Cinacalcet Glenmark

What Is Cinacalcet Glenmark and What Is It Used For?

Cinacalcet Glenmark is a calcimimetic medicine containing cinacalcet hydrochloride. It is used to treat secondary hyperparathyroidism (SHPT) in adults with chronic kidney disease (CKD) on dialysis, to reduce hypercalcemia in adults with parathyroid carcinoma, and to reduce hypercalcemia in adults with primary hyperparathyroidism where parathyroidectomy is not clinically appropriate or is contraindicated.

Cinacalcet belongs to the pharmacological class of calcimimetic agents. It works by directly acting on the calcium-sensing receptor (CaSR) located on the surface of parathyroid gland cells. By increasing the sensitivity of these receptors to extracellular calcium, cinacalcet effectively signals the parathyroid glands to reduce their output of parathyroid hormone (PTH). This mechanism of action is fundamentally different from vitamin D analogues or phosphate binders, which also play a role in managing mineral metabolism disorders in kidney disease.

The parathyroid glands are four small glands located behind the thyroid gland in the neck. They produce PTH, a hormone that plays a central role in calcium homeostasis. In patients with chronic kidney disease, particularly those on haemodialysis or peritoneal dialysis, the parathyroid glands often become overactive, producing excessive amounts of PTH. This condition, known as secondary hyperparathyroidism, leads to elevated calcium and phosphate levels in the blood, which over time can cause significant damage to bones, blood vessels, and the heart. Cinacalcet helps to interrupt this pathological cycle by reducing PTH secretion at the source.

In the context of parathyroid carcinoma, a rare but serious malignancy of the parathyroid glands, cinacalcet is used to manage the severe hypercalcemia that often accompanies this condition. Parathyroid carcinoma causes uncontrolled PTH release, leading to dangerously elevated calcium levels that can result in kidney stones, bone loss, cardiac arrhythmias, and neurological symptoms. Cinacalcet provides a medical means of controlling calcium levels when surgical removal of the cancer is not possible or when hypercalcemia recurs after surgery.

For patients with primary hyperparathyroidism, where one or more parathyroid glands are overactive (usually due to a benign adenoma), parathyroidectomy (surgical removal of the affected gland) is the standard treatment. However, in patients who cannot undergo surgery due to comorbidities, high surgical risk, or personal preference, cinacalcet offers an effective non-surgical alternative for lowering serum calcium levels. Clinical trials have demonstrated that cinacalcet can normalize calcium levels in a significant proportion of these patients, improving symptoms and reducing the long-term complications of sustained hypercalcemia.

What Should You Know Before Taking Cinacalcet Glenmark?

Before starting Cinacalcet Glenmark, your doctor must check your serum calcium level. Do not take this medicine if your calcium is below the lower limit of normal. Inform your doctor about all other medicines you take, as cinacalcet can interact with several commonly prescribed drugs.

Contraindications

Cinacalcet Glenmark must not be taken if you are allergic (hypersensitive) to cinacalcet or any of the excipients in the tablet. You should not start cinacalcet therapy if your serum calcium level (corrected for albumin) is below the lower limit of the normal range. This is because cinacalcet will further lower calcium levels, potentially causing symptomatic or severe hypocalcemia, which can be dangerous.

Your doctor should verify that your calcium levels are adequate before prescribing this medicine. If you have previously experienced a severe allergic reaction to cinacalcet, you should not be re-exposed to the drug. Although rare, hypersensitivity reactions including rash, urticaria, and angioedema have been reported with cinacalcet use.

Warnings and Precautions

The most important safety concern with cinacalcet is the risk of hypocalcemia (low blood calcium). This risk is particularly relevant at the start of treatment and after dose adjustments. Symptoms of hypocalcemia include paraesthesia (tingling or numbness in the fingertips, toes, or around the mouth), myalgia (muscle pain), muscle cramps, and in severe cases, tetany (sustained muscle contractions) and seizures. If you experience any of these symptoms, contact your healthcare provider immediately.

Seizures have been reported in clinical trials and post-marketing surveillance in patients taking cinacalcet, both in the setting of significantly reduced serum calcium levels and in patients with a history of seizure disorders. If you have a pre-existing seizure disorder, your doctor should weigh the benefits and risks of cinacalcet carefully and monitor you closely during treatment. The threshold for seizures may be lowered by reduced serum calcium levels.

