Second-Line TB Drugs

When dealing with second-line TB drugs, medications used after first‑line therapy fails, especially for resistant tuberculosis. Also called reserve anti‑TB agents, they are critical for patients with MDR‑TB, tuberculosis resistant to at least isoniazid and rifampicin or XDR‑TB, forms that remain resistant after exposure to fluoroquinolones and injectable agents. The goal of these drugs is to kill stubborn bacteria that first‑line pills miss. Second-line TB drugs often belong to groups like fluoroquinolones, injectable agents, and newer oral agents such as bedaquiline and delamanid. Fluoroquinolones, for example, fluoroquinolones, a class that includes levofloxacin and moxifloxacin, boost bacterial killing by targeting DNA gyrase. Injectable agents such as amikacin and kanamycin provide a different mechanism by disrupting protein synthesis. Together, these classes form the backbone of a multidrug regimen that prevents further resistance, shortens treatment time, and improves cure rates.

How the drugs fit together and why they matter

Choosing the right combination is like building a puzzle; each piece must fit with the others to block the pathogen from finding a loophole. Clinical guidelines recommend at least four effective drugs, including one fluoroquinolone and one injectable, plus newer oral agents when available. This approach mirrors the comparison style you’ll see in our article collection: we break down efficacy, side‑effect profiles, dosing schedules, and cost for each option. For instance, levofloxacin offers once‑daily dosing and a relatively mild safety record, while moxifloxacin provides stronger activity against certain resistant strains but may raise cardiac concerns. Injectable agents, on the other hand, usually require daily injections, can cause hearing loss, and demand careful monitoring—details we explore in depth in the relevant posts.

Beyond efficacy, resistance patterns drive drug selection. If a patient’s isolate shows resistance to fluoroquinolones, clinicians shift to newer agents like bedaquiline, which targets the mycobacterial ATP synthase. Delamanid works by blocking mycolic acid synthesis, offering an oral alternative when injectables are not feasible. Both drugs have transformed the outlook for XDR‑TB, but they come with monitoring needs such as QT‑interval checks and liver‑function tests. Our guides compare these monitoring requirements side by side, so you can weigh the trade‑offs.

Cost is another real‑world factor. While first‑line drugs are often subsidized, many second‑line agents carry premium price tags, especially newer oral drugs. We’ve compiled price‑comparison tables and cost‑saving tips in the articles below, helping patients and providers navigate budgeting challenges without compromising care.

Finally, patient adherence hinges on regimen simplicity. A once‑daily oral bedaquiline‑plus‑linezolid regimen can be far easier to stick to than a daily injection schedule. The articles in this collection walk you through practical strategies to improve adherence, from side‑effect management to counseling techniques.

Now that you understand the core concepts, drug classes, and real‑world considerations, dive into the detailed posts below. You’ll find side‑by‑side comparisons, safety checklists, dosing charts, and cost guides that turn complex treatment decisions into clear, actionable steps.