How to Track Post-Marketing Studies for Drug Safety

10 Nov 2025

by Kendrick Monaghan
13 Comments

Why Post-Marketing Drug Safety Tracking Matters

Drugs get approved based on clinical trials with a few thousand patients-often healthy adults, mostly under 65, and rarely pregnant women or people with multiple chronic conditions. But once a medicine hits the market, millions of people take it. Some will have side effects no one saw in trials. That’s where post-marketing surveillance comes in. It’s not optional. It’s mandatory. And if you’re responsible for tracking these studies, missing a signal could mean lives at risk.

The FDA’s Adverse Event Reporting System (FAERS) has over 30 million reports. That’s not just data-it’s early warnings. One report might be noise. But when 50 people report the same rare heart rhythm issue after taking a new diabetes drug, that’s a signal. And if you don’t catch it, regulators step in. Label changes. Black box warnings. Even withdrawals. You need systems that don’t just collect data but actively hunt for patterns.

Key Systems Used to Track Drug Safety After Approval

There’s no single tool. You need multiple streams working together. The big ones:

FAERS (FDA Adverse Event Reporting System): The backbone. Anyone-doctors, patients, pharmacists, or manufacturers-can submit a report. It’s voluntary, so underreporting is common. But it’s still the fastest way to spot unusual clusters. In 2022, 63% of safety actions started here.
Sentinel System: This isn’t just reports. It’s real-world data from insurance claims and electronic health records of over 300 million Americans. It shows what’s actually happening in clinics, not just what’s written in a form. Sentinel found that 28% of serious reactions in elderly patients were invisible in trials because older adults were barely included.
Post-Marketing Clinical Studies: Sometimes regulators require companies to run new studies after approval. These aren’t optional. They’re legally binding. For example, a new antidepressant might need a 5-year study tracking suicide risk in teens. If you miss deadlines, you risk fines or losing your license.
Yellow Card (UK) and Canada Vigilance: Even if you’re not in the U.S., global data matters. A side effect seen in Canada might show up in FAERS months later. Cross-border monitoring isn’t nice to have-it’s necessary.

How to Set Up a Tracking System That Actually Works

Tracking isn’t about storing reports. It’s about acting on them. Here’s how to build a system that doesn’t fall behind:

Centralize all data. Don’t let reports sit in spreadsheets, emails, or disconnected databases. Use a pharmacovigilance database that pulls in FAERS, Sentinel alerts, literature reviews, and internal study data. Make sure it’s searchable by drug, reaction, patient age, and date.
Set automated alerts. Configure rules like: “Alert me if 5 or more reports of liver injury appear for Drug X within 30 days.” Don’t wait for monthly reviews. Real-time flags save time-and lives.
Assign ownership. Every study, every signal, every regulatory request needs one person responsible. Not a team. One person. If it slips, you know who to ask.
Track deadlines like a project manager. The FDA requires most post-marketing studies to finish in 3 years. But the average takes 5.3. Why? Poor planning. Build a timeline with milestones: IRB approval, patient enrollment, data collection, analysis, report submission. Use Gantt charts. Set reminders. Miss a deadline, and you’re on the regulator’s radar.
Use standardized metrics. Track your Post-Marketing Study Timeliness Index (PMSTI): % of studies completed on time. Aim for 90%. If you’re at 60%, you’ve got a process problem, not a staffing problem.

Scientist at a colorful control console surrounded by deadline clocks and safety alert icons

What Happens When a Safety Signal Is Found

Finding a problem is only step one. What you do next matters more.

Once a signal is confirmed through multiple data sources, the FDA’s Office of Surveillance and Epidemiology steps in. They look at:

How many people are affected?
How severe are the outcomes?
Is there a clear link to the drug?
Can the benefit still outweigh the risk?

Then they decide:

Label update (87% of actions): Add a warning about liver damage, drug interactions, or pregnancy risks.
Dear Doctor letter (9%): A direct notice to prescribers telling them to avoid the drug in certain patients.
REMS modification (3%): Tighten restrictions-like requiring special training before prescribing or limiting distribution to certified pharmacies.
Market withdrawal (<1%): Rare, but happens. Think Vioxx, fenfluramine, or the diabetes drug troglitazone.

