Common fever meds may ease MS fatigue and heat sensitivity

Common anti-fever medications such as aspirin and acetaminophen may help ease fatigue, improve temperature regulation, and increase exercise capacity in people with multiple sclerosis (MS), according to meta-analysis of studies.

Aspirin may be particularly effective at reducing overheating during exercise, while acetaminophen may offer greater benefits for endurance during exercise, the studies showed. Evidence for fatigue was less consistent, though some studies indicated that aspirin may help reduce fatigue symptoms.

‘This review highlights a potential adjunct therapy for nurses to incorporate into comprehensive MS care, emphasising symptom control and quality of life improvements,’ researchers wrote.

Fatigue is among the most common and disabling symptoms of MS, affecting up to 78% of patients at some point during their disease. While exercise can help manage fatigue, many people with MS are sensitive to heat and experience a temporary worsening of symptoms when their body temperature rises.

Aspirin and acetaminophen (sold as Tylenol and others) are commonly used to reduce fever and pain. These medications may also have beneficial effects in MS, helping reduce inflammation and supporting damage repair.

Yet their effects on fatigue severity, temperature regulation, and exercise tolerance have not been well explored.

Researchers in Turkey, Egypt, and Saudi Arabia reviewed data from published studies that examined the effects of aspirin and acetaminophen on these outcomes compared with a placebo or other medications used to ease MS fatigue. Seven studies involving more than 300 participants were included in the analyses.

Exercise capacity was assessed in two studies using time to exhaustion (TTE), a measure of how long a person can sustain exercise before reaching voluntary exhaustion. In one study, aspirin improved TTE by about 3% compared with a placebo, with greater benefits among participants who self-identified as ‘heat-sensitive’.

A more recent study found no significant improvement in TTE with either aspirin or acetaminophen, though acetaminophen was associated with significantly longer exercise capacity than aspirin.

The same studies also examined changes in body temperature after exercise. One study found that aspirin reduced post-exercise temperature increases by 56% among heat-sensitive participants, although the difference was not statistically significant.

Another study showed that body temperature rose significantly less after exercise with both aspirin and acetaminophen compared with a placebo, although aspirin showed the greatest benefits.

Four studies assessed fatigue using the Fatigue Severity Scale (FSS), with mixed results. One study found that adding aspirin to amantadine, a commonly used medication for MS-related fatigue, led to greater reductions in fatigue than amantadine alone. Another reported that aspirin and amantadine led to similar improvements. Two studies compared aspirin against a placebo, with one suggesting that aspirin may provide some benefit and the other finding no significant effect.

Researchers also pooled data from three studies that assessed fatigue using the Modified Fatigue Impact Scale (MFIS), a questionnaire that measures how fatigue affects daily life. While MFIS scores did not differ significantly between patients given aspirin or placebo after treatment, those who took aspirin experienced a statistically significant reduction of about 6 points, suggesting less severe fatigue.

The researchers also examined safety data and found that aspirin was generally safe and well tolerated. Most side effects were mild and temporary, including nausea, stomach discomfort, dizziness, and headache. A pooled analysis found no significant differences in adverse events between aspirin and a placebo or amantadine.

Overall, the findings suggest that oral anti-fever medications could serve as an inexpensive and accessible option to help manage fatigue and heat sensitivity in MS.

‘Further high-quality randomised controlled trials are needed to confirm these findings and optimise treatment strategies for MS-related fatigue and heat sensitivity,’ they wrote.

Read more about fatigue and how best to manage it with our trusted Choices booklet