This post is a version of a section of “Down memory lane: Four decades of building drug safety“, published by yours truly in Uppsala Reports #75, April 2017.
In the latest issue of Uppsala Reports, pharmacovigilance expert Sten Olsson discusses the role medicines safety has to play in public health schemes.
As medicines and vaccines have become more accessible throughout the world, the need for solid surveillance systems of pharmaceutical products and their side effects has also become more urgent.
In the early days of the global safety surveillance that started in the wake of the thalidomide disaster, only high-income countries paid much attention to side effects of medicines. After all, other countries still struggled to secure access to medicines in the first place. WHO’s side effect surveillance initiative, the WHO Programme for International Drug Monitoring, was first piloted in 1968. It wasn’t until nearly a decade later, in 1977, that WHO’s Essential Medicines Programme (EMP) – a list of medicines “that satisfy the priority healthcare needs of the population” – was launched. To date, EMP has come a long way to make more of the most crucial medicines accessible in low- and middle-income countries.
“In the 1980s, many of these countries just didn’t have the medicines, and if you don’t have the medicines then you don’t have the problem of adverse drug reactions,” said Sten Olsson, president of the International Society of Pharmacovigilance and recently retired expert at Uppsala Monitoring Centre, WHO’s Collaborating Centre for International Drug Monitoring that runs the namesake surveillance programme.
“In the 1990s when countries had access to medicines, they also had to face the consequences,” Mr Olsson explained. “That was also when we first started to learn about counterfeit medicines, and all the problems that are associated with the inappropriate management of drug supplies and so on.”
The science of pharmacovigilance focuses on noting down, collecting, and analysing reports of suspected side effects to medicines, with the goal to determine if a certain ailment in a patient is caused by one medicine or a combination of drugs that they take, or if its caused by other factors. The method of recording signs of potential side effects if and when they emerge is called spontaneous reporting.
It seems simple enough, and the notion that pharmacovigilance has a function to fill in all well-functioning healthcare systems shouldn’t be controversial. However, the scientific validity of spontaneous reporting has long been questioned in the wider scientific community. Observations of potential adverse drug reactions provide no certain causality, and the lack of control groups and information about the number of people exposed may cast doubt on the research that stems from these observations.
“From the beginning, this whole issue of collecting clinical observations – individual observations of patients and the suspicions of medicines being associated with harm – has been questioned by researchers”, Mr Olsson said. “But we know that the vast majority of all regulatory decisions on safety are based on spontaneous reports, on observations by clinicians, by healthcare professionals, and by patients. It is the most sensitive method we have to find new, rare, and serious adverse drug reactions.”
The last 15 years have brought about much effort to establish pharmacovigilance within public health programmes focused on, for example, HIV/AIDS, malaria, and tuberculosis around the world.
“Public health programmes are so focused on treating populations and reducing the burden of disease and mortality that they have a disregard for collateral damage caused by their interventions. And that’s where pharmacovigilance has another entry point, because we are concerned about the safety of the individual patient,” Mr Olsson said.
“I can accept that as a public health programme manager, you’re very concerned about the confidence of the programme – they don’t want to talk about anything that might jeopardise the confidence, because then people might not take their medicines or their vaccines.”
Using HIV/AIDS programmes as an example on how that attitude can backlash, Mr Olsson said: “When they started it was all about access, access, access to medicines. They distributed medicines to places where there were absolutely no educated people to help support patients receiving very toxic medicines. And in order to protect themselves from side effects, the patients just didn’t take those medicines, they just refused. Then adherence rates came down, and if you don’t have an adherence to treatment of, say 90% of all dosages, then you risk having resistance.”
Resistance, in turn, meant that the HIV/AIDS programmes had to fall back on second- or third-line therapies using patented products, which cost more and meant that fewer patients could be treated. “In the programmes they noticed that they really had to take the adverse reactions seriously, because it was the only way they could maintain their patients on the first-line treatment,” Mr Olsson said.
“I think we have by now managed to explain that pharmacovigilance is part of public health, and we are offering facilities for public health programmes that they don’t have themselves,” he said, adding: “I’ve had a lot of experience of public health programmes and pharmacovigilance coming together. Once they come together and they see what they can do for each other, sweet music occurs.”
Learn more about the development of global pharmacovigilance over the past decades in the full original article in Uppsala Reports.