In 2020-2022 alone, the FDA issued 147 Drug Safety Communications affecting 112 drugs. If you’re tracking safety, you need to subscribe to these. Set up email alerts. Check the FDA’s website weekly.

Biggest Challenges-and How to Beat Them

Even the best systems struggle. Here’s what goes wrong-and how to fix it:

Delayed studies: 72% of FDA-mandated studies run late. Why? Poor patient recruitment. Solution: Partner with clinics early. Use EHR data to find eligible patients before you even start the study.
Incomplete data: Sentinel can’t see lab results or vital signs from claims data. Solution: Push for direct EHR integration. Work with data partners who can share structured clinical notes.
False signals: AI tools can flag 34% more noise than real risks. Solution: Don’t trust algorithms alone. Use them to prioritize, but always validate with human review. Combine statistical models with clinical judgment.
Global fragmentation: Data doesn’t flow easily between countries. Solution: Join international networks like WHO’s Global Individual Case Safety Report database. Share anonymized data. You’ll catch signals faster.

And don’t underestimate culture. If your team sees pharmacovigilance as a compliance chore, you’ll miss things. Make it part of your company’s safety DNA. Reward teams that find signals early. Celebrate when you prevent harm.

Global map of rainbow ribbons showing international safety signals flowing to a central hub

What’s Coming Next in Drug Safety Tracking

The field is changing fast. Here’s what’s on the horizon:

Sentinel Common Data Model Plus (SCDM+): By 2026, it’ll include genomic data for 50 million patients. That means we’ll soon know if a side effect hits harder in people with a certain gene variant.
EU’s EudraVigilance AI system: Launching in 2025, it’ll use machine learning to auto-detect signals from millions of reports across Europe.
LLMs analyzing EHR notes: Pilot programs show AI can now read doctor’s notes and pull out hidden adverse events. Accuracy jumped 42%. But false positives are still high-so use it as a filter, not a final answer.
Global data sharing: WHO aims to connect 100 countries by 2027. That means a rare reaction in Brazil could trigger a warning in Australia within days.

These aren’t futuristic ideas. They’re happening now. If you’re not preparing for them, you’re already behind.

Final Checklist: Are You Tracking Drug Safety Right?

Before you close your browser, ask yourself:

Do I have a single system pulling in FAERS, Sentinel, and internal study data?
Are automated alerts set up for high-risk drugs or new launches?
Is someone accountable for every post-marketing study deadline?
Do I review FDA Drug Safety Communications weekly?
Have I trained my team to treat safety data as critical-not just paperwork?

If you answered yes to all five, you’re doing better than most. If not, pick one thing to fix this week. Start with the alerts. They’re the easiest win-and the most life-saving.

What is the difference between FAERS and Sentinel?

FAERS collects voluntary reports from doctors, patients, and drug companies. It’s good for spotting rare or unexpected reactions quickly. Sentinel uses real-world data from insurance claims and electronic health records of hundreds of millions of people. It shows patterns in how drugs are used and what happens in real clinics. FAERS is reactive. Sentinel is proactive. Together, they give a full picture.

How often do post-marketing studies get delayed?

About 72% of FDA-mandated post-marketing studies miss their deadlines. The average study takes 5.3 years to complete, even though the requirement is 3 years. The main reasons are slow patient enrollment, lack of access to clinical data, and poor planning. Companies that use distributed data networks and partner with clinics early finish on time more often.

What’s the most common safety action taken after a drug is approved?

Label updates. In 87% of safety actions between 2018 and 2022, the FDA added or strengthened warnings on the drug’s label-like new contraindications, dosage limits, or risks for certain groups. This is the most common way regulators respond without pulling a drug off the market.

Can patients report adverse drug reactions?

Yes. Anyone can report a side effect to FAERS-patients, family members, pharmacists, or caregivers. In fact, patient reports are growing. In 2022, over 20% of FAERS reports came directly from consumers. These often capture unique experiences that doctors miss, like subtle cognitive changes or long-term fatigue. Don’t ignore them.

What’s a REMS and why does it matter?

