Some can increase your risk
By UNIVERSITY OF SYDNEY
The findings highlight the potential for some of these medicines to join the fight against old and new infectious diseases.
Although research into these drugs has focused on their effects on pain and fever management, until now, their impact on the treatment of infectious diseases specifically was unclear.
The findings highlight the need
for more studies in this under-recognized area of research, with wide-reaching
implications.
Key findings of the clinical review
For pain: Morphine suppresses key cells of the immune system and
increases the risk of infection, particularly after cancer surgery.
For fever: Antipyretics – e.g. Paracetamol, Ibuprofen, Aspirin –
can reduce the desirable immune response when taken for vaccination.
Aspirin could be an affordable and accessible therapeutic option
for tuberculosis – which mainly afflicts poor countries, with beneficial
results shown in animals and humans.
Anti-inflammatory medicine indomethacin may reduce viral
replication in Covid-19 but large-scale human trials are needed.
Researchers led by the University of Sydney’s Faculty of Medicine
and Health opted for a ‘clinical’ review in order to have a broader scope to
synthesize the available evidence, noting the importance of further research
and trials regarding infectious disease responses.
The research was unplanned and the findings unexpected, with lead
author Christina Abdel-Shaheed saying they initially were interested in
studying possible impacts of paracetamol (acetaminophen) during the pandemic,
when people hoarded the drug in the first months of COVID-19.
“We decided to study painkillers and fever medications generally
and were amazed by what we found,” she said.
“In 14 years of studying pain, this is the most important research
I have been involved in.”
The findings are published today in a leading journal, the British Journal of Clinical Pharmacology.
Caution
urged during the pandemic
Pain researcher Dr. Christina Abdel-Shaheed, from Sydney
Musculoskeletal Health, said the relationships uncovered with infectious
diseases highlighted the need for rigorous clinical trials.
“Our review shows some of the common pain and fever medications
may work with the immune system to fight infection, whereas others work against
it and increase the risk of contracting or responding badly to infectious
diseases,” Dr. Abdel-Shaheed said.
“Taking paracetamol or ibuprofen before or immediately after
vaccination – for example for COVID-19 – to try to prevent mild fever or
headache is not recommended, because this could reduce the body’s desirable
immune response to the vaccine.
“For chickenpox, use of ibuprofen is not recommended as it might
increase the risk of secondary bacterial skin infections.”
Dr. Justin Beardsley, infectious disease specialist at Westmead
Hospital and researcher with Sydney Institute for Infectious Diseases, said an
important finding of this review during the pandemic was that: “morphine – one
of the most commonly used opioid analgesics in post-surgical and critical care
– suppresses key innate immunity cells, thereby increasing the risk of
infection”.
He highlighted: “This is particularly the case with cancer
patients, who are already vulnerable to COVID-19.
“Efforts are needed to achieve adequate analgesia whilst avoiding
immune-suppression in the immediate postoperative period caused by opioids such
as morphine — both for people undergoing cancer surgery as well as for the
immunocompromised generally,” said Dr. Beardsley, who also works with the
Westmead Institute for Medical Research.
Positive
impacts on our immunity
Professor Andrew McLachlan said on the positive side, the findings
provide new insights for further research to evaluate these commonly used
medicines, which could be repurposed to improve outcomes for people undergoing
treatment for infectious diseases.
“With the urgent need for new treatments for COVID-19 and the
declining efficacy of some antimicrobial agents due to resistance, now more
than ever we need medicines which can maintain or enhance the efficacy of
anti-infective drug treatments, said Professor McLachlan, the Head of School
and Dean of Pharmacy at the University of Sydney.
“The results of this review suggest that commonly used medicines
for pain and fever should be further explored as inexpensive and effective
adjunctive treatments which influence immune and inflammation pathways for
people undergoing treatment for infection.”
Under-researched
area
Co-author Professor Ric Day from UNSW and St Vincent’s Hospital
said research was still catching up in this new area of study.
“One of the problems is that widely used medicines –such as
paracetamol, nonsteroidal anti-inflammatory drugs like ibuprofen, and
corticosteroids such as prednisone – have been around for decades and in the
past we didn’t tend to consider their impacts on the immune system because it
has been an under-recognised area.
“From community use to hospital and acute care, these classes of
pain and fever medications are among the most popular drugs worldwide but we
need to consider the significant impact these can have on our immune system and
our response to infectious diseases, including COVID-19.”
Reference: “Immunomodulatory effects of pharmaceutical opioids and
antipyretic analgesics: Mechanisms and relevance to infection” 1 March
2022, British Journal of Clinical Pharmacology.
DOI: 10.1111/bcp.15281