Antibiotic Question Re: treatment of Osteomyelitis

[Mensfuff]

Hey there,

I'm a pre-reg pharmacy student and have recently put a fair bit of emphasis into studying anti-biotics (uses and pharmacology). I have a question, and can't seem to find a straightforward answer, so I thought i'd ask here.

In the County Durham and Darlington Foundation Trust, the first line treatment for Osteomyelitis is Sodium Fusidate + Flucloxacillin.

My question is; Is Sodium Fusidate a bacteriostatic (as i have read)? Penicillins require bacterial growth to be effective, so if you prevent the bacteria from growing with the Fusidic acid how do you actually kill the bacteria that are causing the infection?

Any information/answers would be greatly appreciated

[johnep]

I used to sell Fucidin for osteo many years ago. Cannot now remember whether cidal or static. If the latter then the white cells will mop up bacteria remaining. Main thing re Fucidin is its penetrating power into tissues. Thought to be due to the molecule being steroid like in shape.
johnep

[Mensfuff]

I used to sell Fucidin for osteo many years ago. Cannot now remember whether cidal or static. If the latter then the white cells will mop up bacteria remaining. Main thing re Fucidin is its penetrating power into tissues. Thought to be due to the molecule being steroid like in shape.
johnep

If i recall correctly, fusidic acid shouldn't be used 'alone' as resistance develops quickly and easily (singe point mutation in Fus4 gene i think). If fusidic acid penetrates the bone well and stops the bacteria growing (leaving them to be mopped up by the White Cells), then is Fluclox used as a prophylactic measure against bacteraemia?

[johnep]

Yes often used together with Rifampicin/erythromycin as well. Treatment period for topical not more than two weeks and not in hospital. Although has been used for trachoeostomies.

Interesting point is that although fairly easy to induce resistance, the resistant bugs not very viable and tend to disappear.

I have always wondered why they have not synthesised fluoro or other derivatives, or found something like clavulanic acid to take at same time.

Would be interesting to see if anything done in the past, if not then could be good topic for research.
johnep

[Mensfuff]

Yes often used together with Rifampicin/erythromycin as well.....

So the Fluclox doesn't affect the infection in the bone as much as it prevents a secondary infection occurring.

Strange treatment strategy. I understand the use of Fusidic acid as it penetrates the tissues extremely well, however it would have no effect at ending the infection (is this why the infection takes so long to treat?).

Thanks for the insight johnep, it's nice to feel someone else has a vested interest in pharmacology.

[johnep]

Many papers from 60s showing complete clearance with Fusidic acid after upto 20 years of chronic osteo. Trouble is. the papers were years before computer databases so may not show up in seach. Try Larsen, a name I seem to remember. When I log off will have a look myself.

The Lancet at the time had a whole issue devoted to Fusidic acid. Could well be in their archives.
johnep

[johnep]

ANTIBIOTIC THERAPY OF CHRONIC POST-TRAUMATIC OSTEOMYELITIS
G. Hierholzer 1; J. Rehn 2; H. Knothe 3; ; and J. Masterson
Found this paper after search on chronic osteo and fusidic acid.

Good results were obtained.
johnep