The Australian Pharmaceutical Benefits Scheme (PBS) is currently under review. In particular, the reference price paid for generic drugs is of concern. It is of interest to compare the reference price (in Aus $) of four commonly used medications.

In Australia, 30 tablets of enalapril 10mg cost $19.21 (NZ$6.20). The cost of 28 capsules of fluoxetine 20mg in Australia is $23.50 (NZ$6.81). Simvastatin 20mg—in Australia 30 tablets are expensive at $47.90 and cost $16.30 in NZ. One hundred tablets of metformin 500mg are $14.20 over the Tasman and $7.93 in NZ. And the NZ prescription co-payment of NZ$15 seems trivial beside the Australian co-payment of Aus $30.70.

PHARMAC take a bow.

Diarrhoea is a common side effect of antibiotics; it may prolong hospital stay, increase the risk of other infections, develop into more serious forms of disease (colitis, toxic megacolon), and lead to premature discontinuation of the needed antibiotic.

Clostridium difficile is responsible for around 15–25% of such problems, taking advantage of the damaged bowel and producing significant toxaemia after colonisation. Probiotics are living, beneficial bacteria or yeasts that are taken orally to help restore the microbial balance in the intestinal tract.

Would routine use of probiotics prevent or ameliorate antibiotic related diarrhoea? In this report the answer is yes as their randomised trial shows an absolute risk reduction of 17% and, in particular, appears to have eliminated C. difficile in the probiotic arm.

An editorial commentary supports the use of probiotics in such patients. However your reviewer notes that subjects taking high risk antibiotics (clindamycin, cephalosporins, aminopenicillins) were excluded, which rather diminishes the results.

It is known that warfarin is highly effective in the prevention of stroke in atrial fibrillation, with a 64% risk reduction compared with 22% for aspirin. This randomised trial compares these treatments in approximately 1000 patients who were 75 years of age or older.

Warfarin was superior to aspirin in the prevention of stroke (1.8% vs 3.8% per year) and was no more hazardous than aspirin in terms of major haemorrhage (1.9% vs 2.0% per year).

However, the absolute annual risk reduction was disappointingly low at 2%. The authors conclude that anticoagulation with warfarin is safe unless there are contraindications. One notes that the cohort of patients randomised (973) was matched by 979 patients excluded on grounds of unsuitability.

Prescription of warfarin remains a very serious matter.

This paper from the US Food and Drug Administration (FDA) comes up with some chilling statistics. It starts off by pointing out that in the US the number of dispensed outpatient prescriptions for warfarin increased 45%, from 21 million in 1998 to nearly 31 million in 2004.

Warfarin is among the top 10 drugs with largest serious adverse event reports submitted during 1990 and 2000 decades. And furthermore, from US death certificates, anticoagulants ranked first in 2003 and 2004 in the number of total mentions of death causing “adverse effects in therapeutic use”.

The authors point out that a “black box” warning about warfarin’s bleeding risk was added to the US product labelling in 2006, but feel that clinicians need to be more proactive with information for their patients. No argument with that.

A debilitating disease of uncertain cause that develops in patients with advanced chronic kidney disease and end-stage renal disease.

Ninety percent of these patients are dialysis-dependent, although non–dialysis-dependent patients with advanced chronic kidney disease and patients with acute kidney injury have been described.

It is characterised by fibrosis, predominantly of the skin, but involvement of the liver, heart, lungs, diaphragm, and skeletal muscle also has been reported with fatal consequences. In about one-third of the cases, exposure to gadolinium from magnetic resonance imaging in patients with chronic kidney disease has been linked to the phenomenon, so gadolinium imaging should be avoided.

So, a nasty sting in the tail of a nephrological success story.