SEVCAR 800

Mechanism of action

Carbonate ions participate in buffering reactions that help maintain pH homeostasis in biological systems. They can react with acids to form bicarbonate and carbon dioxide, thus neutralizing excess acidity in the body. This mechanism is crucial in processes such as respiration and metabolism.

Pharmacodynamics

As a buffer, carbonate helps to stabilize pH levels in different biological environments, preventing excessive acidity or alkalinity that could impair cellular functions. It is involved in the transport of carbon dioxide in the blood and plays a role in maintaining the acid-base equilibrium necessary for physiological processes.

Pharmacokinetics

Carbonate ions are readily absorbed in the gastrointestinal tract when ingested and can be found in various body fluids. They are involved in the bicarbonate buffering system, where they are converted to bicarbonate (HCO3-) and carbon dioxide (CO2) through reactions with acids. The kidneys regulate the levels of bicarbonate and carbonate in the body, excreting or reabsorbing them as needed to maintain homeostasis.

Pregnancy

There is no specific information available regarding the use of carbonate compounds during pregnancy. Consult a healthcare provider for advice.

Breast-feeding

There is no specific information available regarding the use of carbonate compounds while breastfeeding. Consult a healthcare provider for advice.

Storage

Store in a cool, dry place away from direct sunlight. Keep out of reach of children.

Indications

• Hyperphosphataemia in patients on haemodialysis
• Hyperphosphataemia in patients on peritoneal dialysis
• Hyperphosphataemia in patients with chronic kidney disease not on dialysis who have elevated serum phosphate levels

Dosage

Children: Dose to be adjusted according to the requirements of the patient, taken with meals. Consult product literature for specific dosing information.

Adults: Initially 2.4–4.8 g daily in 3 divided doses, to be taken with meals and adjusted according to serum-phosphate concentration every 2–4 weeks. The usual maintenance dose is 6 g daily in 3 divided doses.

Mechanism of action

Sevelamer works by binding phosphate in the gastrointestinal tract, preventing its absorption into the bloodstream. This mechanism is crucial for patients with renal impairment who cannot adequately excrete phosphate, leading to hyperphosphataemia. By reducing intestinal phosphate absorption, sevelamer helps in maintaining normal serum phosphate levels.

Pharmacodynamics

Sevelamer's phosphate-binding ability helps to lower serum phosphate levels, which is vital in patients with chronic kidney disease. Elevated serum phosphate can lead to cardiovascular complications and bone mineral disorders. The pharmacodynamic profile of sevelamer indicates a dose-dependent effect on serum phosphate reduction, which is monitored and adjusted based on individual patient needs.

Pharmacokinetics

Sevelamer is not absorbed systemically; it remains in the gastrointestinal lumen where it binds phosphate. The pharmacokinetic properties indicate that peak phosphate-binding occurs shortly after administration, particularly when taken with meals. The elimination of sevelamer is primarily through feces, as it does not undergo significant metabolic transformation or systemic absorption.

Contra-indications

• haemochromatosis
• iron accumulation disorders
• bowel obstruction

Adverse effects

• constipation
• diarrhoea
• gastrointestinal discomfort
• nausea
• vomiting
• abnormal taste
• tooth discolouration

Interactions

• calcium salts
• iron
• roxadustat (modestly decreases exposure)

Precautions

• gastrointestinal disorders
• hepatic disorders
• major surgery
• peritonitis in the last 3 months

Pregnancy

Manufacturer advises use only if potential benefit outweighs risk.

Breast-feeding

Unlikely to be present in milk, however, manufacturer advises to avoid.

Storage

Store at room temperature, away from moisture and heat.

Formulations

• {'name': 'Renvela', 'form': 'oral powder sachets', 'strength': '2.4 g', 'pack_size': '60 sachets'}
• {'name': 'Renvela', 'form': 'chewable tablets', 'strength': '800 mg', 'pack_size': '90 tablets'}