Only option sits at the center of this dementia and brain health question.

When a patient in a hospital intensive care unit develops a bloodstream infection caused by *Candida auris* — a fungal superbug that shrugs off nearly every antifungal drug available — doctors often find themselves reaching for one of the oldest and most punishing medications in the pharmacy: amphotericin B. This polyene antifungal, in use for more than 60 years, has become the last line of defense against pan-resistant strains of C. auris that have already defeated azoles and echinocandins, the two drug classes clinicians would normally try first. It is, in many cases, the only option left — and it comes with a brutal tradeoff, because amphotericin B can cause life-threatening kidney damage in the very patients it is trying to save. The situation is getting worse. The CDC has classified C.

auris as an urgent antimicrobial resistance threat, and the numbers bear that out: from just 323 clinical cases reported in 2018, the count surged to 6,304 in 2024 and approximately 7,000 across dozens of U.S. states in 2025. Roughly 30 to 60 percent of patients with invasive C. auris infections die, though co-existing medical conditions make it difficult to pin down exactly how many deaths the fungus itself causes. For families caring for loved ones with dementia or other conditions that require long-term healthcare facility stays, the spread of this organism is a particularly urgent concern. This article examines why amphotericin B remains the fallback antifungal, what makes C. auris so difficult to treat, and what new drugs and research breakthroughs may finally offer alternatives.

Why Is Amphotericin B the Only Antifungal Option for Drug-Resistant Candida Auris?
How Candida Auris Spreads in Healthcare Facilities — and Why Dementia Patients Face Higher Risk
The New Antifungals Finally Reaching Patients After Decades of Drought
Combination Therapy — Can Pairing Old Drugs Beat Resistance?
Research Breakthroughs That Could Change the Game — But Haven’t Yet
What Families of Dementia Patients Should Ask Their Care Facility
Where the Fight Against Candida Auris Goes From Here
Conclusion

Why Is Amphotericin B the Only Antifungal Option for Drug-Resistant Candida Auris?

The answer lies in a simple math problem: medicine has remarkably few antifungal drug classes to work with. While antibiotics for bacterial infections come in dozens of classes, only three to four major classes of antifungals exist — azoles, echinocandins, polyenes, and the newer triterpenoids. C. auris has proven adept at developing resistance to all of them. Some strains are classified as pan-resistant, meaning no standard antifungal works reliably. When azoles fail and echinocandins fail, amphotericin B — the lone polyene antifungal in widespread clinical use — is what remains. Amphotericin B works by binding to ergosterol in the fungal cell membrane, essentially punching holes in the organism until it dies. It has maintained relatively low clinical resistance rates over its six decades of use, which is partly why it endures as a last resort. But the drug earned the grim nickname “ampho-terrible” among clinicians for good reason.

Its nephrotoxicity — the tendency to damage kidneys — is not a rare side effect but an expected one at therapeutic doses. For an elderly patient with dementia who may already have compromised kidney function, this creates a genuinely agonizing clinical decision. Newer lipid formulations of amphotericin B have reduced but not eliminated this toxicity. The comparison to antibiotics is instructive. When a bacterial infection resists first-line antibiotics, physicians can typically cycle through numerous alternative classes. With C. auris, once azoles and echinocandins are off the table, the medicine cabinet is nearly bare. And here is the part that should alarm everyone: approximately 33 percent of C. auris isolates now show resistance to amphotericin B as well. The last resort is losing its effectiveness.

Why Is Amphotericin B the Only Antifungal Option for Drug-Resistant Candida Auris?

How Candida Auris Spreads in Healthcare Facilities — and Why Dementia Patients Face Higher Risk

C. auris spreads readily in hospitals and long-term care facilities, which is exactly where the most vulnerable patients spend their time. The fungus can persist on surfaces for weeks, resists common disinfectants, and colonizes skin without causing symptoms — meaning a patient or healthcare worker can carry and spread it unknowingly. Standard cleaning protocols that work against other pathogens often fail against C. auris, requiring specialized disinfection procedures that not all facilities have adopted. For people living with dementia, the risk factors compound. Dementia patients in long-term care facilities often have central venous catheters, urinary catheters, or feeding tubes — all of which serve as entry points for fungal infection. They may be on broad-spectrum antibiotics for other infections, which disrupt the body’s natural microbial balance and create openings for fungal colonization.