Patients with hepatic impairment should be monitored closely. Cinacalcet is extensively metabolized by the liver, primarily through the cytochrome P450 enzymes CYP3A4, CYP2D6, and CYP1A2. Patients with moderate to severe hepatic impairment may have higher circulating levels of cinacalcet, which can increase the risk of adverse effects. Dose adjustments may be required based on clinical response and tolerability.

Cinacalcet should be used with caution in patients with heart failure, as reductions in serum calcium can affect cardiac function. Hypocalcemia can prolong the QT interval, potentially leading to cardiac arrhythmias. If you have a history of QT prolongation, heart failure, or are taking medications known to prolong the QT interval, your doctor should monitor your cardiac function and electrolyte levels closely.

Adynamic bone disease may develop if PTH levels are chronically suppressed below the recommended target range. If PTH falls below the recommended range during treatment, the dose of cinacalcet and/or vitamin D analogues should be reduced or therapy discontinued. Regular monitoring of PTH levels, typically every 1 to 3 months, is essential to avoid oversuppression.

Pregnancy and Breastfeeding

There are no or limited data on the use of cinacalcet in pregnant women. Animal studies have shown reproductive toxicity at high doses. Cinacalcet should not be used during pregnancy unless the clinical condition of the woman requires treatment with cinacalcet and the potential benefit justifies the potential risk to the foetus. If you become pregnant while taking this medicine, inform your doctor as soon as possible so that the treatment plan can be reassessed.

It is not known whether cinacalcet or its metabolites are excreted in human breast milk. Studies in lactating rats have shown that cinacalcet is secreted in milk. A decision must be made whether to discontinue breastfeeding or to discontinue cinacalcet therapy, taking into account the benefit of breastfeeding for the child and the benefit of therapy for the mother. Discuss this with your doctor if you are breastfeeding or plan to breastfeed.

How Does Cinacalcet Glenmark Interact with Other Drugs?

Cinacalcet is metabolized by cytochrome P450 enzymes and is itself a strong inhibitor of CYP2D6. This means it can interact with drugs that are metabolized by CYP2D6 (increasing their blood levels) and drugs that inhibit or induce CYP3A4 (which alter cinacalcet's own blood levels). Always tell your doctor about all medicines, supplements, and herbal products you are taking.

Understanding cinacalcet's drug interactions is essential for safe and effective therapy. Cinacalcet is primarily metabolized by the hepatic cytochrome P450 enzymes CYP3A4, CYP2D6, and CYP1A2. It is also a potent inhibitor of CYP2D6, meaning it can significantly increase the plasma concentrations of drugs that are primarily metabolized by this enzyme. This creates two important categories of interactions: drugs that affect cinacalcet levels, and drugs whose levels are affected by cinacalcet.

Major Interactions

Strong CYP3A4 inhibitors such as ketoconazole, itraconazole, and voriconazole can substantially increase cinacalcet exposure. In a pharmacokinetic study, co-administration of ketoconazole 200 mg twice daily increased cinacalcet AUC by approximately 2-fold. If concurrent use with strong CYP3A4 inhibitors is unavoidable, the dose of cinacalcet may need to be reduced, and serum calcium and PTH levels should be monitored more frequently.

Cinacalcet is a potent inhibitor of CYP2D6. Drugs with a narrow therapeutic index that are metabolized by CYP2D6 require careful dose adjustment when used with cinacalcet. Flecainide and thioridazine are examples of medications with narrow therapeutic indices that should be used with particular caution, as elevated plasma levels can lead to serious adverse effects, including cardiac arrhythmias or central nervous system toxicity.

Minor Interactions

Cinacalcet has been shown to not significantly interact with warfarin, midazolam (a CYP3A4 substrate used as a probe drug), or pantoprazole (a proton pump inhibitor). Calcium-based phosphate binders and vitamin D analogues can be used concomitantly with cinacalcet, but the dose of calcium supplements or calcium-based phosphate binders may need adjustment based on calcium monitoring results. Dialysis patients often take multiple medications, so a thorough review of all drug therapy is recommended at every visit.

