Common questions about Renvela (FAQ)
Q: Does Renvela reduce the effectiveness of levothyroxine (thyroid hormone replacement)?
A: Official reports indicate a risk of increased Thyroid Stimulating Hormone (TSH) when these medicines are taken together. Because of this, closer monitoring of TSH levels may be required when Renvela and levothyroxine are co-administered.
Q: Is it necessary to separate Renvela from immune-suppressing drugs like mycophenolate?
A: Yes, the official labeling provides specific dosing recommendations for separating the administration time of Renvela from certain immunosuppressants, such as mycophenolate mofetil. This timing requirement is in place to mitigate the risk of reduced absorption and effectiveness of the immunosuppressant medication.
Q: Is Renvela safe for use in children with high phosphorus levels?
A: Safety and effectiveness for controlling serum phosphorus levels have been established in children with chronic kidney disease (CKD) who are 6 years of age and older. Dosage is determined based on the patient's body surface area (BSA).
Q: Why is regular blood work necessary when a person is on Renvela therapy?
A: The official guidance includes the recommendation for regular monitoring of blood chemistries, including serum phosphorus, chloride, and bicarbonate. Monitoring is also advised for levels of fat-soluble vitamins (A, D, E, K) and folic acid, as long-term use may affect their absorption.
Q: What is the difference between Renvela (sevelamer carbonate) and Renagel (sevelamer hydrochloride)?
A: Both products contain the same active component, sevelamer, but they use different salt forms: Renvela is a carbonate salt, and Renagel is a hydrochloride salt. This difference is related to their potential influence on the body’s acid-base balance, specifically serum bicarbonate levels.
Q: Is Renvela a calcium-free phosphate binder?
A: Yes, official regulatory documents describe sevelamer carbonate (Renvela) as a phosphate-binding agent that is both calcium-free and metal-free.
Q: How quickly can a person expect their serum phosphorus levels to change after starting Renvela?
A: Clinical evidence indicates that a reduction in serum phosphorus levels has been observed in studies to occur within approximately one to two weeks after treatment is initiated.
Q: Is Renvela intended to treat the underlying kidney disease itself?
A: No, the official indication for Renvela is specifically for the control of elevated serum phosphorus in patients with chronic kidney disease (CKD). It is not indicated as a treatment for the underlying kidney disease itself.
Q: Are gastrointestinal side effects like gas, bloating, and indigestion common with Renvela?
A: Yes, official product information indicates that gastrointestinal issues are among the most commonly reported side effects. These include vomiting, nausea, dyspepsia (indigestion), abdominal pain, flatulence (gas), and constipation.
Q: Does Renvela typically cause constipation or diarrhea?
A: Both constipation and diarrhea are listed as reported adverse reactions. In clinical studies, diarrhea, nausea, and vomiting were among the frequently reported adverse events.
Q: What are the signs of a serious bowel problem related to Renvela use?
A: Serious gastrointestinal events, including bowel obstruction and perforation, have been reported with sevelamer use. If severe constipation or other severe gastrointestinal symptoms occur, it is important to seek immediate attention from a healthcare provider.
Q: Is difficulty swallowing a reported concern with the Renvela tablet formulation?
A: Yes, official warnings note that cases of difficulty swallowing (dysphagia) and esophageal tablet retention have been reported with the tablet formulation. Official guidance suggests the powder for oral suspension may be considered for patients with a history of swallowing disorders.
Q: Can Renvela be used if a person has a history of bowel obstruction?
A: No, according to the official regulatory documents, Renvela is contraindicated, meaning it should not be used, in patients who have a known bowel obstruction.
Q: What is hypophosphatemia, and why is it listed as a contraindication for Renvela?
A: Hypophosphatemia means having abnormally low serum phosphate levels. Because Renvela is designed to lower phosphate levels, this condition is listed as a contraindication in some regulatory jurisdictions to limit the risk of exacerbating low phosphorus levels.
Q: What is known about taking Renvela during pregnancy?
A: Renvela is not absorbed systemically by the mother following oral administration. However, because the drug can decrease the absorption of fat-soluble vitamins and folic acid, official documents suggest that vitamin supplementation may be considered.
Q: What information is available regarding Renvela use while breastfeeding?
A: Since Renvela is not absorbed systemically by the mother, breastfeeding is not expected to result in exposure of the child to the drug.
Q: Can the powder formulation of Renvela be mixed with hot food or beverages?
A: The official preparation instructions only specify mixing the powder with a minimum amount of water and consuming it within 30 minutes of preparation. No information is provided in the labeling regarding mixing the powder with hot food or hot beverages.
Q: Is it possible for a patient's phosphate levels to increase even while taking Renvela?
A: Official dosing guidelines state that the dose is adjusted (titrated) based on the patient's observed serum phosphorus levels. This indicates that levels are monitored and the dose may need to be managed if levels remain elevated or rise.
Q: What are the general expectations for the long-term use of Renvela?
A: Renvela is often used for the long-term management of serum phosphorus levels in chronic kidney disease patients. Continuous, long-term use requires periodic monitoring of blood chemistries and fat-soluble vitamin levels to ensure the treatment remains effective and safe.
Q: What is the significance of the warning about intestinal perforation with sevelamer?
A: The warning is significant because serious cases of intestinal perforation (a hole in the intestine) have been associated with sevelamer use. Some of these cases have required hospitalization and surgery.
Q: Can taking Renvela cause issues with stomach ulcers or bleeding?
A: Official post-marketing reports have indicated cases of serious gastrointestinal issues, including bleeding gastrointestinal ulcers, colitis, ulceration, and necrosis, associated with sevelamer use.
Q: Does Renvela affect how calcium supplements are absorbed?
A: Renvela is a calcium-free phosphate binder whose mechanism of action primarily involves binding phosphate in the gut. Unlike some other phosphate binders, it has not been shown in studies to alter serum calcium concentrations.
Q: What are the restrictions on using Renvela if a patient has had recent gastrointestinal surgery?
A: Regulatory information notes that patients with a history of major gastrointestinal tract surgery were generally excluded from the clinical studies. Caution is advised for its use in patients with severe gastrointestinal motility disorders.
Q: Can Renvela affect a person's bicarbonate levels?
A: Renvela is the carbonate salt form of sevelamer, which was developed to help minimize the potential for acidosis (low bicarbonate) that has been associated with the hydrochloride salt form. Monitoring of serum chemistries, including bicarbonate, is recommended during treatment.
Q: What are the common symptoms of a possible allergic reaction to Renvela?
A: Hypersensitivity (an allergic reaction) is listed as a post-marketing adverse reaction. Renvela is officially contraindicated in patients with known hypersensitivity to its active ingredient, sevelamer carbonate, or any of its excipients.
Q: Why is severe constipation a reason to contact a healthcare provider immediately while taking Renvela?
A: Severe constipation is a reported concern because it may be a preceding symptom of a more serious gastrointestinal issue, such as bowel obstruction or ileus, which has been reported with sevelamer use.
Q: Is it generally safe for older adults to take Renvela?
A: Official studies have been conducted that included geriatric patients. These studies have not demonstrated problems specific to older adults that would limit its use.
Q: What research evidence supports the use of Renvela in patients with CKD on dialysis?
A: The official clinical studies section indicates that trials have been conducted to support the use of Renvela for controlling serum phosphorus levels in adult patients with chronic kidney disease on hemodialysis and peritoneal dialysis.
