Chlamydia treatment

[anbuitachi]

So the 3 drugs commonly used for Chlamydia are azithromycin, erythromycin and amoxicillin. [Uptodate]

Why does amoxicillin treat chlamydia?? Uworld said chlamydia lacks peptidoglycan so pencillin type drugs wont work on it..


And why is azithromycin 1 dose, but erythro is 7days when they are both macrolides..??

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[Myxedema]

Short answer: Beta-lactams have another MOC when exerting their effect in Chlamydial infections.

Long answer: (http://aac.asm.org/content/43/9/2311.full) "Penicillins allow conversion of elementary bodies to reticulate bodies but inhibit the multiplication of reticulate bodies and the differentiation of reticulate bodies into infectious elementary bodies, without necessarily exerting a lethal effect on the organism"

Apparently, Chlamydia possess PBPs which allow this type of action.

 

[Phloston]

One oral dose of azithromycin is used first. Then we go to one-week of tetracyclines if the infection is refractory.

 

[anbuitachi]

Thanks!.

And for treatment, I meant alternatives to azithromycin. My book says erythromycin can be used as an alternative to azithromycin, but requires at least 7 days as opposed to 1 dose azithro. Just not sure why such a big difference when they are both macrolides

 

[Myxedema]

CDC's STD Treatment Guidelines should be taken as a basis here: http://www.cdc.gov/std/treatment/2010/chlamydial-infections.htm

- Azithromycin and doxycycline are first-line treatments
- Alternatives are erythromycin, levofloxacin and ofloxacin

There are also alternative regimens for pregnancy, neonatal and pediatric usage.

 

[Transposony]

but requires at least 7 days as opposed to 1 dose azithro. Just not sure why such a big difference when they are both macrolides

It's about half life.
I think you need to brush up your Pharma basics (dynamics,kinetics,volume of distribution etc).

 

[Phloston]

Thanks!.

And for treatment, I meant alternatives to azithromycin. My book says erythromycin can be used as an alternative to azithromycin, but requires at least 7 days as opposed to 1 dose azithro. Just not sure why such a big difference when they are both macrolides

It's about half life.
I think you need to brush up your Pharma basics (dynamics,kinetics,volume of distribution etc).

There are only two things, metabolism-wise, regarding those two drugs that are important for Step1:

1) Azithromycin doesn't inhibit P-450, whereas erythromycin does.

2) Erythromycin is the only macrolide notably eliminated through bile (that's why it can cause cholestatic hepatitis, as per FA). The others are renally excreted.

 

[dozer1]

Can someone please explain the pathophysiology behind this line:

"Diphtheria toxin is carried by a phage, so only lysogenic organisms cause systemic disease" this is from micro flash cards.

Does this mean you get infected with any virus that caries the phage/DNA for the toxin. And then this virus infects your natural diphtheroid flora. But what is this lysogenic business means. HELP I am lost....

 

[Myxedema]

If it were just any other virus, it wouldn't be a lysogenic conversion. DNA coding for the diphtheria toxin is carried by a temperate bacteriophage virus. When this virus infects non-pathogenic Corynebacterium strains, viral DNA containing the code for the toxin is integrated into the bacterial genome. This allows toxin to be synthesized. Bacteria which are not infected by this particular bacteriophage carrying the code for the toxin cannot synthesize the toxin and are thus non-pathogenic.

 

[dozer1]

So when they say "lysogenic organism" they mean lysogenic bacteriophage? only

 

[Myxedema]

Yes, organisms which undergo replication in lysogenic cycles are viruses.

 

[ucil]

i'm watching the conversation, nice to see here why are they use that 3 drugs to treat chlamydia.

Go for STD test, get your STD test kit and you able to have confident test at your home.