Smoking may affect cinacalcet levels, as polycyclic aromatic hydrocarbons in cigarette smoke are known inducers of CYP1A2. Patients who start or stop smoking during cinacalcet therapy may experience changes in drug levels. Grapefruit juice is a known CYP3A4 inhibitor and may modestly increase cinacalcet exposure; however, the clinical significance of this interaction has not been formally studied. As a precautionary measure, patients may wish to avoid regular consumption of large quantities of grapefruit juice while on cinacalcet.

What Is the Correct Dosage of Cinacalcet Glenmark?

The starting dose varies by indication. For secondary hyperparathyroidism on dialysis, the usual starting dose is 30 mg once daily, taken with food. Doses are titrated every 2-4 weeks based on PTH and calcium levels, up to a maximum of 180 mg once daily. For parathyroid carcinoma and primary hyperparathyroidism, the starting dose is also 30 mg twice daily, titrated to a maximum of 90 mg three to four times daily.

Adults

The dosage of cinacalcet must be individualized for each patient based on their specific clinical indication, biochemical parameters, and treatment response. The tablets should be swallowed whole with water and taken with food or shortly after a meal to optimize absorption. Do not break, crush, or chew the tablets, as this may affect the drug release profile and increase the risk of gastrointestinal side effects.

For secondary hyperparathyroidism in dialysis patients, the target is to achieve a PTH level within the recommended range as defined by the KDIGO guidelines (generally 2-9 times the upper limit of normal for the assay used). The dose should not be increased more frequently than every 2-4 weeks. After each dose adjustment, serum calcium should be measured within 1 week, and PTH should be measured after at least 4 weeks at the new dose to assess whether the response is adequate.

For parathyroid carcinoma and primary hyperparathyroidism, the primary goal is to normalize or reduce serum calcium levels. The dose is titrated upward in increments of 30 mg twice daily approximately every 2-4 weeks as needed. It is essential that calcium levels be monitored closely throughout treatment, particularly after dose changes, to avoid overshooting the target and causing hypocalcemia.

Children

Cinacalcet Glenmark is not recommended for use in children and adolescents under 18 years of age. The safety and efficacy of cinacalcet in paediatric patients have not been established in adequate and well-controlled clinical trials. The EMA and FDA have not approved cinacalcet for use in this age group. In children with CKD on dialysis who develop secondary hyperparathyroidism, other treatment strategies including dietary phosphate restriction, phosphate binders, and active vitamin D analogues are generally preferred as first-line options. Paediatric nephrologists should be consulted for management of refractory hyperparathyroidism in children.

Elderly

No overall differences in safety or efficacy have been observed between elderly patients (65 years and older) and younger patients in clinical trials of cinacalcet. However, elderly patients are more likely to have reduced hepatic function, renal impairment, and to be taking multiple medications, all of which can affect cinacalcet pharmacokinetics and increase the risk of adverse effects. No specific dose adjustment is required based on age alone, but careful monitoring and a cautious approach to dose titration are recommended in elderly patients.

Missed Dose

If you miss a dose of Cinacalcet Glenmark, take it as soon as you remember, provided it is still within a few hours of the scheduled time and you are able to take it with food. If it is close to the time of your next dose, skip the missed dose and resume your regular dosing schedule. Do not take a double dose to make up for a forgotten dose. If you frequently forget doses, speak with your healthcare provider about strategies to improve adherence, as consistent dosing is important for maintaining stable PTH and calcium levels.

Overdose

In the event of an overdose, symptoms related to hypocalcemia would be expected. These may include severe numbness, tingling, muscle spasms, tetany, cardiac arrhythmias (especially QT prolongation), and seizures. Overdose with cinacalcet requires immediate medical attention. Treatment is supportive and may include intravenous calcium gluconate to rapidly correct severe hypocalcemia. Since cinacalcet is highly protein-bound (approximately 93-97%), it is not expected to be efficiently removed by haemodialysis. Continuous cardiac monitoring and correction of electrolyte imbalances are essential in the management of a cinacalcet overdose.

What Are the Side Effects of Cinacalcet Glenmark?

The most common side effects of cinacalcet include nausea (very common, affecting more than 1 in 10 patients), vomiting, reduced appetite, dizziness, paraesthesia (tingling/numbness), and muscle spasms. Most gastrointestinal side effects occur early in treatment and may improve over time. Hypocalcemia is a pharmacologically expected and clinically significant adverse effect that requires monitoring.

