How do we know the long-term effects of new drugs?


When a new cure, treatment, vaccine, etc. comes out after x months or years of testing how do scientists know the effects of the drug longer into the future than the current testing? If a drug has been safe for the past 12 months of testing how do they know it doesn’t kill/harm you at 13 months? Obviously, it has to be released to the public at some point, but how do they make that decision?

In: Biology

That’s why they call public release phase 4. We won’t know, so it gets tested on the open market and the outcomes of people using the drug are continuously monitored so that if it ends up being harmful, the drug gets pulled.

They don’t always know what long term effects of chronic treatments are. But for short term treatments (vaccines provide long term protection, but the actual bits of the vaccine are cleared over a relatively short period), once the active ingredient(s) has been cleared by the body and no lingering effects are reported, it’s generally considered safe. It’s unlikely for a drug to be taken, cleared, show no issues for weeks/months/years afterwards, then suddenly cause problems.

Chronic treatments generally either need more long-term data or need to show a significant benefit to the patient in terms of survival or quality of life improvement over the medium term to be accepted.

We do long term clinical trials. That’s part of the reason why pharmaceuticals take so long to clear in the US and why research and development of these drugs are so expensive. Participants of drug trials are often followed for life; one of the ethical dilemmas that the COVID-19 vaccine trials brought up was many participants were given placebos, but to know if there are any long term effects from the vaccine they cannot be vaccinated. They probably all participated in the trial to be vaccinated early but the people who run the trials must decide what’s more important: continuing a study to see if there are long term side effects of the vaccine or vaccinating the people who risked their lives so we’d have a vaccine for COVID-19