June 24th, 2012

ID Learning Unit — Choosing a Quinolone

We love quinolones on medical services, and it’s easy to understand why. Advantages:

  • Ideal spectrum for several common infections, including community-acquired pneumonia, UTIs, and more complex infections when combined with other drugs
  • Great oral absorption
  • Few drug-drug interactions
  • Once- or twice-daily dosing
  • Generally well tolerated
  • Reasonable cost

But how do you choose between them? Below, in a concise and admittedly somewhat oversimplified table, is all the medical intern/resident/hospitalist needs to know about our friends the quinolones:

Drug Activity vs gram – rods (rank) Activity vs gram + cocci (rank) Activity vs Anaerobes (rank) Metabolism Comments/Fun facts
Ciprofloxacin 1 3 3 Kidney Don’t use for Strep pneumo; no association with increased cardiac death in recent study (unlike levo, azithro)
Levofloxacin 2 2 3 Kidney Active (left) enantomer of ofloxacin – hence its name. How cool is that?
Moxifloxacin 3 1 1 Liver Not active vs. Pseudomonas; generally the preferred quinolone for mycobacterial infections

But it’s not all sunshine and happiness with these drugs. Problems:

  • That nasty tendon issue
  • Can make people (especially the elderly) kind of crazy – “like 5 cups of Starbucks, and not in a good way”, was one patient’s memorable description
  • Photosensitivity
  • QT prolongation
  • Oral absorption blocked by concomitant iron, magnesium, calcium, aluminum, and probably also Krugerrands if you happen to be eating them
  • C diff risk, something we really didn’t see until the emergence of the more virulent strain
  • Ever rising rates of resistance with gram negative rods, Staph aureus

Bottom line? These are great antibiotics – but they are not interchangeable, and not 100% safe.

Extra credit:  Can you name the five quinolones that have been pulled by the FDA for safety reasons? Double points if you get the reason they are no longer available, triple points if you also get the brand names and match them to the actual drugs.

Here’s a hint to get you started.

9 Responses to “ID Learning Unit — Choosing a Quinolone”

  1. john c. parker says:

    thanks for your id learnung units!

  2. D. Branam says:

    sparfloxacin – Zagam – QT prolongation
    gatifloxacin – Tequin – dysglycemias
    trovafloxacin – Trovan* – hepatotoxicity
    temafloxacin – Omniflox – hepatoxicity
    grepafloxacin – Raxar – Qt prolongation

    *My understanding is Trovan is still available under compassionate use criteria for MDROs.

    • Paul Sax says:

      D —

      Outstanding! I think you’re right about trovafloxacin.

      I believe temafloxacin was pulled due to allergic reactions and hemolysis — and even was the topic of a TV special.

      Sparfloxacin also had an incredibly high incidence of phototoxicity.


  3. Eduardo Pozzobon says:

    What about gemifloxacin (factive)? How it ranks among quinolones?

    • Paul Sax says:

      Gemifloxacin is rarely used in the USA since it so often can cause a rash. Also, it’s only approved for “mild to moderate” respiratory infections, making it less desirable than levo or moxi.


  4. Loretta S says:

    Why are both levo- and cipro- ranked number 3 for anaerobe activity? Is there no second-best?

    • Paul Sax says:

      Loretta, good pick-up. I couldn’t really find a good reference that would rank these two, so I made them “Tied”. Paul

  5. GaryLA says:

    Sadly I am among the elderly who were severely adversely affected by attempting to start taking Levaquin last year with horrible extremely unpleasant frightening unbearable mental paralysis-depression-stoneness which was a very horrible brief short-term nightmare and had to return to “bactrim” for fighting recurring UTIs.

  6. Anonydoc says:

    Now this is a VERY late reply.
    Ciprofloxacin does have some hepatic metabolism, and strong interactions are possible through the CYP system. main mechanism of excretion is renal, indeed.

    am i wrong on these pharmakokinetic stats?

HIV Information: Author Paul Sax, M.D.

Paul E. Sax, MD

Contributing Editor

NEJM Journal Watch
Infectious Diseases

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