Bone Health

Slowing bone loss: alendronate and raloxifene

When a scan shows thinning bone, a bisphosphonate is the standard first medicine, and Alendronate is the one stocked here. Fosamax, also sold as plain alendronate, comes as 35mg and 70mg tablets taken once a week, listed for osteoporosis and Paget's disease of bone (where bone renews too fast and grows misshapen). The drug settles onto the bone surface and slows the cells that break bone down. Nothing about it is felt day to day: the benefit is fewer fractures over years, tracked by bone density scans.

Raloxifene takes a different route. A 60mg tablet, it acts like oestrogen on bone without stimulating breast or womb tissue, and it is listed for osteoporosis after the menopause. It can cause hot flushes and leg cramps, and it raises the risk of blood clots, so it is not a medicine for anyone with a history of them.

Vitamin D analogues for low calcium

Ordinary vitamin D has to be activated by the kidneys before it works, which is the problem when the kidneys are not doing that job well. Alfacalcidol skips that step. It comes as Alfacip (also sold as plain alfacalcidol) in 0.25mcg and 0.5mcg capsules, with One-Alpha at 0.25mcg, and is listed for low calcium, rickets, osteomalacia (soft bones in adults) and osteoporosis. Rocaltrol holds calcitriol, the fully active form, in capsules for low blood calcium and an overactive parathyroid gland. With either, calcium levels in the blood need checking from time to time, as too much calcium is the main risk.

Calcium tablets, and the one that lowers phosphate

Calcium Carbonate is the plain 500mg tablet for a calcium shortfall, and it also works as an antacid for heartburn. It is absorbed best with food. Calcibrook Forte puts calcium carbonate, magnesium hydroxide and zinc sulphate into one tablet (1000/240/11mg) for people who want minerals together.

Phoslo looks like a calcium tablet but does a different job. Calcium acetate 667mg binds phosphate from food in the gut, which is why it is taken with meals by people whose kidneys no longer clear phosphate, a state called hyperphosphataemia. It belongs in the category because high phosphate drags down bone health, not because it builds bone.

Fitting several together

Calcium and alendronate should be kept apart: alendronate goes in first, and calcium or antacids follow at least half an hour later. Pairing a vitamin D analogue with calcium tablets is common, but it is the reason blood calcium is monitored.