  • Amobarbital
  • Amitriptylinoxide
  • Amitriptyline
  • Amiodarone
  • Amineptine
  • Alprazolam
  • Alfuzosin
  • Afatinib
  • Ado-Trastuzumab Emtansine

Taking darunavir and cobicistat combination with any of the medicines in the bulleted list below could cause a higher risk of some side effects, although taking both medications may be the most appropriate treatment option in your case. If you are told to take both these drugs together, your GP may decide to alter the dose or frequency of use of one or both of the medications.

  • Tenofovir
  • Disoproxil
  • Fumarate
  • Nelfinavir
  • Ketoconazole
  • Indinavir
  • Digoxin
  • Darunavir
  • Cobicistat
  • Clarithromycin
  • Atazanavir

Some drugs should not be taken together with certain types of foods or while using tobacco or alcohol. Be sure to ask your treating physician about the use of your new prescription of darunavir and cobicistat combination with tobacco, food or alcohol.

You must not use darunavir and cobicistat combination if you are already taking any of the following branded medications:

  • Zocor
  • Zepatier
  • Wigraine
  • Versed
  • Uroxatral
  • Tegretol
  • St John's Wort
  • Rimactane
  • Rifadin
  • Revatio
  • Ranexa
  • Propulsid
  • Orap
  • Multaq
  • Mevacor
  • Luminal
  • Latuda
  • Halcion
  • Ergomar
  • Dilantin
  • Colcrys
  • Cafergot


When you decide to begin using a drug, you must weigh the benefits of doing so against the risks. Your doctor will discuss this fully with you before you begin your course of treatment with darunavir and cobicistat combination.

You must remember to inform your GP if you have ever noticed any strange reactions when taking darunavir and cobicistat combination or any other prescription or over the counter drug. You should also mention if you have any allergies to certain food groups, food colorants, animal products or preservatives.

Caution should be exercised when prescribing darunavir and cobicistat combination to elderly patients. This is because older people are more prone to age-related liver disease, which could be aggravated by taking this particular drug.

Pregnancy and breastfeeding

Although there is no definitive evidence to suggest that darunavir and cobicistat combination poses a risk to an unborn baby, if you are pregnant, you should mention this to your doctor. You should also discuss the ramifications of becoming pregnant if you are HIV positive, as this condition will most likely pass to the fetus.

It is unclear whether this drug passes into a mother's milk. However, you should discuss this with your midwife or treating specialist before continuing to breastfeed your infant.

Medical history

There are some existing health conditions that can cause problems when using darunavir and cobicistat combination. Be sure to discuss your medical history fully with your GP before you begin your course of treatment.

Darunavir and cobicistat in combination should be used with caution in patients with the following conditions or with a history of them, as this drug can make these disorders worse:

  • sulfa allergy
  • liver disease, including hepatitis B or C
  • kidney failure
  • hyperglycemia
  • hemophilia
  • Fanconi syndrome (kidney disease)
  • diabetes

Using darunavir and cobicistat combination is not recommended for people who have a severe liver disease.

You will need to see your doctor regularly for progress checks to ensure that the drug is working properly and that no dangerous side effects are evident. As part of this process, your GP may also ask you to have urine and blood tests.

If you begin to notice any of these symptoms, check with your doctor immediately as this could indicate that you are developing a severe liver condition:

  • upper stomach tenderness or pain
  • poor appetite
  • pale stools
  • nausea
  • jaundice
  • feeling very weak or tired
  • dark urine

Some patients experience nasty skin reactions to darunavir and cobicistat in combination. Seek medical advice if you notice:

ulcers, sores or white spots in or around your mouth or lips

Darunavir and cobicistat combination can cause an increase in the blood sugar levels in some people. If you notice changes in your blood or urine sugar test results, you should check with your GP.

Some people taking this medication can develop excess body fat. If you notice that your body shape has changed and that you are carrying more fat around your neck, upper back, stomach or chest, tell your doctor. You may also notice that you have lost fat from around your legs, face and arms.

Darunavir and cobicistat combination can sometimes have the effect of strengthening your immune system. If you notice any changes in your overall health, you should tell your GP. It is possible that your body may begin to fight off conditions, including herpes, pneumonia or tuberculosis. However, you could develop other immune disorders, including Guillain-Barre syndrome, Grave's disease or polymyositis.

You should be aware that darunavir and cobicistat combination will not reduce the risk of you transmitting HIV to other people through contaminated bodily fluids or sexual activity. Always practice safe sex and use condoms, even if you have a regular partner who also has HIV. Never share needles with anyone else.

Do not use any other form of medication, including over the counter products, vitamins or herbal remedies, unless you have discussed their use with your GP first.


You must keep your supply of darunavir and cobicistat tablets in a closed container and at room temperature. Make sure that the tablets are protected from direct sunlight and heat sources, and that they do not get wet. Do not freeze the medicine.

Keep your tablets well away from children and pets. If you think that a pet has eaten any of your darunavir and cobicistat tablets, ask your vet's advice straight away.

If your medication has gone out of date or if the tablets or their packaging appears to be damaged, do not use them. Ask your pharmacist or GP for a fresh supply.

Do not throw unused tablets down the toilet or drain. Wrap them in a sealed bag and place them in your trash can well out of the sight and reach of children and animals.


Darunavir and cobicistat combination is given to patients who are suffering from Human Immunodeficiency Virus (HIV) infection.

The medication can be effective in preventing the HIV virus from reproducing, helping to slow down the damage that the disease causes to the patient's immune system. Darunavir and cobicistat cannot cure or prevent HIV and AIDS, but it can delay the onset of many of the problems that are associated with these conditions. Patients should be aware that the medication will not provide protection against the spread of HIV from one patient to another person.

Before you begin taking darunavir and cobicistat combination tablets, you should discuss your medical history fully with your doctor. There is a wide range of drugs that may cause an interaction when taken with this medicine, and there are also many other health conditions that may become worse because of its effects. You will also need to attend regular check-ups and have blood tests to ensure that the drug is working properly and that your body has not reacted adversely to it.