DNA, Folate & Others

Fluoroquinolones: Powerful, Convenient — and Quietly Risky

Imagine a broad, potent antibiotic that works brilliantly as a simple oral pill — and can also, rarely, snap a patient's Achilles tendon, tear a major artery, or trigger a seizure. Fluoroquinolones are so useful that they were once handed out for almost anything, and so quietly dangerous that regulators now plaster them with their strongest warnings. Learning where their power ends and their harm begins is the whole point.

Sulfonamides & Trimethoprim: Starving Bacteria of Folate

Bacteria have to build their own folate from scratch; we simply eat ours. That single difference is a perfect weakness to exploit — and two drugs that block the folate pathway at two different steps combine into one of the most elegant antibiotics we have. But the same drug that saves lives in immunocompromised patients can also peel the skin off in a rare, terrifying reaction.

Metronidazole, Nitrofurantoin & Urinary Agents

One antibiotic is so intolerant of alcohol that a single drink can leave you flushed, vomiting, and pounding — a drug that only 'switches on' inside the oxygen-starved bacteria and parasites it kills. Another works only in one place in the body: the bladder. These specialist drugs teach a beautiful lesson in how WHERE and WHEN a drug becomes active decides exactly what it can treat.