Post-Market Surveillance: How Drug Safety Is Monitored After Approval

When a drug gets approved, the job isn’t done. Post-market surveillance, the ongoing monitoring of drugs after they’re sold to the public. Also known as pharmacovigilance, it’s how regulators and manufacturers catch problems that didn’t show up in clinical trials—like rare side effects, dangerous interactions, or manufacturing flaws that only appear when thousands of people are using the drug. This isn’t just paperwork. It’s what stops another Vioxx or thalidomide from hurting more people.

Real-world use is messy. People take multiple drugs. They have other health conditions. They might not follow instructions perfectly. That’s why adverse event reporting, the process where patients, doctors, and pharmacists report unexpected side effects is critical. Systems like FDA MedWatch, the U.S. government’s official channel for reporting drug safety issues let anyone—patients included—flag problems. A single report might seem small, but when hundreds pile up, it triggers reviews, label changes, or even recalls. Generic drugs aren’t exempt. In fact, underreporting of side effects from generics is a known gap, which is why recent efforts focus on making reporting easier and more consistent across brands and generics alike.

What you’ll find in this collection isn’t theory. It’s real cases: how a blood thinner overdose leads to internal bleeding, why lithium generics need tight serum level checks, how goldenseal messes with liver enzymes, and why fluoroquinolones can tear tendons. You’ll see how patent games affect drug safety, how counterfeit pills contain fentanyl, and why pill splitting can be dangerous if done wrong. These aren’t isolated incidents—they’re all pieces of the same puzzle: post-market surveillance. It’s not about stopping drugs. It’s about making sure the ones we use are as safe as possible once they’re out in the wild. Below, you’ll find guides, warnings, and practical steps that help you stay safe—and help the system work better.