The Story of Gatifloxacin (Tequin)
Gatifloxacin, marketed as Tequin, was a fourth-generation fluoroquinolone antibiotic approved by the FDA in December 1999. It was used to treat various bacterial infections, including respiratory, sinus, and urinary tract infections. Its broad spectrum of activity made it effective against many bacteria by inhibiting enzymes needed for their DNA replication. However, post-marketing reports revealed significant safety concerns.
The Primary Reason for Withdrawal: Severe Dysglycemia
The main reason systemic gatifloxacin was withdrawn from the market in the U.S. and Canada was its strong link to severe, sometimes fatal, blood sugar fluctuations, known as dysglycemia.
- Hyperglycemia (High Blood Sugar): A study in The New England Journal of Medicine showed older adults taking gatifloxacin had a nearly 17 times higher chance of hospitalization for hyperglycemia compared to those on other broad-spectrum antibiotics. This risk affected patients with and without diabetes and could lead to serious complications like hyperosmolar nonketotic coma.
- Hypoglycemia (Low Blood Sugar): The same study found gatifloxacin users were over 4 times more likely to be hospitalized for hypoglycemia. These episodes could be severe, even fatal, especially in older patients and those on diabetes medications.
Gatifloxacin is thought to cause these issues by affecting the pancreatic beta cells, which produce insulin. It may overstimulate insulin release, leading to hypoglycemia. The cause of hyperglycemia is less clear but might involve pancreatic damage.
Timeline of Market Withdrawal
The drug's time on the market was relatively short:
- December 1999: FDA approves Gatifloxacin (Tequin).
- Early 2000s: Reports of severe blood sugar issues emerge.
- February 2006: The manufacturer and FDA add stronger warnings and contraindicate use in diabetics.
- May 1, 2006: Public Citizen requests a ban due to hospitalizations and deaths.
- June 2006: The manufacturer voluntarily withdraws Tequin, citing business reasons.
- September 2008: The FDA confirms Tequin was withdrawn for safety/effectiveness issues, preventing generic versions.
Comparison with Other Fluoroquinolones
Compared to other fluoroquinolones, gatifloxacin had a notably higher risk of dysglycemia.
| Feature | Gatifloxacin | Levofloxacin (Levaquin) | Ciprofloxacin (Cipro) | Moxifloxacin (Avelox) |
|---|---|---|---|---|
| Generation | Fourth | Third | Second | Fourth |
| Primary Spectrum | Broad, good Gram-positive activity | Broad, good Gram-positive activity | Primarily Gram-negative focus | Enhanced Gram-positive & anaerobic activity |
| Key Safety Concern | Severe Dysglycemia | Tendinopathy, CNS effects, slight hypoglycemia risk | Tendinopathy, CNS effects | QT Prolongation, some dysglycemia risk (less than gatifloxacin) |
| US Market Status | Withdrawn (Systemic) | Available | Available | Available |
Other fluoroquinolones have a lower risk of hypoglycemia and not the significant hyperglycemia risk seen with gatifloxacin.
Other Fluoroquinolone Class Risks
Gatifloxacin also shared risks common to all fluoroquinolones, which have FDA black box warnings. These include tendon issues, nerve damage (peripheral neuropathy), CNS problems, and risks to the aorta.
Conclusion and Current Status
Gatifloxacin's withdrawal highlights the importance of monitoring drug safety after approval. Despite initial promise, its severe dysglycemia risk was unacceptable, especially with safer options available. The ban on systemic gatifloxacin resulted directly from its potential for dangerous blood sugar changes.
Topical ophthalmic (eye drop) gatifloxacin is still available. This is because it is minimally absorbed into the bloodstream, avoiding the systemic dysglycemia risk. Systemic forms might still be used in some countries, but it is generally discouraged where safer alternatives exist.
For more information on the history of this drug's withdrawal, consult the official notice in the Federal Register.
