The Drug That's Being Used To Combat 'Brain-Eating Amoeba' In Kerala

Kerala is reeling under an alarming increase in deadly infections from Naegleria fowleri, often called the "brain-eating amoeba", which causes Primary Amoebic Meningoencephalitis (PAM), a rare but almost always fatal brain infection. In 2025 alone, the state has reported some 69 confirmed cases with 19 deaths so far. The alarming trend is not just in numbers: what is notable is that Kerala's survival rate has improved sharply, estimated around 24%, much higher than the global survival rate of under 3%. One of the key changes in management has been the use of miltefosine as part of early, aggressive therapy in PAM cases.

Combined with other drugs, intensified supportive care, and efforts like public awareness and better diagnostics, health authorities are attempting to reduce the fatality that usually occurs within 5-10 days of symptom onset. In Kerala, miltefosine is being deployed alongside standard treatments like amphotericin B, often as soon as PAM is suspected, to try and tilt the balance in favour of survival. So what has made this drug so effective, and what should patients know more about its usage? Here's what you need to know.

Miltefosine Use In Kerala: Recent And Historical Data On PAM

To understand how miltefosine is helping, it's useful to parse what is known from published research and how Kerala's recent data fit in.

Global Baseline For PAM

PAM has a mortality rate exceeding 95-98%. The median time from symptom onset to death is very short, around 5 days in many documented cases, as reported by researchers Najwa Pervin and Vidya Sundareshan from Kerala on the NCBI portal.

Previous Studies On Miltefosine For PAM

A global review (Grace et al., 2015) of PAM treatment notes that miltefosine has been used in several case reports, often in combination with other drugs. However, most patients treated still did not survive, likely due to late diagnosis.

Kerala's Recent Experience With PAM

Cases have been more numerous and show wider geographic spread in 2024-2025. The improved survival (approximately 24%) is attributed to earlier recognition of PAM, more aggressive multimodal therapy (including miltefosine), better hospital care, and possibly faster access to diagnostics.

Limitations In Data On Miltefosine Use

There are no large randomized controlled trials for miltefosine in PAM. Many reports are case studies or small series. Because PAM progresses so rapidly, even small delays in institution of therapy severely reduce the chance of survival. Kerala's data are relatively recent and still being gathered in more detail.

What Is Miltefosine?

Miltefosine is an antiparasitic (and some might say historically experimental) drug, originally developed for cancer, later repurposed for leishmaniasis. It is an alkylphosphocholine compound, interfering with parasite cell membranes and, in certain organisms, internal cell signalling/apoptosis-like pathways.

Because of its ability to cross cellular membranes and its wide spectrum of action against protozoan parasites, it has been explored, in vitro and in limited clinical settings, for free-living amoebae like Acanthamoeba, Balamuthia, and Naegleria fowleri.

Evolution Of Miltefosine Use: From Cancer To Leishmaniasis To PAM

• Initial development: Miltefosine was first synthesised and tested as an anti-neoplastic agent (anti-cancer). Early experiments showed cytotoxicity in certain tumour lines. However, toxicity and side-effect profiles made its use in oncology limited.
• Leishmaniasis: Miltefosine found its first large-scale and lasting use in visceral leishmaniasis and cutaneous leishmaniasis, where it has become one of the standard oral treatments in many endemic countries, including India. Cure rates for visceral leishmaniasis in controlled settings have been quite good (often 70-90%), depending on dose, region, and parasite species.
• Free-living amoebae (including Naegleria): Miltefosine has been used off-label or in investigational protocols, often alongside other drugs, in a few documented PAM survivors, particularly in North America.

Dosages Used In PAM Cases: What Kerala Is Likely Following

Because there is no universally approved regimen for PAM with miltefosine, what exists are guidelines, case reports, and inferred weight-based dosing. In Kerala, although specific patient-by-patient protocol details are not all in public domain yet, the reports suggest that miltefosine is being used early, orally, in combination with other known anti-amoebic agents (like amphotericin B), intensive supportive measures (monitoring intracranial pressure, etc.). The US CDC provides recommendations, which Kerala hospitals are likely adapting:

• For adults (weighing 45 kg or more), typically 50 mg three times daily, taken orally with food.
• For children (weighing less than 45 kg), lower doses, around 50 mg twice daily or adjusted by weight.
• Duration of therapy is usually 28 days or longer, depending on patient response.
• Always given as part of a combination, with amphotericin B, azoles, rifampin, and strong supportive care.

