5 Drinks to Avoid While Taking Fosamax (Alendronate)

Alendronate (Fosamax) is a bisphosphonate medication that’s used to prevent and treat osteoporosis. Alendronate works by decreasing bone breakdown — this strengthens bone and helps prevent fractures.  

But Fosamax isn’t the easiest medication to work into your daily routine. Fosamax isn’t well absorbed by the gut. So you have to take it in a certain way to maximize your gut’s ability to absorb the medication. If you don’t absorb enough Fosamax, you won’t get the full benefits of the medication. 

You may already know that you have to take Fosamax at least 30 minutes before your first meal of the day. Taking Fosamax with food can lower absorption by up to 90%. You may also know that you need to take Fosamax with at least 6 oz to 8 oz of fluids. But your choice of fluids matters. Some drinks can affect Fosamax absorption. Here are five drinks to avoid while taking Fosamax.   

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1. Milk 

Calcium is essential for strong bones. If you have osteoporosis, you’re probably focusing on calcium-rich foods to support your bone health. Milk and other dairy products are great sources of calcium.

But you shouldn’t take Fosamax with milk. Fosamax binds to calcium in milk, which makes it harder for the gut to absorb the medication. It’s also a good idea to avoid high-calcium foods for at least 30 minutes after taking Fosamax.

If you’re taking calcium supplements, don’t take them at the same time as Fosamax. Fosamax will also bind to calcium supplements, making it almost impossible for the gut to absorb either medication. 

If you’re taking Fosamax once a week, you may need to skip your calcium supplement on the day you take Fosamax. If you’re taking Fosamax daily, make sure to separate Fosamax and calcium supplements by at least 2 hours. Your healthcare team can help you figure out the right schedule based on your calcium and Fosamax doses.

2. Mineral water

There are several forms of alendronate including tablets, oral solutions, and dissolvable tablets. And they all need to be taken with water. But the type of water you use matters. 

You shouldn’t take Fosamax with mineral water. Mineral water comes from underground sources so it naturally contains salts and minerals. Certain brands of mineral water contain high levels of calcium. Calcium can lower Fosamax absorption in the gut, making it less effective. 

Make sure to avoid both still and sparkling mineral waters, the latter is often labeled as “sparkling water.” 

Tap water can also contain high levels of calcium and other minerals. This is often called “hard water.” Take Fosamax with bottled water if you know you have hard water. You can get your water tested if you’re not sure if you have hard water or not. Your local water company can help you choose the best at-home test kit. 

3. Coffee

Coffee is a morning staple for many people. But you shouldn’t take Fosamax with coffee. There have been several studies showing that taking Fosamax with coffee lowers Fosamax absorption by up to 60%. 

It’s not clear why coffee lowers the body’s ability to absorb Fosamax. Scientists haven’t pinpointed whether it’s due to caffeine or another component in coffee beans. Fosamax’s manufacturers state that you shouldn’t take Fosamax with tea either. But you can drink coffee, tea, and other caffeinated beverages 30 minutes after taking your Fosamax dose.

4. Orange juice

Orange juice is a great source of antioxidants and vitamin C. But it’s not a good option to wash down your Fosamax dose. Several studies have shown that orange juice decreases Fosamax absorption by as much as 60%. 

It’s not clear how orange juice lowers the gut’s absorption of Fosamax. Fosamax’s manufacturers recommend not drinking orange juice and other fruit juices with Fosamax. It’s a good idea to avoid these drinks for 30 minutes after taking Fosamax. 

5. Electrolyte drinks

Electrolyte drinks, like Gatorade and Pedialyte, can help keep you hydrated, especially if you’re sick or after an intense workout. But you probably shouldn’t take Fosamax with these drinks. Some electrolyte drinks contain magnesium. 

Magnesium can lower your gut’s ability to absorb Fosamax. Experts recommend avoiding medications that contain magnesium if you’re taking Fosamax. The amount of magnesium in electrolyte-containing drinks is much lower than what’s found in medications or supplements. But it’s still a good idea to opt for plain water over these drinks when taking Fosamax. 

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Written by:

Jennifer Sample, MD

After a fellowship, Dr. Sample worked as the medical director at the University of Kansas Hospital Poison Center (The University Of Kansas Health System Poison Control Center), which served the state of Kansas for poison exposures. In 2007, she returned to Children’s Mercy Hospital in Kansas City, Missouri, as a consultant in clinical pharmacology and medical toxicology.

Edited by:

Patricia Pinto-Garcia, MD, MPH

Patricia Pinto-Garcia, MD, MPH, is a medical editor at GoodRx. She is a licensed, board-certified pediatrician with more than a decade of experience in academic medicine.

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