Why must Fosamax^® be taken so early in the morning?

Bisphosphonates (e.g. alendronic acid (Fosamax^®, Fosavance^®: Fosalan^®, Fostopar^®, Tevanate^®), risedronate (Actonel^®) etc), are a class of drug which are used to treat osteoporosis and other conditions involving the bones. They must always be taken approximately one hour before other drugs or food, while sitting or standing upright, with plenty of water, and remain sitting or standing until the hour has passed. The most convenient time is therefore first thing in the morning.

The reason is that these drugs combine with any calcium, magnesium or iron in food or drugs. Rather than have patients try to remember which foods contain these elements (milk, yoghourt or cheese, for example) or which drugs (calcium tablets, antacids, iron tablets, multivitamin tablets for example), it is easier to issue a blanket proscription to the patient. This is made less of a burden by the fact that these tablets need only be taken once a week or once a month.

The other important point is that the patient take the tablet with plenty of water; i.e. a mouthful before the tablet, with the tablet and finally a mouthful after swallowing, while standing or sitting upright. The patient must not take the tablet while lying in bed, or return to bed afterwards. This is because there is a rare, but serious condition called oesophagitis which can occur if the elderly with swallowing difficulties take the tablet with insufficient water and while lying prone. If the tablet lodges in the gullet, it can be severely irritating and cause this condition.