Question on Augmentin Duo and generics

Nonoperational

Hey,
I've seen a few scripts recently for co-amoxiclav 625 bd F7. I was under the impression that this was poor prescribing as the concentration (particularly of the clavulanante) gets too low between doses. As far as I know Augmentin Duo is the only co-amoxiclav that should be prescribed bd as the standard co-amoxiclavs such as Pinaclav and Clavamel are not modified to be dosed bd and should be dosed tds. Hard to find a good reference to back this up. Anyone shed some light on this for me? Thanks

SomeDose

It is unusual although, in theory at least, high doses (500mg and above) of amoxicillin can be dosed bd. The clavulanate has a shorter half-life so I'm not sure if effective peak plasma concentrations would be reached in this case. Something like Martindale might give you some more info. Another possibility is if the patient has some degree of renal failure, in which case bd dosing wouldn't be unreasonable.

ZYX

gpf101 wrote: »

Hey,
I've seen a few scripts recently for co-amoxiclav 625 bd F7. I was under the impression that this was poor prescribing as the concentration (particularly of the clavulanante) gets too low between doses. As far as I know Augmentin Duo is the only co-amoxiclav that should be prescribed bd as the standard co-amoxiclavs such as Pinaclav and Clavamel are not modified to be dosed bd and should be dosed tds. Hard to find a good reference to back this up. Anyone shed some light on this for me? Thanks

Did you get this from Augmentin rep? I have always wondered why Augmentin became so popular in this country. It seems to be 1st line for everything despite clear guidelines stating the opposite. If you are a Dr contact your microbiology lab. While in theory there may be a difference, in practice there isn't.

Nonoperational

Renal failure isn't an issue asaik. I think augmentin DUO is formulated to make the clavulanante slow release allowing bd dosing. I dont think pinaclav is equivulent. I'll dig into it and try get some more info. Any doctors in the infectious disease area / antibiotic resistance areas have any input?

Ausone

The half life of Amoxicillin in Augmentin in approx 1.3 hours
Clavulanic Acid is approx 1 hour.

See http://us.gsk.com/products/assets/us_augmentin.pdf

For Irish info see www.medicines.ie

Augmentin Duo is not a prolonged release preparation. Compare it to Germentin on the medicines.ie website.

Generic co-amoxiclavs are not licensed for use BD. They didn't have enough info or bother to get the (expensive) data to get it past the IMB.

GSK have made a big play on pharamacodynamics recently dosing with Augmentin and bioavailability with Lamictal to name two.

AFAIK the only difference is bioavailability (v small) and licensing.

If a prescriber writes a RX for Pinaclav 625 BD it is an unlicensed use and liability fall back on them.

Hope this helps.

Nonoperational

interesting, thanks. I was planning to look up the pk properties! so augmentin duo is basically the same product with a different licence?

SomeDose

Augmentin Duo has different quantities of the 2 components and is licensed for use in children. However I imagine it's seldom used instead of the regular tds preparations - I certainly have never seen it used in any paediatric cases.

Ausone

AFAIK They are exactly the same except for excipients. (Bioavailability will differ naturally)

I was around when Augmentin lost it's patent. GSK would have made a much bigger play re BD dosing if it was relevent.

In adults in the community Augmentin tds has effectively stopped. The BD preps are prescribed way more.

With children tds and bd Augmentin are about 50:50. (personal experience)

Depends on the prescriber and history.

DrIndy

ireland has a prescribing pattern of giving co-amoxiclav 500/125 BD whereas in the UK its is almost always TDS - this is individual pattern to the best of my knowledge between countries with no specific reason for it.

I normally give TDS - but i have an interest in antibiotics and ID.

Nonoperational

Thanks.

SomeDose

Ausone wrote: »

AFAIK They are exactly the same except for excipients. (Bioavailability will differ naturally)

I was around when Augmentin lost it's patent. GSK would have made a much bigger play re BD dosing if it was relevent.

In adults in the community Augmentin tds has effectively stopped. The BD preps are prescribed way more.

With children tds and bd Augmentin are about 50:50. (personal experience)

Depends on the prescriber and history.

My apologies, it seems the UK and Irish markets are quite different in this respect. Augmentin Duo in the UK is specifically a 400/57 paeds preparation and nothing else, whereas Ireland also has an Augmentin Duo 500/125 bd product. As DrIndy says, Ireland seems to have a preferentially bd co-amoxiclav prescribing pattern.

For the life of me I cannot understand why this is so....

Ausone

SomeDose wrote: »

For the life of me I cannot understand why this is so....

Economics. Price of generics and patent protection. GSK exist to make money, not medicines.

SomeDose

Ausone wrote: »

Economics. Price of generics and patent protection. GSK exist to make money, not medicines.

I'm aware of the non-altruistic traits of pharmaceutical manufacturers. I was referring to the prescribing habits in Ireland, and the preference to give the product bd when the traditional tds usage works perfectly well.

Ausone

As drug costs in Ireland are high (both generic and proprietary).
GSK was advantaged by introducing the BD Duo product.
It was a form of patent protection, and they put a lot of money into detailing and marketing.
They have managed to increase both penetration and market share, from my experience.
Advertising works!

ZYX

Ausone wrote: »

As drug costs in Ireland are high (both generic and proprietary).
GSK was advantaged by introducing the BD Duo product.
It was a form of patent protection, and they put a lot of money into detailing and marketing.
They have managed to increase both penetration and market share, from my experience.
Advertising works!

Very true. UK doctors are much more careful re prescribing. Some PCTs (Primary Care Trusts) effectively ban doctors from prescribing certaining drugs. Augmentin Duo may be one, although I don't know for certain.