Moxifloxacin 400mg

Antibiotic; Respiratory Fluoroquinolone

“ALERT: US Boxed Warning

Serious adverse reactions:

Fluoroquinolones have been associated with disabling and potentially irreversible serious adverse reactions that have occurred together, including tendinitis and tendon rupture, peripheral neuropathy, and CNS effects. Discontinue moxifloxacin immediately and avoid the use of fluoroquinolones in patients who experience any of these serious adverse reactions. Because fluoroquinolones have been associated with serious adverse reactions, reserve moxifloxacin for use in patients who have no alternative treatment options for the following indications: acute bacterial sinusitis and acute bacterial exacerbation of chronic bronchitis.

Myasthenia gravis:

Fluoroquinolones may exacerbate muscle weakness in persons with myasthenia gravis. Avoid moxifloxacin in patients with known history of myasthenia gravis.”

CSA NA – FDA Approved – REMS (N) – Can Ship

Inhibits DNA gyrase and topoisomerase IV in susceptible bacteria which are important in protein synthesis.  Blocking these inhibits relaxation of supercoiled DNA so it cannot be used for protein synthesis and promotes the breakage of double stranded DNA eventually causing cell death.  Humans do not have DNA gyrase which makes it an ideal target for antibiotics.

Moxifloxacin is used on or off label for various infections depending on your common local bacterial strains for various infections and based on local resistance patterns.  Not all antibiotics work for all infections and efficacy can vary from area to area and vary with time.  It is common in North America for various respiratory infection hence the classification of respiratory fluoroquinolone.  

Before starting Moxifloxacin make sure your physician is aware of any allergies or medications you currently take, if you have cardiovascular disease, kidney disease, liver disease, diabetes, rheumatoid arthritis, myasthenia gravis, or if you are pregnant, or breastfeeding.

400mg once a day

How to Take: Follow instructions provided by physician/pharmacy label, take consistently at same times each day unless otherwise directed, with or without food, store at room temperature

You Need to Avoid: Avoid use of antacids, multivitamins or any other sources of magnesium, aluminum, iron, or zinc.  If they are required, then take ciprofloxacin 4 hours before or 8 hours after these products as they will decrease absorption.

Ciprofloxacin is generally very well tolerated except in children and should be avoided in them due to risk of musculoskeletal effects unless no other options exist.  Rates of side effects in adults are quite low (under 10% risk for all) however their use needs to be limited to rare but serious irreversible side effects that may occur. 

Moxifloxacin can cause QT prolongation which can result in severe cardiac arrythmia, increased risk of aortic aneurism/dissection, irreversible tendonitis, tendon rupture, peripheral neuropathy, psychiatric symptoms (delirium, agitation, nervousness, hallucinations, paranoia) and central nervous system effects such as seizure and increased intracranial pressure.  It is also broad spectrum (kills many kinds of bacteria) which means it can increase risk of opportunistic superinfection such as C. difficile associated diarrhea.   It is important to note that these reactions are all very rare but due to their severity caution in prescribing is recommended.  

1. Why would my physician prescribe a medication with such serious side effects?
   Bacterial resistance is becoming more of an issue and not all antibiotics work for all bacteria.  Certain antibiotics concentrate in different parts of the body which can also affect which ones work in which situations.  Your physician takes the most recent clinical guidelines and follows local resistance patterns to make evidence-based decisions that are reviewed and agreed upon by the medical community as to what agents should be used in which types of infections.  Your current medications, your allergies, age, cost of medication, side effects you experience from various antibiotics and many other factors will further complicate or limit which medications are appropriate.  This decision was not made lightly, however if you are concerned, ask your physician to clarify why they made their choice of antibiotic and they can let you know why this was the best option for this scenario.
2. What do I do if side effects are intolerable?
   If side effects are causing a lot of distress speak to your physician as soon as possible to discuss options.