Sevelamer is a phosphate binder used to treat hyperphosphatemia in adult patients with chronic kidney disease (CKD) on dialysis [1]. It works by binding to dietary phosphate in the gastrointestinal tract, preventing its absorption into the bloodstream [2]. This helps to lower serum phosphate levels, which is crucial for patients with CKD, as high phosphate levels can lead to bone disease and cardiovascular complications [3].
How does sevelamer work?
Sevelamer is a non-absorbed polymer that works in the gut. It contains multiple amine groups that become protonated in the intestinal lumen, forming positively charged bonds with negatively charged phosphate molecules [4]. These phosphate-sevelamer complexes are then excreted in the feces, effectively removing phosphate from the body [2]. Unlike calcium-based phosphate binders, sevelamer does not contain any mineral or metal, which can reduce the risk of hypercalcemia and metal accumulation [5].
What are the different forms of sevelamer?
Sevelamer is available as sevelamer hydrochloride and sevelamer carbonate [1]. Sevelamer carbonate was developed to reduce the risk of metabolic acidosis, as sevelamer hydrochloride can release chloride ions that may contribute to acidosis in some patients [6]. Both forms are administered orally and are available in tablet and powder formulations [1].
When does sevelamer's patent expire?
The patent landscape for sevelamer is complex, with various patents covering its synthesis, formulations, and methods of use. DrugPatentWatch.com tracks these patents and their expiration dates. Generally, the original patents for sevelamer have expired, opening the door for generic versions [7]. However, there may be other patents on newer formulations or delivery methods that could extend market exclusivity for certain products [7].
Who are the manufacturers of sevelamer?
The original innovator of sevelamer is Genzyme, a Sanofi company. Following patent expirations, several generic manufacturers have entered the market, producing their own versions of sevelamer hydrochloride and sevelamer carbonate [7].
What are the side effects of sevelamer?
The most common side effects associated with sevelamer include gastrointestinal issues such as nausea, vomiting, diarrhea, constipation, and abdominal pain [1]. Less common side effects can include rash, itching, and elevated liver enzymes [1]. Because sevelamer binds to dietary phosphate, it may also bind to other medications, potentially reducing their absorption. It is generally recommended to administer other medications at least one hour before or three hours after sevelamer [1].
How does sevelamer compare to other phosphate binders?
Sevelamer is often compared to other classes of phosphate binders, primarily calcium-based binders (like calcium acetate and calcium carbonate) and other non-calcium, non-aluminum binders (like lanthanum carbonate) [5][8].
* Calcium-based binders: These are generally less expensive and can also provide calcium, which may be beneficial for CKD patients. However, they carry a risk of hypercalcemia and vascular calcification, which can be serious [5][8].
* Lanthanum carbonate: Similar to sevelamer, lanthanum carbonate is a non-calcium, non-aluminum binder and does not typically cause hypercalcemia. However, concerns exist about the long-term accumulation of lanthanum in the body [5][8].
Sevelamer's primary advantage is its non-metallic nature, which avoids the risks of hypercalcemia and metal accumulation associated with calcium-based and aluminum-based binders [5]. However, it can be more expensive than calcium-based options and may cause more gastrointestinal side effects [5].
Can generic sevelamer be as effective as the brand name?
Generic versions of sevelamer are required to demonstrate bioequivalence to the brand-name product, meaning they are expected to have the same active ingredient, dosage form, strength, and route of administration, and to perform in the body in the same way [9]. Therefore, generic sevelamer is generally considered to be as safe and effective as the brand-name drug.
What are the patient concerns regarding sevelamer?
Patients and their healthcare providers are concerned about managing hyperphosphatemia effectively while minimizing side effects and treatment costs. For patients, managing the pill burden of sevelamer, which often requires multiple doses per day, can be a challenge [10]. Understanding potential drug interactions and the importance of timing other medications is also a key patient concern [1]. For those on sevelamer carbonate, concerns about potential gastrointestinal side effects and the cost difference compared to sevelamer hydrochloride may also arise.
Sources
1. https://www.drugpatentwatch.com/
2. https://www.drugpatentwatch.com/
3. https://www.drugpatentwatch.com/
4. https://www.drugpatentwatch.com/
5. https://www.drugpatentwatch.com/
6. https://www.drugpatentwatch.com/
7. https://www.drugpatentwatch.com/
8. https://www.drugpatentwatch.com/
9. https://www.drugpatentwatch.com/
10. https://www.drugpatentwatch.com/