Renagel

Renagel is a drug used for hyperphosphatemia and -kalemia. It contains polyallylamine hydrochloride (a phosphate-binding polymer) and sevelamer; the drug is not absorbed and does not contain calcium or metals. Instead, it contains polyamines that are separated from the main polymer chain by carbon molecules. Some of these amines are protonated in the intestine and also interact with phosphate molecules through hydrogen and ionic bonds.

The synthesis of phosphate within the gastrointestinal tract by sevelamer results in a decrease in serum phosphate levels.

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Indications Renagel

It is used for hyperphosphatemia in individuals undergoing peritoneal dialysis or hemodialysis sessions.

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Release form

The medicinal element is released in tablets - 180 pieces in a polyethylene jar.

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Pharmacodynamics

Clinical trials have examined the effectiveness of the sevelamer component in reducing serum phosphorus levels in people undergoing peritoneal dialysis or hemodialysis.

Sevelamer reduces the incidence of hypercalcemia compared to Ca-based phosphate binders (probably because it does not contain calcium). Testing over 12 months has shown that the drug's effect on Ca-phosphate levels is maintained for at least that period.

The component is capable of synthesizing bile acids both in vitro and in vivo during studies on experimental animal models. Synthesis of bile acids occurs using ion-exchange resins (a method used to reduce blood cholesterol levels). In clinical tests, sevelamer led to a 15-31% decrease in LDL and total cholesterol levels. This effect was noted after 14 days of therapy and persisted with prolonged treatment. Albumin and triglyceride levels with HDL cholesterol remained the same.

In clinical trials in subjects undergoing hemodialysis, sevelamer alone had no effect on serum intact parathyroid hormone levels. In a 3-month trial in subjects undergoing peritoneal dialysis, the effect was reduced intact parathyroid hormone levels compared to subjects using calcium acetate.

During therapy in patients with secondary hyperparathyroidism, Renagel is used in combination with other medications, including calcium drugs and D3 1,25-dihydroxyvitamin or one of its analogues. This is necessary to reduce the intact parathyroid hormone levels.

A 12-month clinical trial showed that the drug did not cause any negative effects on mineralization or bone mass (compared to Ca carbonate).

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Dosing and administration

The medication is administered in combination with other medications – this is necessary to prevent the occurrence of renal osteodystrophy.

Renagel is taken orally, with food - the tablets do not need to be chewed, they are swallowed whole. It is also necessary to follow the diet prescribed by the doctor.

At first, it is recommended to take 2.4 or 4.8 g of the substance per day (when selecting a portion, clinical needs and phosphorus levels in the blood serum are taken into account). The medicine is used 3 times a day, with food.

For serum phosphate values (in individuals not using phosphate-binding drugs) of 1.76-2.42 mmol/L (or 5.5-7.5 mg/dL), 1 tablet of 0.8 g should be taken 3 times a day. If the indicated values are >2.42 mmol/L (or >7.5 mg/dL), 2 such tablets should be taken 3 times a day.

For people previously using phosphate binders, the medication is administered in a g/g (equal proportions) ratio, while monitoring serum phosphorus levels to ensure that the optimal daily dose is being used.

Serum phosphate levels should be monitored continuously and the drug dosage adjusted to reduce the level to 1.76 mmol/L (or 5.5 mg/dL) or less. Serum phosphate levels are initially checked at 2-3 week intervals (until a stable level is achieved), and then regularly.

Servings may vary between 1-5 tablets per meal. In clinical trials lasting 12 months, during the chronic stage, the average daily dosage of sevelamer was 7 g.

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Use Renagel during pregnancy

There is no information regarding the safety of using the drug during pregnancy. Animal tests have not revealed the development of embryotoxicity when sevelamer is administered. Renagel is used in pregnant women only if there are strict indications and after careful assessment of the risk-benefit ratio.

The safety of using the drug during lactation has also not been studied. Therefore, it is used during this period only after assessing the possible consequences and benefits, according to vital indications.

Contraindications

Main contraindications:

• severe intolerance associated with sevelamer or other components of the drug;
• hypophosphatemia;
• intestinal obstruction.

Side effects Renagel

Among the side symptoms associated with the work of the digestive organs: vomiting or nausea mainly appears. Also often observed is bloating, constipation, dyspepsia, diarrhea or pain in the upper abdominal area.

During the post-marketing period, the occurrence of rash, pruritus, intestinal obstruction, abdominal pain, intestinal perforation or obstruction (complete or partial) has been reported.

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Interactions with other drugs

In interaction tests involving volunteers, the drug reduced the bioavailability of ciprofloxacin by approximately 50%. The study of this combination was conducted with the administration of a single dose. Therefore, the drug is prohibited for use together with ciprofloxacin.

In the post-marketing period, TSH values have been occasionally increased in people who combined the drug with levothyroxine. Therefore, it is necessary to carefully monitor TSH values in people who take these drugs together.

In organ transplant recipients, when Renagel was co-administered with mycophenolate mofetil, cyclosporine and tacrolimus, there was a decrease in the levels of these drugs, but without clinical complications (e.g., rejection of the transplanted organ). The possibility of interaction cannot be excluded, so blood levels of these drugs should be closely monitored during co-administration and after discontinuation of their use.

When using any medication for which a decrease in bioavailability may have a clinical impact on efficacy and safety, such a drug must be taken at least 60 minutes before or 3 hours after using Renagel. Otherwise, the doctor must monitor blood levels of such drugs.

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Storage conditions

Renagel should be stored out of the reach of small children. Temperature readings are a maximum of 25ºC.

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Shelf life

Renagel is approved for use for a period of 36 months from the date of sale of the drug.

Application for children

The therapeutic efficacy and safety of the drug in pediatrics have not been studied, which is why Renagel is not prescribed to this category of patients.

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Analogues

Analogues of the drug are Renvela, Calcium Acetate, as well as Selamerex with Sevelamer.

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