How to Track Post-Marketing Studies for Drug Safety

When a new drug hits the market, the work isn’t done. In fact, the real test of safety begins after approval. Pre-approval clinical trials involve a few thousand patients under tightly controlled conditions. They rarely include older adults, pregnant women, or people taking multiple medications. That’s where post-marketing surveillance comes in - the ongoing, real-world monitoring of how drugs behave once millions of people start using them.

Tracking these studies isn’t optional. It’s a legal requirement for drug manufacturers and a critical public health function. Missed signals can mean missed dangers. The FDA’s own data shows that 63% of safety actions - like updated warnings or restricted use - are triggered by reports from doctors, patients, and pharmacists after the drug is already out there. So if you’re responsible for managing drug safety, whether you work for a pharmaceutical company, a regulatory body, or a hospital pharmacy, knowing how to track these studies isn’t just helpful - it’s essential.

What Exactly Are Post-Marketing Studies?

Post-marketing studies, also called Phase IV studies, are not optional experiments. They’re mandated by regulators like the FDA and EMA when a drug’s initial data leaves gaps. These studies fall into three main types:

• Observational studies - tracking what happens in real life. For example, researchers might follow 10,000 patients on a new diabetes drug for five years to see if heart failure rates increase.
• Interventional studies - where patients are assigned to specific treatment arms, often to compare long-term outcomes against existing drugs.
• Database studies - analyzing existing electronic health records, insurance claims, or pharmacy databases to find patterns. These can reveal rare side effects that only show up in large populations.

Each study has a deadline. The FDA typically requires completion within three years. But according to the National Academies of Sciences, 72% of these studies run late - often by years. Why? Patient recruitment is slow. Data from different hospitals doesn’t talk to each other. And many companies don’t have the systems in place to track deadlines, milestones, or data quality.

The Core Systems Behind Drug Safety Tracking

Two major systems handle the bulk of safety data in the U.S.: FAERS and Sentinel.

FAERS (FDA Adverse Event Reporting System) is the oldest and most widely used tool. It’s a database with over 30 million reports from healthcare providers, patients, and drug companies. Anyone can submit a report - a nurse noticing unusual bleeding, a patient reporting dizziness, a pharmacist spotting a pattern. These reports are reviewed by teams of scientists who look for signals: unexpected side effects, clusters of reactions, or reactions that happen more often than expected.

But FAERS has limits. It’s passive. It relies on people reporting. Many events go unreported. And it doesn’t tell you if the reaction was caused by the drug or something else - like a patient’s other meds or underlying illness.

That’s where Sentinel comes in. This is an active surveillance system. It pulls data from insurance claims and electronic health records from over 300 million Americans. It can answer questions FAERS can’t: Did patients on this drug have more kidney injuries than those on a similar drug? Did they visit the ER more often? Were they hospitalized? Sentinel can even track lab values, vital signs, and diagnoses over time.

But even Sentinel has gaps. Dr. Janet Woodcock, former head of FDA’s drug division, pointed out that insurance claims often lack clinical details. If a patient has a seizure, did they have a brain tumor? Were they taking a new antibiotic? Without that context, signals can be misleading.

How to Set Up a Tracking System

Companies that manage multiple drugs need a centralized system. Here’s how to build one:

1. Inventory all mandated studies - List every study required by regulators. Include the deadline, the sponsor, the study type, and the regulatory authority (FDA, EMA, etc.). Use a spreadsheet at first, then upgrade to a dedicated pharmacovigilance platform.
2. Assign ownership - Every study needs a lead. That person tracks progress, flags delays, and communicates with investigators. Best practice: One pharmacovigilance specialist for every $500 million in annual sales of the product.
3. Set automated alerts - Use software that sends reminders 90, 60, and 30 days before deadlines. Also set alerts for data milestones: 25% enrollment, 50% data cleaning, final analysis.
4. Integrate data sources - Connect your tracking system to FAERS, Sentinel, and internal safety databases. If a new safety signal pops up in FAERS, your system should auto-flag related studies and pause enrollment if needed.
5. Measure performance - Track the Post-Marketing Study Timeliness Index (PMSTI): the percentage of studies completed on time. Aim for above 85%. If you’re below 70%, you’re at risk of regulatory action.

One company reduced delays by 40% in two years just by implementing automated alerts and assigning clear ownership. They didn’t hire more staff. They just made the process visible.

Common Pitfalls and How to Avoid Them

Many teams fail not because they lack resources, but because they misunderstand the data.

• Mistake: Treating FAERS as a definitive source. Fix: Use FAERS to generate hypotheses, not conclusions. Always cross-check with Sentinel or published literature.
• Mistake: Waiting for regulators to ask for updates. Fix: Submit interim reports quarterly, even if not required. It builds trust and gives you early warning.
• Mistake: Ignoring international data. Fix: Monitor EudraVigilance (EU) and Canada Vigilance Program. A side effect seen in 100 patients in Canada might be invisible in the U.S. due to lower usage.
• Mistake: Assuming the study design is set in stone. Fix: Be ready to adapt. If new safety data emerges, you may need to change your inclusion criteria or add a new endpoint.

Also, don’t underestimate the power of plain text. Many safety signals come from patient reports written in their own words. A simple phrase like “I felt like I was going to pass out after the third pill” can be more telling than a coded lab result. Train your team to read these reports carefully - not just scan for keywords.

What’s Changing in 2025-2026

The field is moving fast. Here’s what’s next:

• Sentinel Common Data Model Plus (SCDM+) - Launching in 2024, this will add genomic data to the mix. If a patient has a rare genetic variant that increases drug toxicity, the system will flag it.
• EudraVigilance AI - The EU’s new system, launching in 2025, will use machine learning to detect signals 30% faster than current methods.
• LLMs in pharmacovigilance - Early pilots show AI can pull safety signals from unstructured EHR notes with 42% more accuracy. But false positives are still 23% higher than human review - so AI is a tool, not a replacement.
• Global data sharing - The WHO is building a network of 100 countries by 2027 to share adverse event data in real time. A reaction seen in Japan might be linked to one in Brazil within hours.

These tools will make tracking easier - but only if you’re ready to use them. Companies that integrate AI and global data into their workflows will get ahead. Those that stick to spreadsheets and manual checks will fall behind.

What You Can Do Today

You don’t need a $10 million system to start tracking effectively.

• Start with one drug. List all its post-marketing studies. Set up a simple calendar with deadlines.
• Sign up for FDA’s Drug Safety Communications. They’re free and updated weekly.
• Check FAERS data monthly. Look for spikes in reports related to your drug.
• Train your team to read narrative reports - not just coded fields.
• Connect with your regional pharmacovigilance center. Many offer free training and data-sharing tools.

Drug safety isn’t about perfection. It’s about awareness. The goal isn’t to catch every single side effect - it’s to catch the ones that could kill someone before it’s too late.