Sunday, September 20, 2009

Pharmaceutical Mathematics

So today's question is:

If a 40mg tablet costs $x how much does a 20mg tablet of the same drug cost?

In the case of Astrazeneca's nexium the answer is a surprising $x.

So why don't people buy the 40mg tablets and split them? Well apparently they are not designed to be split like that.

I suppose we are supposed to be happy that Astrazeneca have decided those that need a large dose of their drug should be subsidised by those requiring a smaller dose.

I'm wondering how prevalent this sort of pricing is.

Thursday, September 17, 2009

Mixing bikes and pedestrians

It has been a bad summer for cycling in Ottawa, another cyclist died yesterday.

Over the summer I have read a number of pieces suggesting increasing tension between cyclists, pedestrians and drivers.

I've seen claims that cyclists and pedestrians don't mix any better than cyclists and cars.

One wrote that there is little difference between a cyclist doing 30km/h plus car doing 60km/h or a cyclist doing 30km/h and a pedestrian doing close to 0km/h.

I have to disagree with this. First off, 30km/h is top end of the range for cyclists, 0 bottom for pedestrians and 60km about par for a car, assuming 60km/h limit. Realistically thoug, the cyclist will be doing more like 20km/h and the pedestrian 6km/h, so the speed difference is as 14km/h in that case and 40km/h car to cycle.

The relative speed is of course a factor in generating accidents, but then you have to consider the damage when there is an accident. The energy involved is proportional to the square of the velocity. So, even if you ignore the mass of the car, there is 4 times the energy in a car/bike collision than bike/pedestrian. Throw in the mass of the car and it is off the scale.

Now on Sunday, I went for a run along the canal. It was a lovely sunny afternoon, some of the trees just starting to turn colour with joggers, cyclists, walkers and people casually strolling all mixing with no problems at all. Cyclists were courteous, ringing their bells to warn of their approach, slowing if necessary. Walkers were keeping to the right side of the path, aware they are sharing with others. Lots of give and take, everyone having a safe and fun time.

If only there was the same give and take between cars and cycles.

Thursday, September 10, 2009


On a moped, smoking, drinking and phoning