<p>Not to hijack the thread but the PCP could have been fully justified in prescribing Zithromax. Avelox is not an innocous medication and it’s use should be limited to appropriate medical situations:</p>
<p>Adverse effectsSee also: Adverse effects of fluoroquinolones
The serious adverse effects that may occur as a result of moxifloxacin therapy include irreversible peripheral neuropathy, spontaneous tendon rupture and tendonitis,[54] acute liver failure or serious liver injury, QTc prolongation/torsades de pointes, toxic epidermal necrolysis (TEN), and clostridium difficile-associated disease (CDAD),[55] as well as photosensitivity/phototoxicity reactions.[56] Hepatitis, pseudomembranous colitis, psychotic reactions and Stevens-Johnson syndrome have also been associated with moxifloxacin therapy.[57]</p>
<p>There has been a number of regulatory actions taken as a result of such adverse reactions, which include published warnings,[58] the issuance of numerous “Dear Doctor Letters”,[4][6][7][59] the restrictions regarding the use of moxifloxacin instituted by the European agency’s Committee for Medicinal Products for Human Use (CHMP),[10] as well as the recent addition of Black Box Warnings.[60] On March 22, 2010 Health Canada issued a notice to health care professionals and Canadians regarding the recent changes to the labeling information for Avelox (moxifloxacin). The 2010 Canadian updated labeling now includes information regarding the risk of severe liver injury during moxifloxacin therapy.[61]</p>
<p>These serious events may occur with therapeutic or with acute overdose. Such adverse reactions may manifest during, as well as after moxifloxacin therapy.[62]</p>
<p>Most recently, the German regulatory authorities placed additional restrictions on the use of oral moxifloxacin in patients with acute bacterial sinusitis (ABS), acute exacerbation of chronic bronchitis (AECB), and community-acquired pneumonia (CAP) stating that in case of these diseases moxifloxacin should only be prescribed when other antibiotics that have been initially recommended for treatment cannot be used or have failed. Additional notice was given that rhabdomyolysis, the exacerbation of symptoms of myasthenia gravis and the risk of cardiac arrhythmia in women and older patients, was associated with moxifloxacin.[7] Currently the German regulatory authorities are investigating the association of severe and life threatening QTc prolongation/torsades de pointes with moxifloxacin therapy, which the FDA had raised serious concerns about during the initial drug approval process back in 1999.[63][64][65]</p>
<p>Serious visual complications have also been reported to occur with ophthalmic fluoroquinolone therapy, which may also occur with Vigamox, especially corneal perforation, but also evisceration and enucleation. Corneal perforation occurred most commonly in elderly patients with deep ulcers. This increased incidents of corneal perforation may be due to fluoroquinolones’ causing alterations in stromal collagen, leading to a reduction in tectonic strength.[66][67]</p>
<p>[edit] InteractionsAntacids containing aluminium or magnesium ions inhibit the absorption of moxifloxacin. Drugs that prolong the QT interval (e.g., pimozide) may have an additive effect on QT prolongation and lead to increased risk of ventricular arrhythmias. The INR (International Normalised Ratio) may be increased or decreased in patients treated with warfarin. Moxifloxacin has been shown in a number of case reports to interact with warfarin.[68] The exact mechanism for the warfarin-quinolone drug interaction is unknown.[69] A precautionary measure would be to monitor the INR more closely and, if necessary, adjust the anticoagulant dose as necessary. Moxifloxacin does not appear to inhibit theophylline metabolism.[70] However, caution may be warranted when using theophylline with all of the fluoroquinolones, including moxifloxacin. Drug Interaction Facts notes that some fluoroquinolones, especially ciprofloxacin, enoxacin, and norfloxacin, interact with theophylline</p>
<p>There are only two listed contraindications found within the 2008 package insert:</p>
<p>“Nonsteroidal anti-inflammatory drugs (NSAIDs): Although not observed with moxifloxacin in preclinical and clinical trials, the concomitant administration of a nonsteroidal anti-inflammatory drug with a fluoroquinolone may increase the risks of CNS stimulation and convulsions.” [46]
“Moxifloxacin is contraindicated in persons with a history of hypersensitivity to moxifloxacin, any member of the quinolone class of antimicrobial agents, or any of the product components.”[46]
Though not stated as such within the package insert, ziprasidone is also considered to be contraindicated, as it may have the potential to prolong QT interval. Moxifloxacin should also be avoided in patients with uncorrected hypokalemia, or concurrent administration of other medications known to prolong the QT interval (antipsychotics and tricyclic antidepressants).[47]</p>
<p>Moxifloxacin should be used with caution in patients suffering from diabetes, as glucose regulation may be significantly altered.[47]</p>
<p>Moxifloxacin is also considered to be contraindicated within the pediatric population, pregnancy, nursing mothers, patients with a history of tendon disorder, patients with documented QT prolongation,[7] and patients with epilepsy or other seizure disorders. Coadministration of moxifloxacin with other drugs that also prolong the QT interval or induce bradycardia (e.g., beta-blockers, amiodarone) should be avoided. Careful consideration should be given in the use of moxifloxacin in patients with cardiovascular disease, including those with conduction abnormalities.[47]</p>
<p>Recently (2008), Bayer issued a Europrean Dear Doctor Letter concerning moxifloxacin-associated liver damage, and, as such, the use of moxifloxacin would now be considered contraindicated in patients with impaired liver function</p>
<p>I do not know the comorbid conditions of your patient, but a 70 year old with diabetes most likely has coronary artery disease, is taking a NSAID, may be on coumadin etc. Also, Avelox is substantially more expensive than Zithromax. </p>
<p>My main point is there are many variables to consider when choosing any medication and simply choosing the most potent antibiotic (esp initially) may not be in the best interest of your patient and I suspect your preceptor knew as much. Not trying to bash but just trying to help point out a few other things to consider. By the way, my son is also planning on a career in academic medicine for many of the reasons you have delineated.</p>