REMS stands for Risk Evaluation and Mitigation Strategy. It’s a set of special requirements the FDA can impose on a drug if it has serious safety risks. This could mean only certified doctors can prescribe it, patients must enroll in a registry, or the drug can only be dispensed through specific pharmacies. REMS isn’t just paperwork-it’s a safety net. If you’re tracking a drug with a REMS, you must monitor compliance. Failure can lead to enforcement actions.

Are AI tools reliable for detecting drug safety signals?

They’re helpful, but not perfect. AI can analyze millions of reports faster than humans and has improved signal detection accuracy by 42% in pilot tests. But false positives are still 23% higher than traditional methods. AI should be used to prioritize signals, not make final decisions. Always combine AI findings with clinical review and statistical validation.

What People Say

Arpita Shukla
November 10, 2025

I've seen too many companies bury adverse events in PDFs no one reads. Centralizing data isn't optional-it's the bare minimum. If your system still relies on Excel sheets, you're not tracking safety, you're gambling with lives.
Mark Rutkowski
November 11, 2025

You know what's wild? We spend billions on clinical trials that exclude 80% of real-world patients... then act shocked when the drug breaks in the wild. The Sentinel System isn't just a tool-it's a reckoning. The data was always there. We just refused to look.
Ryan Everhart
November 12, 2025

So we have 30 million FAERS reports and still need a person to 'own' every signal? Cool. So we're automating data collection but outsourcing critical thinking to one overworked person who probably hasn't slept since 2021. That's not a system. That's a burnout factory.
David Barry
November 13, 2025

PMSTI at 90%? That's a fantasy. I've worked in three pharma firms. The average is 42%. The FDA doesn't audit timelines until the study is 18 months late. By then, the damage is done and the PR team is drafting the 'we're committed to patient safety' press release. Metrics are for PowerPoint. Real safety is chaos.
Alyssa Lopez
November 15, 2025

USA leads the world in drug safety. No other country has Sentinel. No other country has the resources. Why are we even talking about Yellow Card? If you're not using FAERS as your primary source, you're doing it wrong. America built this system-don't dilute it with foreign noise.
Alex Ramos
November 15, 2025

Automation + ownership = game changer. Seriously. We cut our signal detection time from 90 days to 11 after setting up those rules. Also, if you're not using a proper PV system, get off the internet and call your IT department. You're risking people's lives with spreadsheets. 😅
edgar popa
November 16, 2025

missed deadline? no biggie. just send another email. theyll forgivve you. lol
Eve Miller
November 18, 2025

The notion that 'one person owns' a signal is dangerously irresponsible. Pharmacovigilance is a team function. Assigning singular ownership creates dangerous single points of failure-and frankly, reveals a fundamental misunderstanding of systems thinking. This post is dangerously oversimplified.
Chrisna Bronkhorst
November 18, 2025

90% on-time completion? You're joking right? I've seen studies delayed for 4 years because the CRO couldn't find a single patient. The system is broken. We're collecting data like it's a cult ritual and pretending it's science.
Amie Wilde
November 19, 2025

I read this on my lunch break. Honestly? Most of this is common sense. But the fact that we need a 2000-word guide to not kill people with pills says everything about how broken the system is.
Gary Hattis
November 19, 2025

In South Africa, we don't have Sentinel. We don't even have reliable FAERS access. We rely on hospital logs and word of mouth. If a kid has a seizure after a new antimalarial, we find out three months later when three more kids show up with the same thing. This post reads like a luxury manual for wealthy countries. Global safety isn't a checklist-it's a cry for help.
Esperanza Decor
November 21, 2025

This is the kind of post that makes me want to go back to school and study pharmacovigilance. We're talking about real people here-not data points. Every report is someone's parent, sibling, friend. If we treat this like a spreadsheet game, we've already lost. Let's do better. We owe it to them.
Deepa Lakshminarasimhan
November 22, 2025

FAERS is rigged. The FDA gets paid by Big Pharma. Those 'signals'? They're planted to scare people into buying new drugs. The 'heart rhythm issue' you mentioned? That's the same one they used to pull the last drug. Now they're pushing a 'new and improved' version. Wake up. This isn't safety. It's profit theater.