Long on Meds Blog

Additional Evidence: Could Generic Medications Help Treat Alzheimer's Disease?

By Mark Gostine, MD

Researchers are investigating whether familiar generic medications can do double duty: treat the conditions for which they were approved while also affecting processes involved in other diseases. Recent findings involving the HIV medication lamivudine raise questions about Alzheimer's disease and multiple sclerosis. The evidence is promising, but not yet proof of a treatment benefit.

1. Is there any research supporting repurposing generic medications for central nervous system disorders such as multiple sclerosis or Alzheimer's disease?

Yes, but most of it is still early research. Studies in animals, large medical-record databases, and a small human trial suggest that certain medications originally developed for HIV may influence inflammation and nerve injury. None has been shown in a large randomized trial to prevent or treat Alzheimer's disease or multiple sclerosis.

2. Which existing generic medications are being investigated?

One is lamivudine (3TC), an established generic antiviral medication used for HIV and hepatitis B. Related generic medicines include emtricitabine, zidovudine, and tenofovir disoproxil fumarate. These belong to a class called nucleoside or nucleotide reverse transcriptase inhibitors (NRTIs).

Other medications, including metformin and pioglitazone, have also been studied for possible neurological effects. But a result involving one drug does not mean that every drug in the same class will work the same way.

3. How might these medications protect the brain?

Alzheimer's disease and multiple sclerosis are different illnesses, but inflammation can contribute to injury in both. In Alzheimer's disease, inflammation interacts with abnormal amyloid and tau proteins. In multiple sclerosis, immune cells attack myelin, the protective covering around nerve fibers.

Lamivudine can block an enzyme used by certain genetic elements whose activity may contribute to inflammation. Laboratory studies also suggest that some NRTIs can affect inflammasomes, cellular systems that amplify inflammatory signals. These are possible pathways for protection, not proof that the drug improves neurological outcomes in patients.

4. What have researchers discovered about lamivudine and other HIV medications?

In aging mice, lamivudine improved performance on some memory tests and reduced signs of brain inflammation. Another mouse study reported less tau-related injury.

In a 2025 human pilot study, 12 people with early Alzheimer's disease received lamivudine for 24 weeks. Cognitive measurements were generally stable, and researchers observed changes in certain biomarkers, including one associated with brain inflammation. But there was no placebo group. We cannot know whether the drug caused the stability or whether similar patients without treatment would have had the same results.

In medical-record studies, patients exposed to NRTIs had lower recorded rates of Alzheimer's disease. Such observational findings can help generate hypotheses, but they cannot establish cause and effect.

In multiple sclerosis research published in 2026, an experimental NRTI-derived compound called K-9 reduced nerve injury and improved function in mice with an MS-like illness. Researchers also observed an association between NRTI use and lower MS incidence in human records. K-9 is not lamivudine, and neither has been proven to treat MS in humans.

5. Could combining medications provide greater protection?

Possibly. Neurological diseases involve several processes, including inflammation, abnormal protein accumulation, and damage to nerve cells. Treatments that act on different pathways could eventually complement each other.

This is one of the ideas explored in Long on Meds: choosing medications not only for the condition being treated but also considering additional benefits to other tissues and organs. Yet combinations must be tested. More medications do not automatically mean better outcomes, and added drugs can bring added risks.

The goal is not more medications. It is better choices based on demonstrated benefits and acceptable risks.

6. How should patients and physicians evaluate repurposed generic medications alongside established Alzheimer's treatments? Could they eventually be used together?

For families facing Alzheimer's disease, the distinction between proven but limited benefit and promising but unproven benefit matters.

Leqembi (lecanemab), an approved antibody treatment, targets amyloid in the brain. In a large randomized study of people with early Alzheimer's disease, it slowed worsening on a cognitive and functional measure by about 27% relative to placebo over 18 months. It did not stop progression. Leqembi can cause amyloid-related brain swelling or bleeding, sometimes serious, and requires MRI monitoring.

Lamivudine works differently. It does not target amyloid with an antibody. Its possible effects on inflammation and related biological processes are being studied. It is not known to cause the characteristic amyloid-related imaging abnormalities of anti-amyloid antibodies, but it has other risks, including rare serious toxicity, kidney-related dosing considerations, and complications involving hepatitis B or HIV.

The 24-week lamivudine pilot was encouraging enough to justify further research. It cannot be compared directly with lecanemab's large controlled trial, and stable scores in 12 participants do not prove that lamivudine slowed or stopped Alzheimer's disease.

Could both treatments eventually be used together? Their different mechanisms make this a reasonable research question. However, adequate clinical trials have not established whether the combination improves outcomes or is safe.

Lamivudine is approved for specific viral infections, not Alzheimer's disease or multiple sclerosis. Patients and families can discuss the research and clinical trial opportunities with their neurologist. Experimental options should not delay evaluation for treatments with demonstrated benefits when appropriate.

The larger lesson is that existing generic drugs may have useful effects beyond their original indications. Finding out which additional benefits are real, and for whom, is an important opportunity for clinical research.

Selected scientific references

Fowler BJ, et al. Nucleoside reverse transcriptase inhibitors possess intrinsic anti-inflammatory activity. Science. 2014. Original study.
Wahl D, et al. The reverse transcriptase inhibitor 3TC protects against age-related cognitive dysfunction. Aging Cell. 2023. Original study.
Vallés-Saiz L, et al. Lamivudine and neuropathological changes in mutant tau transgenic mice. International Journal of Molecular Sciences. 2023. Original study.
Sullivan AC, et al. A Phase IIa clinical trial to evaluate the effects of anti-retroviral therapy in Alzheimer's disease (ART-AD). npj Dementia. 2025. Original study.
Magagnoli J, et al. Association of nucleoside reverse transcriptase inhibitor use with reduced risk of Alzheimer's disease. Alzheimer's & Dementia. 2025. Original study.
Yerramothu P, et al. The nucleoside analog kamuvudine-9 shows protective and therapeutic efficacy in a mouse model of multiple sclerosis. Science Translational Medicine. 2026. Original study.
U.S. Food and Drug Administration. Leqembi prescribing information.

Medical information: This article is for education only. It does not recommend using HIV medications to treat or prevent Alzheimer's disease or multiple sclerosis. Medication decisions require individualized medical evaluation and physician supervision.

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