What is Sevelamer: Uses, Dosage, Side Effects and More

Sevelamer is a prescription medication that helps control high phosphorus levels in your blood, especially if you have kidney disease. It works like a helpful sponge in your digestive system, binding to phosphorus from the food you eat so your body can't absorb too much of it.

This medication becomes particularly important when your kidneys aren't working well enough to filter out excess phosphorus naturally. By keeping phosphorus levels balanced, sevelamer helps protect your bones, heart, and blood vessels from potential complications.

What is Sevelamer?

Sevelamer is a phosphate binder that belongs to a class of medications called bile acid sequestrants. Unlike some other phosphate binders, it doesn't contain calcium or aluminum, which makes it a safer long-term option for many people with kidney problems.

The medication comes in two main forms: sevelamer carbonate and sevelamer hydrochloride. Both work the same way, but sevelamer carbonate is often preferred because it's less likely to cause acid buildup in your body. Your doctor will choose the right form based on your specific health needs.

What is Sevelamer Used For?

Sevelamer is primarily prescribed to treat high phosphorus levels in people with chronic kidney disease who are on dialysis. When your kidneys can't properly filter phosphorus from your blood, this mineral builds up and can cause serious health problems.

High phosphorus levels can lead to bone disease, making your bones weak and painful. It can also cause calcium deposits to form in your blood vessels, heart, and other soft tissues, which increases your risk of heart problems and stroke.

In some cases, doctors may prescribe sevelamer for people with kidney disease who aren't yet on dialysis but have persistently high phosphorus levels. The medication helps prevent complications before they become more serious.

How Does Sevelamer Work?

Sevelamer works by binding to phosphorus in your digestive tract, preventing your body from absorbing it. Think of it as a magnet that attracts phosphorus from the food you eat, then carries it out of your body through your stool.

This is considered a moderately strong medication for phosphorus control. It's quite effective at what it does, but it's not the most powerful option available. The strength is actually an advantage because it allows for better control and fewer severe side effects compared to stronger alternatives.

The medication doesn't get absorbed into your bloodstream, which means it only works in your digestive system. This localized action makes it safer for long-term use, especially for people who already have compromised kidney function.

How Should I Take Sevelamer?

Take sevelamer exactly as your doctor prescribes, usually with meals. The timing with food is crucial because the medication needs to be present in your stomach when phosphorus from your meal arrives.

Swallow the tablets whole with a full glass of water. Don't crush, chew, or break them, as this can interfere with how the medication works. If you have trouble swallowing tablets, talk to your doctor about other options.

You can take sevelamer with or without other medications, but space them apart by at least one hour. This prevents sevelamer from binding to your other medications and reducing their effectiveness. Your pharmacist can help you create a schedule that works best for your medication routine.

It's generally safe to take with most foods, but try to maintain consistent eating habits. Having regular meal times helps ensure the medication works consistently day after day.

How Long Should I Take Sevelamer For?

Most people with chronic kidney disease need to take sevelamer for the long term, often for years or even the rest of their lives. The duration depends on your kidney function and how well your body responds to treatment.

Your doctor will monitor your phosphorus levels regularly through blood tests, usually monthly at first, then less frequently once your levels stabilize. Based on these results, they may adjust your dose or discuss whether you can eventually reduce or stop the medication.

If you're on dialysis, you'll likely need to continue taking sevelamer as long as you're receiving dialysis treatment. Some people who receive a kidney transplant may be able to stop taking phosphate binders, but this depends on how well their new kidney functions.

What Are the Side Effects of Sevelamer?

Like all medications, sevelamer can cause side effects, though not everyone experiences them. The most common side effects affect your digestive system since that's where the medication works.

Here are the side effects you might encounter, keeping in mind that most people tolerate this medication quite well:

• Nausea and vomiting, especially when you first start taking it
• Stomach pain or cramping that usually improves over time
• Diarrhea, which often gets better as your body adjusts
• Constipation, particularly if you don't drink enough water
• Gas and bloating, which can be uncomfortable but typically mild
• Heartburn or indigestion after meals

These common side effects usually improve within a few weeks as your digestive system adapts to the medication. Drinking plenty of water and eating smaller, more frequent meals can help minimize discomfort.

Rare but more serious side effects can occur, though they affect very few people. These include severe constipation that could lead to bowel blockage, especially if you already have digestive problems. Some people might experience difficulty swallowing or severe stomach pain that doesn't improve.

Very rarely, sevelamer can cause a condition called metabolic acidosis, where your blood becomes too acidic. This is more likely with the hydrochloride form of the medication and usually shows up as unusual fatigue, confusion, or rapid breathing.

Who Should Not Take Sevelamer?

Sevelamer isn't suitable for everyone, and certain health conditions make it potentially dangerous. People with severe digestive problems should avoid this medication because it can worsen their symptoms.

You shouldn't take sevelamer if you have a bowel obstruction or severe constipation, as the medication could make these conditions worse. People with a history of major digestive surgery or inflammatory bowel disease need careful evaluation before starting this medication.

Those with swallowing difficulties should use caution, as the tablets can potentially cause choking or get stuck in the throat. If you have trouble swallowing pills, discuss alternative phosphate binders with your doctor.

Pregnant and breastfeeding women should only take sevelamer if the benefits clearly outweigh the risks. While the medication doesn't get absorbed into the bloodstream, it can affect the absorption of important vitamins and nutrients that both mother and baby need.

Sevelamer Brand Names

The most common brand name for sevelamer is Renagel, which contains sevelamer hydrochloride. Another widely available brand is Renvela, which contains sevelamer carbonate and is often preferred by doctors.

Generic versions of sevelamer are also available and work just as effectively as the brand-name versions. Your insurance may prefer the generic form, which can help reduce your medication costs significantly.

Both brand and generic versions require a prescription and come in different strengths. Your doctor will determine which form and strength work best for your specific situation.

Sevelamer Alternatives

Several other phosphate binders are available if sevelamer doesn't work well for you or causes too many side effects. Each alternative has its own benefits and considerations.

Calcium-based phosphate binders like calcium acetate or calcium carbonate are often tried first because they're less expensive. However, they can cause calcium buildup in your blood vessels, which makes them less suitable for long-term use.

Lanthanum carbonate is another non-calcium option that works similarly to sevelamer. It's typically well-tolerated but can be more expensive and may cause different side effects like stomach upset or metallic taste.

Iron-based phosphate binders like ferric citrate offer the added benefit of treating iron deficiency anemia, which is common in people with kidney disease. Your doctor can help determine which alternative might work best for your specific health needs.

Is Sevelamer Better Than Calcium Acetate?

Both sevelamer and calcium acetate effectively control phosphorus levels, but they work differently and have distinct advantages. The choice between them depends on your individual health situation and long-term treatment goals.

Sevelamer is generally considered better for long-term use because it doesn't add calcium to your system. This makes it safer for your blood vessels and heart, especially important considerations for people with kidney disease who are already at higher risk for cardiovascular problems.

Calcium acetate, on the other hand, is often more affordable and may be covered better by insurance. It can also help if you have low calcium levels, though this benefit becomes a drawback if your calcium levels are already normal or high.

Your doctor will consider factors like your calcium levels, heart health, cost concerns, and how well you tolerate each medication when making recommendations. Many people try calcium acetate first and switch to sevelamer if calcium levels become too high.