The first line drug for osteoporosis, Alendronic Acid (fosomax) comes with very precise instructions on how to take it. It should be taken with a large glass of water (further research says this ‘large glass’ is 200ml / 7fl oz) after getting up in the morning. No eating in the middle of the night….they really really want your stomach to be empty. No eating for at least half an hour after taking the pill, and stay vertical (sitting upright or standing).
These pills used to be taken everyday, and I can see that this set of instructions, seemingly so simple, would be quite a hassle with a busy life and no respite. With the one a week dosing it is pretty simple to manage.
But why the emphasis on not taking the pills with breakfast – the easiest time of day to remember to take pills? So easy that I discovered Bestbeloved was taking pills he shouldn’t take with meals along with all the others he has to take in one large handful with his breakfast.
The reason we need to avoid food as that very little of the drug gets absorbed into the bones. Most of it just gets eliminated.
This is a quote from the MRHA – the Medicines and Healthcare Products Agency
“5.2 PHARMACOKINETIC PROPERTIES
Relative to an intravenous reference dose, the oral mean bioavailability of alendronate in women was 0.64% for doses ranging from 5 to 70 mg when administered after an overnight fast and two hours before a standardised breakfast. Bioavailability was decreased similarly to an estimated 0.46% and 0.39% when alendronate was administered one hour or half an hour before a standardised breakfast. In osteoporosis studies, alendronate was effective when administered at least 30 minutes before the first food or beverage of the day.
Bioavailability was negligible whether alendronate was administered with, or up to two hours after, a standardised breakfast. Concomitant administration of alendronate with coffee or orange juice reduced bioavailability by approximately 60%.”
So, if you eat your pill with breakfast none of the drug gets into your bones. If you eat it up to two hours after breakfast, none of it gets into your bones. Taking your pill with coffee or orange juice instead of plain (low calcium) water means more than half of it is wasted.
It doesn’t help that almost all of the drug passes straight through anyways, however careful you are. Being totally careful about taking the pill, overnight fast, two hours before breakfast and with plain water, you still only get to use less than one percent (0.64%). This is halved if you have your breakfast half an hour later, which is what the packaging says is the amount of time you need to leave between taking the pill and eating breakfast.
Question is, given that the dosing is planned around people eating half an hour later, is it bad for me to wait an hour or two to get more of the bone hardening drug into my bones or not?