Is Levofloxacin (Levaquin) more toxic than other quinolones?
Levofloxacin, a modified form of ofloxacin, is one of the most potent quinolones (about twice as potent as ofloxacin). Therefore, does levofloxacin exhibit a higher level of toxicity and rate of adverse reactions when compared to other fluoroquinolones?
According to various research sources, this indeed appears to be the case. There is a startling difference in number of adverse reaction reports between Levaquin and Cipro, the top 2 most prescribed quinolones, in medications.com itself. Looking at http://www.medications.com/drugs/ Levaquin has over 2000 reports of side effects, while Cipro only has 73.
Moreover, according to a research study by L Mandell, MD FRCPC and G Tillotson, MSc FRSM, Levofloxacin may have a higher rate of side effects compared to other fluoroquinolones of the third generation. See the table below (note that the information is directly from the drug companies and the true rates of side effects are much higher):
Comparison of adverse drug reactions associated with some approved fluoroquinolones (%)
| Reaction |
Levofloxacin |
|
Gatifloxacin |
|
|
Moxifloxacin |
|
| Reference |
PI |
50* |
51 |
31 |
30 |
51 |
52 |
| No patients |
NR |
2252 |
1655 |
15,625 |
6170 |
6500 |
18,409 |
| Nausea |
7.1 |
9 |
2.8 |
4 |
8 |
0.3 |
5.7 |
| Diarrhea |
5.6 |
4 |
1.7 |
1.4 |
6 |
0.9 |
2.4 |
| Headache |
6.4 |
4 |
0.5 |
0.9 |
2 |
0.1 |
<2 |
| Vomiting |
2.2 |
2 |
0.6 |
0.7 |
2 |
0.2 |
<1 |
| Vaginitis |
1.6 |
5 |
<1 |
<1 |
<1 |
NI |
<1 |
| Dizziness |
2.9 |
3 |
1.3 |
NR |
3 |
0.3 |
2.3 |
| Taste perversion |
1.0 |
2 |
0.8 |
0.5 |
<1 |
NR |
<1 |
| Discontinuations |
3.4 |
3.2 |
NR |
3.1 |
NR |
NR |
NR |
This hypothesis also correlates with the speculation of Jay S Cohen, MD, that there may be a "previously unrecognized tendency toward greater neurotoxicity with levofloxacin." (http://fqvictims.org/fqvictims/News/neuropathy/Neuropathy.pdf)
Another source from fluoroquinolones.org suggests that Levofloxacin is one of the most potent quinolones in terms of side effects:
According to T Boomer, a fluoroquinolone researcher, "500 mg of levaquin tends to cause as much damage as 1000 mg of ciprofloxacin."
In conclusion, levofloxacin may exhibit higher rates of toxicity when compared with older quinolone agents such as ciprofloxacin, and with newer quinolones including moxifloxacin. This observation could explain the abnormally high incidence of adverse reaction reports with Levaquin.
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Comments
this study useless
this study is worthless. reactions depend on what dosage a patient was prescribed and how long
patient took it. these reactions listed here are not the common serious reactions involving tendons,
nerves, neuromuscular system, endocrine system, etc. This study makes it appear these reactions]
are temporary... rather than permanent and disabling.
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