Their immune systems may be weakened by age, malnutrition, or other chronic conditions. And critically, they may be unable to communicate symptoms of a developing infection, delaying diagnosis until the organism has already entered the bloodstream. However, it is important to note that C. auris does not typically threaten healthy individuals. The risk is concentrated among people who are already hospitalized or in long-term care, who have invasive medical devices, or who have weakened immune systems. A family member visiting a loved one in a care facility is at extremely low risk of developing a C. auris infection themselves — but they should absolutely ask the facility about its infection control protocols, especially if there have been cases reported in the region. The CDC tracks C. auris cases by state, and that data is publicly available.

The New Antifungals Finally Reaching Patients After Decades of Drought

After more than twenty years without a truly new antifungal class, the pipeline has started to move. The most significant recent approval is rezafungin, marketed as Rezzayo, which the FDA approved on March 22, 2023, for the treatment of candidemia and invasive candidiasis. Rezafungin is the first new echinocandin approved in over a decade and offers a meaningful practical advantage: once-weekly dosing instead of daily intravenous infusions. Research published in the Oxford Academic journal *Journal of Antimicrobial Chemotherapy* has shown potent activity across all six known clades of C. auris, suggesting it could be effective against strains from different geographic origins. Another newcomer is ibrexafungerp, sold as Brexafemme, which received FDA approval in June 2021 and represents the first entirely new antifungal drug class — the triterpenoids — in more than two decades. Its Phase 3 MARIO study for invasive candidiasis was expected to resume in early 2025. Unlike the echinocandins, ibrexafungerp is orally administered, which could be a significant advantage for outpatient treatment and step-down therapy after initial hospitalization.

Then there is fosmanogepix, currently in Phase 2/3 trials, which has received FDA Fast Track designation for seven different fungal indications. Phase 2 data showed 89 percent treatment success and survival in candidemia patients — a striking figure, though larger trials will be needed to confirm it. The Phase 3 FORWARD-IM study was expected to begin in the second quarter of 2025. For dementia patients and their families, these drugs represent genuine hope — but with an important caveat. Approval does not guarantee access. New antifungals are expensive, and not every facility will stock them immediately. Pan-resistant C. auris strains may require combination approaches that are still being studied.

The New Antifungals Finally Reaching Patients After Decades of Drought

Combination Therapy — Can Pairing Old Drugs Beat Resistance?

When a single antifungal cannot kill a resistant organism, researchers have increasingly turned to combination therapy — using two drugs together in the hope that their combined mechanisms will overwhelm the fungus’s defenses. This approach has shown real promise against C. auris, though it comes with tradeoffs that clinicians must weigh carefully. One of the more intriguing findings involves rolapitant, an existing anti-nausea drug that was never designed to fight fungi. Researchers discovered that rolapitant has potent synergistic interactions with amphotericin B against C. auris, potentially overcoming resistance that would defeat either agent alone.

The appeal of repurposing an already-approved drug is significant: it could shorten the path to clinical use by years compared to developing a new compound from scratch. Separately, a study published in *The Lancet Microbe* found that combining micafungin (an echinocandin) with amphotericin B produced synergistic antifungal effects in eight of ten C. auris isolates tested — meaning the drugs together performed far better than either would alone. The tradeoff is toxicity. Amphotericin B already taxes the kidneys, and adding a second drug means monitoring for additional side effects and drug interactions. For a frail, elderly patient with dementia and multiple medications, the risk-benefit calculation is genuinely difficult. Combination therapy may save a patient’s life when nothing else will, but it demands close monitoring by experienced infectious disease specialists — a resource that not all long-term care facilities have readily available.

