What is it prescribed for?
IDVYNSO is prescribed for adults with HIV-1 infection who are already virologically suppressed on a stable antiretroviral regimen. This means their HIV viral load is already controlled at very low levels before switching to IDVYNSO. HIV is a lifelong viral infection that attacks the immune system and requires continuous treatment to prevent progression to AIDS and other complications. Many patients remain on treatment for decades, so newer therapies that reduce pill burden and simplify care are important. IDVYNSO offers a complete two-drug treatment option that may help certain patients maintain viral suppression with fewer antiretroviral medicines. The FDA approved IDVYNSO on April 20, 2026.
What is the name of the drug and what does it do?
The medication is IDVYNSO™ (doravirine and islatravir), a once-daily oral tablet that combines two HIV medicines into a single pill. Doravirine is a non-nucleoside reverse transcriptase inhibitor (NNRTI), while islatravir is a nucleoside reverse transcriptase inhibitor (NRTI). Together, these medicines help stop HIV from making copies of itself inside the body. IDVYNSO is not a cure for HIV, but it helps keep the virus under control and protects the immune system from damage.
How does it work?
IDVYNSO works by blocking reverse transcriptase, an enzyme HIV needs to reproduce. The two medicines attack the virus in different ways, making treatment more effective and helping prevent resistance.
- Doravirine blocks reverse transcriptase directly and interferes with viral replication
- Islatravir acts like a faulty building block that interrupts HIV genetic copying
Together, these actions reduce the amount of virus in the bloodstream and help maintain long-term viral suppression. Because the two medicines work differently, they provide a complete HIV treatment regimen in one tablet.
What did the research discover?
Clinical studies showed that adults who switched to IDVYNSO maintained HIV viral suppression at rates similar to standard antiretroviral therapies. Researchers found that patients remained stable after switching from other HIV regimens.
Studies demonstrated:
- Continued viral suppression below detectable levels
- Low rates of treatment failure
- Good overall tolerability in many patients
- Simplified long-term HIV treatment with a two-drug regimen
These findings supported FDA approval for adults already successfully controlled on another HIV treatment regimen.
What are some of the side effects?
The most common side effects included:
- Dizziness
- Nausea
- Fatigue
- Headache
- Diarrhea
Some patients may also experience changes in laboratory blood tests. More serious risks can include immune system changes or severe allergic reactions, although these are less common. Patients should continue regular medical monitoring while taking HIV therapy.
What are the dosage recommendations and how is it prescribed?
The recommended dosage of IDVYNSO is one tablet taken by mouth once daily, with or without food. Patients should take the medication consistently every day to maintain viral suppression. Missing doses may increase the risk of treatment failure or drug resistance.
Doctors regularly monitor:
- HIV viral load
- CD4 immune cell counts
- Liver function
- Kidney function
- Potential drug interactions
IDVYNSO should not be used with certain medicines that strongly affect liver enzymes because these drugs can reduce treatment effectiveness.
Source:
IDVYNSO™ (doravirine and islatravir) tablets, for oral use [prescribing information]. Whitehouse Station (NJ): Merck Sharp & Dohme LLC; 2026. Available from: https://www.accessdata.fda.gov/drugsatfda_docs/label/2026/216964Orig1s000lbl.pdf. Accessed by: June 6, 2026.