Why Miltefosine May Be Working In Kerala Now

Several factors combine to make Kerala's improved survival plausible:

• Earlier detection and faster initiation of therapy
• Physicians are now more alert to the possibility of amoebic meningoencephalitis in patients with meningitis-like symptoms and recent freshwater exposure. Delays in past cases have been a big problem globally.
• Combination therapy: Miltefosine is not used alone but along with amphotericin B (IV, sometimes intrathecal), azoles or other anti-amoebic agents. This multipronged attack increases chances of survival and recovery.
• Improved supportive care: ICU care, attention to brain swelling (intracranial pressure), management of seizures, etc. Better hospital infrastructure helps.
• Higher awareness and public health measures: Government initiatives like chlorination drives, warnings, and better environmental surveillance, leading to prevention and early medical presentation.
• Temperature and environmental factors: Warm freshwater favours Naegleria fowleri. Kerala's climate plus monsoon and possibly warming trends have increased the amoeba load, but at the same time, this drives awareness and health systems to respond earlier.

Side Effects Of Miltefosine: Why Caution Matters

While miltefosine has promise, it also has side effects, and treating PAM is fraught with risks. Patients and caregivers should be aware of the following.

Common Or Moderate Side Effects:

• Gastrointestinal issues: Nausea, vomiting, diarrhoea, abdominal pain. These are perhaps the most frequent.
• Dehydration due to vomiting/diarrhoea.
• Renal (kidney) effects: Miltefosine is mildly nephrotoxic; dosing adjustments or close monitoring needed if kidney function is impaired.
• Hepatic (liver) involvement: Elevated liver enzymes; sometimes more serious.

Less Common Or Serious Side Effects:

• Electrolyte disturbances.
• Potential for longer-term toxicity (in leishmaniasis programs, some reproductive concerns, etc.).
• Since PAM patients often are critically ill, many side effects may overlap with effects of the infection itself or other drugs.

Special Notes And Cautions For Miltefosine Use

Although miltefosine is being used to treat PAM in Kerala currently, one must take the following warnings seriously:

• Miltefosine use is only done with medical supervision, constant monitoring and in very rare cases, like with PAM cases in Kerala. The drug is not available over-the-counter and is prescribed by doctors only in the rarest cases.
• There is no guarantee of survival even with prompt treatment. Miltefosine improves odds but PAM remains a very serious illness.
• The evidence is based largely on case reports and small patient series rather than large clinical trials, especially in Indian context.
• Drug availability, regulatory approvals, and timing are critical. In many previous settings, delays in getting miltefosine delayed treatment beyond what could be effective.
• Because the drug can be teratogenic or have effects in pregnancy, women of childbearing age need counselling and perhaps pregnancy tests; avoid if pregnant unless in life-saving scenario.
• Real public health prevention remains crucial: Chlorination of water bodies, avoiding exposure of nose to untreated warm freshwater, safe nasal rinsing practices.

The surge in brain-eating amoeba cases in Kerala is deeply concerning. Yet, the use of miltefosine as an early part of combined therapy, along with improved diagnostics, awareness, and supportive hospital care, offers a ray of hope. While the drug is not a silver bullet and has side-effects, when used correctly, it has increased survival from near-zero to notable levels. Moving forward, prevention (clean water, safe practices) plus readiness in medical systems are required to stem this crisis.

Disclaimer: This content including advice provides generic information only. It is in no way a substitute for a qualified medical opinion. Always consult a specialist or your own doctor for more information. NDTV does not claim responsibility for this information.

References:

Grace E, Asbill S, Virga K. Naegleria fowleri: pathogenesis, diagnosis, and treatment options. Antimicrobial Agents and Chemotherapy. 2015. doi:10.1128/AAC.01293-15.

Cope JR, et al. Use of the Novel Therapeutic Agent Miltefosine for the Treatment of Primary Amebic Meningoencephalitis: Report of 1 Fatal and 1 Surviving Case. Clin Infect Dis. 2016;62(6):774-6.

Subbaram K, Faiz R, Un Naher Z, Manandhar PL, Ali S. Cases of brain eating amoeba in India: Primary amoebic meningoencephalitis clinical features and pathogenesis. 2024. PMC11490792.

Centers for Disease Control and Prevention (CDC). Clinical Care of Naegleria fowleri Infection (2025 update).

Alli A, et al. Miltefosine: A Miracle Drug for Meningoencephalitis ... PMC8020194, 2021.

WHO / other published pharmacovigilance data from Indian leishmaniasis programmes on miltefosine side effects.