Gabapentin Side Effects May Mimic Heart Failure Symptoms: Study

Misdiagnosing Neurontin side effects as heart failure led to new complications in one-quarter of patients, including kidney problems, electrolyte imbalances and emergency hospital visits

New research suggests many patients taking Neurontin suffer side effects that doctors do not recognize are related to the drug, often leading to additional, unnecessary treatments.

According to a study published December 2 in JAMA Network Open, some patients experiencing Neurontin side effects were misdiagnosed with heart failure, leading doctors to prescribe additional medications. Researchers found these secondary treatments caused further complications that could have been avoided if Neurontin had been discontinued instead.

Gabapentinoids, sold under brand names Neurontin and Lyrica, are a class of anticonvulsant drugs used to treat nerve-related pain, seizures and spinal cord injuries. Doctors often prescribe them “off-label” for anxiety, alcohol withdrawal, shingles and hot flashes.

However, there has been growing public concern around the misuse of Neurontin and Lyrica in recent years, with reports that some patients use the medications to enhance the effects of other drugs, replace opioids, or cope with psychological stress. In addition, an uptick in Neurontin prescriptions has coincided with increasing reports of misuse and dependence.

Data published in October 2025 indicated prescriptions for Neurontin increased by 200% over the past 15 years. As a result, some health officials have called for Neurontin to be reclassified as a controlled substance due to growing signs of widespread abuse.

For the new study, researchers from the University of California, San Francisco examined 120 veterans 66 years and older, with a focus on determining if patients had experienced “prescribing cascades” after taking gabapentin.

A prescribing cascade occurs when doctors prescribe a drug leading to patients experiencing side effects the doctors do not recognize. More drugs are then prescribed to treat the side effects, yet the new medications are often unnecessary and cause a side effect loop in patients, the researchers explained.

Led by Dr. Matthew E. Growdon, the team determined that when patients began experiencing side effects after taking gabapentin, 97% of doctors prescribed diuretics. In addition, more than 40% of doctors thought leg swelling was a symptom of heart failure, instead of a side effect of the medication.

In the two months after patients started taking diuretics to treat the heart failure doctors thought they had, one-quarter began experiencing other symptoms including worsened kidney function, electrolyte abnormalities, dizziness, blurred vision and falls. Six patients were hospitalized or treated in the emergency room for their symptoms.

Researchers also found that 20% of patients underwent unnecessary medical imaging to rule out other causes of their symptoms, instead of doctors realizing it was the gabapentin.

Only four of the veterans’ doctors considered gabapentin to be a factor in the side effects their patients experienced. While none of the patients experienced the symptoms before starting gabapentin, only one doctor ordered their patient to stop taking the drug.

The researchers determined that nearly 90% of patients in the study were taking more than five long-term medications. However, doctors did not consider medications when diagnosing their symptoms. In fact, doctors rarely noted that patients were even taking Neurontin or Lyrica in their medical records.

According to the research team, Neurontin is often prescribed at very high doses that are not needed, and for conditions that may not be typically treated by the drug. However, when side effects appear, doctors fail to consider the potential link to Neurontin or Lyrica and add more medications to treat the symptoms, the researchers concluded, stressing the importance of doctors being aware of potential prescribing cascades when patients are taking gabapentinoids.

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