Common Nerve Pain Medications May Be Triggering a Dangerous Chain of Misdiagnosis in Older Patients
Medications like gabapentin and pregabalin are widely prescribed for nerve-related pain and are often viewed as safer alternatives to opioids. But new research suggests that these drugs may be quietly setting off a troubling chain reaction in older adults—one that can lead doctors down the wrong diagnostic path and expose patients to unnecessary and potentially harmful treatments.
A study from researchers at the University of California, San Francisco (UCSF) has taken a close look at this issue and found strong evidence of what clinicians call a prescribing cascade. This happens when the side effects of one medication are mistaken for a new medical condition, prompting doctors to prescribe additional drugs that come with their own risks.
What sparked concern among researchers
The study focused on gabapentinoids, a class of drugs that includes gabapentin (sold under the brand name Neurontin) and pregabalin (Lyrica). These medications are commonly used to treat nerve pain, seizures, restless leg syndrome, and sometimes anxiety. Over the past decade, their use has nearly doubled, especially among older adults.
Despite their reputation as relatively safe, gabapentinoids are known to cause peripheral edema, or swelling in the legs and feet. That symptom can look a lot like heart failure, a serious condition that also causes fluid buildup in the lower extremities. According to the UCSF researchers, this visual similarity is where problems often begin.
Inside the study
Researchers reviewed the medical records of 120 older U.S. veterans, most of whom were men and were already taking five or more long-term medications. All of the patients had been prescribed a gabapentinoid and later went on to receive a loop diuretic, a type of drug used to reduce fluid buildup when heart failure or similar conditions are suspected.
Importantly, none of these patients had a diagnosis of heart failure or venous stasis—another circulation-related condition—during the year before they started taking gabapentinoids. Yet once swelling appeared, doctors frequently looked for new diseases instead of questioning the medication.
Only four physicians considered gabapentinoids as a possible cause of the swelling. In contrast, 69 physicians attributed the symptom to other medical conditions, most commonly heart failure or venous stasis. Even when doctors suspected the drug might be involved, almost all still moved forward with prescribing diuretics.
Perhaps most striking is that only one doctor actually discontinued the gabapentinoid, despite the clear timeline linking the drug to the onset of swelling.
When treatment causes more harm than help
Once diuretics such as Lasix were added, many patients began experiencing new problems. Within two months, 28 patients developed symptoms that were likely related to the diuretics rather than an underlying disease.
These issues included:
- Worsening kidney function
- Low sodium or potassium levels, which can interfere with essential body processes
- Dizziness and lightheadedness
- Blurred vision
- An increased risk of falls
In six cases, patients were hospitalized or evaluated in the emergency department because of these complications. What began as a side effect from one medication had turned into a serious medical situation involving multiple drugs and escalating risks.
This is the core danger of a prescribing cascade: each new medication is added with good intentions, but the overall effect can be worse health outcomes, especially for older adults.
Why older adults are especially vulnerable
Older patients are more likely to have multiple chronic conditions, which often leads to polypharmacy, or the use of many medications at the same time. With every additional drug, the risk of side effects, interactions, and misinterpretation increases.
Swelling in the legs of an older person can understandably raise red flags for clinicians. Heart failure is common in this age group and can be life-threatening if missed. But the study shows that in the rush to rule out serious disease, doctors may overlook a simpler explanation: the medication itself.
The research also found that nearly one in five patients underwent imaging or other diagnostic tests to rule out dangerous conditions, even though the swelling appeared only after starting gabapentinoids.
Rethinking how gabapentinoids are prescribed
The study’s authors emphasize that gabapentinoids are often prescribed at higher doses than necessary or for conditions where their benefits are uncertain. While they can be helpful for some patients, they are not risk-free, especially when used long-term.
The researchers suggest several practical steps clinicians can take:
- Regularly reassess whether gabapentinoids are still needed
- Consider lower doses, particularly in older adults
- Be alert to side effects that mimic other diseases
- Explore non-drug alternatives for pain management when appropriate
For patients, the takeaway is equally important. Anyone taking gabapentin or pregabalin—especially older adults—should check in regularly with their healthcare provider and report new symptoms like swelling, dizziness, or changes in balance.
A closer look at gabapentin and pregabalin
Gabapentin and pregabalin were originally developed as anti-seizure medications, but their ability to calm nerve signals led to widespread use for chronic pain. Because they are non-opioid, they are often seen as a safer choice amid concerns about addiction and overdose.
However, both drugs affect the nervous system and can cause side effects such as sedation, confusion, balance problems, and swelling. Pregabalin, in particular, has been linked in other large studies to a higher risk of heart failure events, especially in people with existing cardiovascular disease.
This does not mean these medications should never be used. Rather, it highlights the need for careful prescribing and ongoing monitoring, especially in populations that are already medically complex.
Why this study matters
What makes this research especially valuable is that it looks beyond individual side effects and focuses on real-world clinical decision-making. It shows how easy it is for well-meaning doctors to follow a logical but flawed path when a drug reaction looks like a new illness.
The findings also underscore a broader issue in modern medicine: symptoms are not always new diseases. Sometimes, they are signals that a treatment needs to be reconsidered.
By drawing attention to prescribing cascades, this study encourages clinicians to pause and ask a critical question before adding another medication: Could this be caused by something the patient is already taking?
That simple step could prevent unnecessary testing, reduce hospitalizations, and spare patients from avoidable harm.
Research paper:
https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2842165
