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Water hardness and foolish instructions

I’ve been looking at a lot of issues around medication, posture, exercise and the psychological impact of a diagnosis of osteoporosis. One of the reasons given for poor compliance with medication (people stop taking their pills when the doctors think they should carry on) is the difficulty in coping with the specified way they have to be taken.

Note -alendronic acid or Alendronate is the generic name for this drug, Fosamax is a brand name.

“Taking alendronic acid
It is important that you take alendronic acid in the correct way, as otherwise it can cause irritation and damage as it is swallowed:

Take the tablet/medicine first thing after getting up in the morning. Take it before you eat any food or have anything to drink other than water.
You must drink a large glassful of plain water (not mineral water) as you take your dose. If you are taking tablets, swallow the tablet whole – you must not chew, break, or crush alendronic acid tablets.
It is important that you take your dose while you are standing or sitting in an upright position.
Continue to sit or stand upright for 30 minutes after taking your dose – you must not lie down during this time.
Do not have anything to eat or drink (other than plain water) during the 30 minutes after taking a dose .”  http://www.patient.co.uk/medicine/alendronic-acid-for-osteoporosis-fosamax

You’ll see it says you need to drink “a large glass of water”  – I’ll discuss what this means to the manufacturer and what it means to individuals reading it later.  I want to focus on the phrase not mineral water”.  Now, I grew up in India, where drinking water was boiled and carefully stored, so maybe I think more about water quality than many.  I also had my first job in London, where the water tasted so bad all I drank were tomato cup-a-soup as that was the only think I found that would disguise the flavour.  This predates the ready availability of water filter jugs and bottled water.

I’m also the kind of person that want to know “why not”  and “why do you think that” whenever I hear an instruction.

So why not mineral water?  It turns out that calcium in the water affects the absorption of the drug.

Calcium in water is good for your heart and bone health, and hard water is one of the major sources of calcium for many people.  Water hardness is a sufficiently big component of calcium availability that it has been recommended that GP’s should know the water hardness in their areas http://www.sld.cu/galerias/pdf/sitios/rehabilitacion-bal/how_much_calcium_is_in_your_drinking_water.pdf  .  This same report said that the manufacturers of the pills didn’t know what effect the calcium had on bioavailability of the drug so wouldn’t give a recommendation on the maximum level.

So, don’t take these pills with mineral water as it will reduce the availability and absorption of the drug.  BUT- tap water varies a lot.  Mineral water varies a lot.  I checked the calcium level of my tap water using my suppliers on-line ‘enter your postcode’ service.  I have medium hard water.  I checked the calcium level of the bottled water I keep for trips (very cheap stuff from the supermarket).  That had about one-tenth the amount of calcium in it.  I’d be better off using the mineral water rather than the tap water to take my pill.

I’m not the only one that thinks this is ridiculous.  R.Pelligrini of Bologna University wrote

 “the aforementioned formulation of the package insert is practically a nonsense, owing to the well-known huge differences among waters, both tap and mineral,”http://paperity.org/p/10789431/which-water-for-alendronate-administration

The amount of calcium in water to take the pill with should be specified, then people can make an informed choice.  I discovered that I could get calcium testing kits from the local aquarium/pet fish supply shop for a few pence a time.  I got sent a water hardness test strip with a dishwasher I bought a few years ago.  It is not difficult or expensive to test your water hardness.  Bottles of water specify their mineral content. Deciding which water to use would be easy if one knew the calcium level that didn’t compromise absorption.

Why does this matter?  People could be reducing the effectiveness of their medication by following this ruling.  If they dislike the flavour of their tap water this will make the whole process even less pleasant and possibly reduce compliance.  It also makes it feel arbitrary and controlling – instructions without clarity, a “must” without a reason.  Add to that, if you research the issue it turns out to be nonsense.  What else might one go on to mistrust?

There is also the issue of safety.  I read a query sent to an online help desk for arthritis sufferers.  The questioner said they were about to travel and how could they safely take their alendronate in places where they didn’t know if the tap water was safe to drink.  The reply was  to say tap water was safe in most European countries (the traveller didn’t say where in the world they were planning to go).  I didn’t keep a reference to that question and answer, but it has stuck in my head.  Go ahead, die of dysentery, but don’t take your pill for a long standing, possibly eventually disabling, ailment with bottled water.  Now that is a ridiculous piece of health advice.

 

 

Apologies for the references being such long links in the middle of the text.  I used Google Blogger for years and found shaping my links very easy but WordPress is defeating me for some unknown reason.  I’ll keep working on improving my knowledge and skill.

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