Actonel vs. Fosamax: What’s Better?

Summary: Clinically I haven’t found there to be a big difference between Actonel or Fosamax. I see much more Fosamax prescribed, though. This is probably a combination of Fosamax being available as a generic and being much cheaper as well as it being first to market. Some online resources claim that Fosamax shows no evidence in helping hip fracture risk. That’s false.

Dear Curtis: At my last appointment my doctor and I started talking about putting me on a medication to treat my early osteoporosis. At this point it’s Actonel vs. Fosamax. He says those are the two most popular and that they both work the same way and have the same side effects. He told me to look into the cost of them and then he would write for whichever one I preferred.

Do you agree with him? Are they pretty much the same thing? I want to make the best decision I can.

Please note: I’m referring to the once weekly forms of both drugs. These tend to be the most common forms.

If you look around or read at all online you’ll find if there is any ‘knock’ on Fosamax it is because it doesn’t have evidence showing that it helps hip fractures. Which, is a big deal because hip fractuers are not only a common spot for fractures in older folks – but it can be very hard to treat and recover from.

The biggest problem with this information is that it’s not true.

Fosamax does have evidence proving it’s effectiveness in lowering hip fracture risk.

In fact, in a 3 year study involving Fosamax in over 2,000 folks there was over a 50% reduction in hip fracture risk and just under a 50% reduction in spine fracture risk.

I don’t bring this up because Fosamax is ‘better’. Just to point out that some of the things you are going to read and hear about either of the drugs will likely be false.

With that being said there are some differences between the drugs.

Which drug do I see prescribed more often?


This is by a large margin. But, I wouldn’t put a ton of weight in this because a lot of drugs are prescribed for different reasons. Some of them are geographical. Some of them, like the case of Fosamax, are because Fosamax was the first on the market. So doctors get comfortable prescribing it and form habits. Habits aren’t broken easily.

Even more important is the price difference. Fosamax has a generic form available. Actonel doesn’t. I talk more about the price difference below.

Which drug has more side effects?

Understand that Fosamax and Actonel are both in the same drug class and essentially act the same way. I haven’t found a big difference on way or the other as far as side effects go. Both drugs can cause some muscle pain and abdominal pain or cramping. Headache is seen in studies more often than a sugar pill.

Basically, I’d consider this a wash. I haven’t found one drug to be tolerated that much better than the other.

How about drug interactions?

No real differences worth noting in my opinion. You have to watch both drugs if you take any sort of antacids, calcium and iron supplements or NSAIDS like aspirin which can increase your risk of upper gastrointestinal tract problems.

Dosing differences?

Both drugs come with the risk of esophageal problems.

However, there is a major difference between the extended-release formulations of these drugs. Actonel is designed to be taken after breakfast. Fosamax is designed to only be taken with water in a fasted state ½ hour before breakfast.

The difference in the two drugs is due to how fast and how much of the drug was absorbed in studies. Food actually helped Actonel and hurt Fosamax.

Please note: if you take the daily (immediate-release) type of Actonel then you want to go back to taking it in the fasted state. But, as I mentioned above I’m just focusing on the once weekly formulations of both drugs.

What does the evidence say?

They both work. Period.

If you pick apart the studies you can find small differences between both drugs. Essentially, they kind of even out over the long haul.

Remember, these drugs act the same way and are in the same drug class. While there were differences in the clinical studies I’m not comfortable saying that they were really big enough to make a difference.

Which one is cheaper?

Fosamax. By a large margin.

It’s been available as a generic for a while now.

I’d encourage you to shop around a bit if you are paying cash. You’d be surprised how much prices fluctuate from pharmacy to pharmacy.

With that being said, if you pay straight-up cash for both once a week drugs you’ll probably find that Fosamax (the generic called alendronate) is about 30% to 50% the cost of Actonel. Actonel is not scheduled to become available generically until 2013.

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