Research Breakthroughs That Could Change the Game — But Haven’t Yet

In January 2026, researchers at McMaster University published a discovery that generated significant attention: a molecule called butyrolactol A that weakens both *Cryptococcus neoformans* and C. auris by blocking an essential protein complex within the fungi. The concept is compelling — rather than killing the fungus directly, butyrolactol A could strip away its defenses and allow existing antifungal drugs to work again against resistant strains. It is a fundamentally different approach, akin to disarming an opponent rather than trying to overpower them. The limitation that families and patients need to understand, however, is the long road between a laboratory discovery and a usable medication. Butyrolactol A has been demonstrated in research settings, not in clinical trials with human patients.

The history of drug development is filled with molecules that showed extraordinary promise in the lab and then failed in human testing due to toxicity, poor absorption, or simple ineffectiveness at achievable doses. Even under accelerated timelines, it could be years before butyrolactol A or similar compounds become available for clinical use. This gap matters urgently because C. auris is not waiting. The number of clinical cases is climbing year over year, resistance to amphotericin B is increasing, and the populations most at risk — elderly, immunocompromised patients in healthcare facilities — cannot afford to wait for the next generation of drugs. Every month of delay means more patients facing infections with no good treatment options.

Research Breakthroughs That Could Change the Game — But Haven't Yet

What Families of Dementia Patients Should Ask Their Care Facility

If your loved one is in a long-term care facility or hospital, especially in a state where C. auris has been reported, there are specific questions worth raising with the medical staff. Ask whether the facility has had any C. auris cases or colonization events. Ask what disinfection protocols are used — C.

auris requires specific agents, and standard hospital cleaning may not be sufficient. Ask whether patients are screened for C. auris colonization on admission, particularly if they are transferring from another healthcare facility. These are not alarmist questions. The CDC actively recommends that healthcare facilities in affected areas conduct surveillance screening and implement enhanced infection control measures. Families have every right — and good reason — to understand what protections are in place, especially for patients who cannot advocate for themselves.

Where the Fight Against Candida Auris Goes From Here

The trajectory of C. auris over the next several years will likely be shaped by two competing forces. On one side, the fungus continues to spread and evolve resistance, with the proportion of pan-resistant strains gradually increasing. The jump from 323 cases in 2018 to roughly 7,000 in 2025 suggests this organism is far from contained, and climate change — which may be helping C. auris adapt to human body temperatures — could accelerate its spread further. On the other side, the antifungal pipeline is more active than it has been in decades.

Rezafungin is already available. Ibrexafungerp and fosmanogepix are advancing through late-stage trials. Combination strategies and novel approaches like butyrolactol A offer pathways around existing resistance. The question is whether these new tools will arrive and reach bedside use fast enough to keep pace with a pathogen that has consistently outrun our defenses. For the families of dementia patients and others in long-term care, the most practical thing to do right now is stay informed, ask direct questions of healthcare providers, and push for the infection control measures that are already proven to slow C. auris transmission.

Conclusion

Amphotericin B remains, for now, the antifungal of last resort against pan-resistant *Candida auris* — a position it holds not because it is a good option, but because it is frequently the only one left. Its kidney toxicity, its age, and the slowly rising rates of C. auris resistance to it make clear that relying on a single 60-year-old drug against an evolving superbug is not a sustainable strategy. The fact that only three to four classes of antifungal drugs exist, compared to the dozens available for bacterial infections, underscores how narrow the margin of safety really is.

The arrival of rezafungin, the advancement of ibrexafungerp and fosmanogepix through clinical trials, and laboratory breakthroughs like butyrolactol A and rolapitant repurposing offer real grounds for cautious optimism. But optimism does not treat patients today. For families navigating dementia care in long-term facilities, the practical steps are concrete: understand the risk C. auris poses in healthcare settings, ask facilities about their infection control and screening practices, and stay aware of CDC guidance as it evolves. The fight against drug-resistant fungi is ultimately a race — and right now, the fungus is setting the pace.