Symtuza is a complete single-tablet antiretroviral regimen that combines four medicines in one tablet:

• Darunavir: a protease inhibitor that blocks HIV from producing new virus particles
• Cobicistat: a pharmacokinetic booster that keeps darunavir levels high enough for once-daily dosing
• Emtricitabine: a nucleoside reverse transcriptase inhibitor (NRTI) that blocks HIV replication
• Tenofovir alafenamide (TAF): a newer form of tenofovir with less impact on kidneys and bones than older formulations
  
  

Symtuza is used in adults living with HIV who are either treatment-naive or who are switching from a stable regimen (virologically suppressed, no known resistance to the components).

Take one tablet once daily with food. Food is important for absorption of both darunavir and cobicistat.

Take at the same time each day. Do not stop without speaking to your HIV doctor.

If you remember within 12 hours of your usual dose time, take it with food immediately. If more than 12 hours have passed, skip that dose and take the next one as usual. Never take two doses at once.

Contact your HIV specialist or a poison control centre.

• Store below 30°C in the original container
• Keep out of reach of children

Common side effects:

• Diarrhoea
• Nausea
• Headache
• Rash: darunavir contains a sulfonamide component. Tell your doctor about any sulfa drug allergies

Important monitoring points:

• Kidney function: cobicistat raises creatinine slightly (due to its effect on kidney transporters), but TAF has less true kidney impact than older tenofovir formulations. Monitoring is still required
• Liver enzymes: monitored during treatment
• Cholesterol and blood sugar: protease inhibitor class effects
• Hepatitis B flare: do not stop Symtuza without medical advice if you have hepatitis B

Regular blood tests including viral load, kidney, liver, and lipids are checked routinely.

Cobicistat is a strong CYP3A4 inhibitor with the same broad interaction profile as ritonavir:

• Statins: simvastatin and lovastatin are contraindicated
• Rifampicin, St John's Wort: dramatically reduce darunavir levels. Avoid
• Antiepileptics (carbamazepine, phenytoin): reduce darunavir levels
  

Always check for interactions before starting any new medicine. Your HIV pharmacist should review your full medicine list.

What makes Symtuza different from other single-tablet regimens?

Symtuza contains a darunavir-based regimen in a single tablet, which is unusual. Most other single-tablet regimens are based on integrase inhibitors. Darunavir has a high genetic barrier to resistance, making Symtuza particularly suitable for people who have had prior treatment difficulties or who are starting HIV treatment for the first time and want a very robust resistance profile. The inclusion of TAF also makes it kidney- and bone-friendly.

Does Symtuza treat hepatitis B?

Emtricitabine and TAF both have activity against hepatitis B virus. If you have HIV and hepatitis B co-infection, Symtuza can treat both. However, do not stop Symtuza without medical supervision, as stopping can cause a serious hepatitis B flare.

Ace provides accurate and independent information medically reviewed on prescription medications. This material is provided for educational purposes only and is not intended for medical advice, diagnosis or treatment.