Australia to adopt INNs

The Therapeutic Goods Administration (TGA) has announced that it will proceed with international harmonisation of drug names used in Australia from April 2016. For the past decade or so, since the United Kingdom moved to the World Health Organization’s International Nonproprietary Names (INNs), we’ve been in the anomalous situation of using former British Approved Names despite these no longer being used in the UK (nor listed in the British Pharmacopoeia). The TGA website has a list of affected drugs.

Some changes are trivial:

  • Substitution of “ph” with “f” (e.g. cefalexin, guaifenesin)
  • Substitution of “y” with “i” (e.g. amoxicillin, ciclosporin)
  • Substitution of “th” with “t” (e.g. indometacin)

Others are more significant (and will require dual-labelling for 3 years), for example:

  • Dosulepin (dothiepin)
  • Formoterol (eformoterol)
  • Furosemide (frusemide)
  • Glycopyrronium bromide (glycopyrrolate)
  • Hydroxycarbamide (hydroxyurea)
  • Lidocaine (lignocaine)

On the contentious subject of adrenaline vs epinephrine, the TGA has followed the UK practice where dual-labelling “adrenaline (epinephrine)” will be used indefinitely.

eGFR vs CrCl

Estimated glomerular filtration rate (eGFR) and creatinine clearance (CrCl) are often, incorrectly, used interchangeably when discussing renal function and drug dose adjustment.

Creatinine clearance, usually estimated using the 1976 Cockcroft-Gault formula rather than actually measured by (notoriously unreliable) 24-hour urine collection, has traditionally been used for drug dosing as it is relatively standardised despite overestimating renal function due to tubular secretion of creatinine. In addition to the usual caveats associated with basing renal function estimates on serum creatinine (acute illness, muscle mass, diet, etc), accuracy of the formula is limited by changes to serum creatinine assays and the rise in obesity since 1976.

Renal function is assessed nowadays using formula-derived eGFR (actual GFR is impracticable to measure routintely). Until recently this was usually calculated using the MDRD formula (1999), which has been well validated but has limited accuracy above 60 mL/min. Laboratories in Australia now report eGFR calculated using the superior CKD-EPI formula (2009). Although both of these formulae give better estimates of true renal function (GFR) than CrCl, they are both still based on serum creatinine with its associated caveats above.

Some studies have shown a reasonable concordance between CrCl (Cockcroft-Gault) and eGFR (MDRD) with respect to drug dosing,1 whereas others have noted significant differences.2–3 At the end of the day, CrCl and eGFR are not the same thing and prescribers should remain vigilant as to which measurement has been used to formulate dosage adjustment recommendations.

References:
1. Stevens LA, et al. Am J Kidney Dis 2009;54:3342
2. Wargo KA, et al. Ann Pharmacother 2006;40:124853
3. Park EJ, et al. Ann Pharmacother 2012;46:117487

Biotechnology descriptors

Whilst giving a presentation at grand rounds recently, I noted that approved names for biological medications in Australia are suffixed with a three-letter abbreviation – the “biotechnology descriptor” – to indicate the biotechnology production system used, e.g. insulin lispro (rbe).

The most common biotechnology descriptors are:

  • ghu – gene-activated human cell line
  • rbe – recombinant bacteria Escherichia coli
  • rch – recombinant Chinese Hamster ovary cell line
  • rmc – recombinant mouse cell line
  • rys – recombinant yeast Saccharomyces cerevisiae

Incidentally, I cringe whenever someone refers to this group of medications as “biologics” – an Americanism that has crept into the Australian medical lexicon. Australian English still retains the “-ical” ending (rather than shortening to “-ic” in American English), therefore we should continue to refer to these medications as “biologicals”.

How not to get elected

Ballots closed recently for the Pharmacy Council of New South Wales 2013 election. Voting as a registered pharmacist in NSW, I was only familiar with a few of the candidates and so had to rely on the Candidate Information Sheet that was sent out. I’ve reproduced page 4 below (de-identified)…

Page 4, Candidate Information Sheet, Pharmacy Council of NSW election 2013

The nomination paperwork clearly indicated that the “candidate information” section would be reproduced exactly as submitted… The candidate at the top of the page did not get elected.

A tale of four tutors

Four tutors at two Group of Eight universities in Sydney in the past two weeks: an allegory on some of the qualities of good teachers…

Tutor A teaches medicine. Although qualified in a clinical health science, she had little understanding of the subject material nor demonstrated any convincing attempt to do so. She did not attempt to establish rapport with the students in her class.

Tutor B teaches clinical sciences. Whilst clearly qualified in the majority of the subject material taught, he then attempted to teach some material which he didn’t understand (in a field where some of the graduate students in the class were qualified). He did, however, attempt to establish rapport with the students in his class with some success.

Tutors C & D teach in the Faculty of Pharmacy at USyd and the Faculty of Medicine at UNSW respectively. Although both are relatively young, they proactively ensure that they each have a thorough knowledge and understanding of the material taught. Appreciating the importance of connecting with students, they both make a high priority of establishing good rapport with the students in their respective classes.

Who would you prefer as your tutor?

Dysphasie en français

The hospital I work at has an arrangement with the New Caledonian private health fund Caisse de Compensation des Prestations Familiales des Accident du Travail et de Prévoyance Familiales des Travailleurs de la Nouvelle-Caledonie et Dépendances (CAFAT), which means that we regularly have French-speaking patients under our care – many of whom have little command of English.

Recently, I needed to check whether one of our CAFAT patients had any more of her own supply of gabapentin. Having established that she didn’t understand any English, I was forced to deploy my very rudimentary French…

Me: Bonjour madame, je suis le pharmacien… Avez-vous plus de la gabapentine?
Pt: Looks at me blankly. Pharmacien?
Me: Oui. Avez-vous plus de la gabapentine?
Pt: Matin et soir… « unintelligible »
I try a different tack and show her the tablets remaining in her medication drawer.
Me: Voici deux comprimés de la gabapentine. Avez-vous plus?
Pt: Un le matin… « unintelligible »
Me: Oui, mais avez-vous plus de comprimés? Plus?
Pt: « unintelligible »
At this point I give up…
Me: Ok, merci.

I later noted that the reason for admission was a central nervous system (CNS) lesion. At this point I realised that she probably had dysphasia secondary to the CNS lesion… so perhaps it wasn’t (just) my bad French!