Hi,

Very relevant question. Browsing through the literature, practically no-one reports how they calculate the doses! Should be done appropriately from now on. In order to compare the results in various articles the manner of reporting should be known. Thank you for your wake up call! Highly appreciated.

The point of how to report doses or concentrations may be especially confusing when coming to electrolytes like Mg if not given in mM or mEq. Noradrenalin, however, in my experience is only given as NA base. The important thing is how it is written on the ampoule as this is used for the protocols on the syringe pumps. It is logical to use the active substance and I would think this is used by most authors. It would create a massive confusion and be dangerous if the nurses should set up syringepumps or infusions if the concentrations in the ampoules are not used for the infusions. I am not avware of ampoules labeled with the tartrate concentration as the main label. It may be given as an explanatory addition like: 1 ml contains 1,99 mg noradrenalin tartrate equivalent to 1 mg noradrenalin base. It would be interesting to hear whether the drug is labeled otherwise in the different countries.

I am sorry, but very few physicians are aware of the fact that NE is bivalent and thus is only available in the BITARTRATE salt.

Thus, many physicians think that they use 1mg/hr for instance (1mg of bitartrate) whereas the IV administration is only of 0.5mg/hr of NE base . In a french survey done by one of our young fellow, less than 10% of the intensivists enrolled knew that they use Bitartrate NE. In this survey, only two authors among nearly 100 , use NE base dose for their publication.

In clinical pratice, it is much easier to use BItartrtate doses of NE, but for our publications, we have to report Bitartrtate NE ( BiNE) or NE base ( BiNE/2).

Consensus for reporting NE doses is, at evidence, required.

PS as in many countries drug is labelled bitartrate NE (4 mg/ 4ml), which correspond for the 4 ml to 2 mg of NE base.

The question is very pertinent as there is very often a confusion between the actual NE dose and the dose of NE in its salt form (bitrartrate). In clinical practice, I believe most clinicians (wrongly) express the dose as bitartrate as if it was the actual NE dose.

I agree that documents and research papers should clarify the way they report NE doses.

Our group is planning to start a Clinical Trial using NE. What would be the recommended way to clarify the dose used? Thanks.

I think dose is always according to the NE base. In case of study/trials, that should be followed. NE should mean NE base, unless mentioned otherwise.

Basically we should not bother about specific salts. Today we are using Bitartrate salt, in future some other salt may come up. If we go on using the NE base for dosage, our dosage calculation will not be hampered whatever salt do we used.

For a clinical trial usine NE, i Will suggest to use bitartrate NE for data collection and to specify in the materials and methods section: bitartrate NE ie 0.5 mg or NE base.

Thus , There will be no more confusion.

Australia prescribes as NA as NA base.

In all references the dose of NE is based on base. In products which we have in Iran clearly it has been mentioned that NE 8mg equal to NE base 4mg and we consider each amp. 4mg in our practice.

Thanks for your informations about Iran, however i am not sure that all the doses reported in the literature are based on NE base. Indeed, in all the international trials our goup participated, as others, we reported NE use in bitartrate NE.. Moreover, if you focus on the materials and methods section, authors do not mention if they report base or bitartrate NE.

Despite the mention that bitartrate NE 8 mg is equal to 4mg of NE base, very few ICU's know this fact, as we did during many years....