Like all medicines, cinacalcet can cause side effects, although not everybody gets them. The side effects listed below are based on data from clinical trials and post-marketing surveillance reports. They are classified according to their frequency of occurrence, using the standard medical convention. If you experience any side effects not listed here, or if any side effects become severe, inform your doctor or pharmacist.

The gastrointestinal side effects of cinacalcet, particularly nausea and vomiting, are among the most frequently reported reasons for treatment discontinuation. These symptoms tend to be most pronounced during the initial weeks of therapy or following dose increases. Taking cinacalcet with food can help to mitigate nausea. If gastrointestinal symptoms persist, your doctor may recommend temporarily reducing the dose or using antiemetic medications as supportive treatment.

Hypocalcemia deserves special attention as a side effect. While it is a pharmacologically predictable consequence of cinacalcet's mechanism of action, it can have serious clinical consequences if not detected and managed promptly. In clinical trials, approximately 5% of patients with secondary hyperparathyroidism on dialysis developed serum calcium levels below 7.5 mg/dL (1.88 mmol/L). The risk of hypocalcemia is highest during the first months of treatment and following dose increases. Adequate calcium and vitamin D supplementation, combined with close monitoring, can help to minimize this risk.

Post-marketing surveillance has identified rare cases of isolated and idiosyncratic reactions to cinacalcet, including upper gastrointestinal bleeding in dialysis patients. While a causal relationship has not been definitively established, patients with known risk factors for gastrointestinal bleeding (such as concomitant use of non-steroidal anti-inflammatory drugs or anticoagulants) should be monitored with additional care. If you notice any unusual symptoms, including signs of gastrointestinal bleeding such as dark stools, vomiting blood, or persistent abdominal pain, seek medical attention immediately.

How Should You Store Cinacalcet Glenmark?

Store Cinacalcet Glenmark at room temperature (below 25°C / 77°F) in the original packaging to protect from moisture and light. Keep out of the sight and reach of children. Do not use after the expiry date printed on the packaging.

Proper storage of medications is essential to ensure their safety and efficacy. Cinacalcet Glenmark film-coated tablets should be stored at a temperature not exceeding 25°C (77°F). Keep the tablets in the original blister packaging until ready to use, as this provides protection from moisture and light, both of which can degrade the active ingredient over time. Do not transfer the tablets to a different container unless it provides equivalent protection.

Keep this medicine out of the sight and reach of children. Accidental ingestion of cinacalcet by a child could cause serious hypocalcemia requiring emergency treatment. Store the medicine in a secure location, ideally in a locked cabinet or a location not accessible to children.

Do not use this medicine after the expiry date which is stated on the carton and blister packaging after "EXP". The expiry date refers to the last day of that month. Do not throw away any medicines via wastewater or household waste. Ask your pharmacist how to dispose of medicines you no longer use. These measures will help protect the environment and prevent accidental exposure to others.

If you notice any visible changes in the appearance of the tablets, such as discolouration, crumbling, or an unusual odour, do not take them. Instead, return the affected tablets to your pharmacist for proper disposal and obtain a fresh supply. During travel, keep the medicine in your carry-on luggage in its original packaging, and avoid exposing it to extreme temperatures (such as leaving it in a hot car or in direct sunlight).

What Does Cinacalcet Glenmark Contain?

Each Cinacalcet Glenmark 30 mg film-coated tablet contains 30 mg of cinacalcet (as cinacalcet hydrochloride) as the active substance. The tablet also contains inactive excipients that serve as fillers, binders, and coating agents to facilitate manufacturing, stability, and administration.

The active substance in each tablet is cinacalcet hydrochloride, equivalent to 30 mg of cinacalcet. Cinacalcet hydrochloride is a white to off-white crystalline powder that is sparingly soluble in water. The molecular formula is C₂₂H₂₂F₃N·HCl, and the molecular weight is approximately 393.9 g/mol. The drug exerts its pharmacological effect through allosteric modulation of the calcium-sensing receptor.

The tablet core typically contains inactive ingredients (excipients) such as microcrystalline cellulose (a commonly used filler and binder), povidone (a binding agent), crospovidone (a disintegrant that helps the tablet dissolve in the gastrointestinal tract), magnesium stearate (a lubricant used during manufacturing), and colloidal silicon dioxide (a glidant). The film coating usually contains a mixture of hypromellose, titanium dioxide, triacetin, and iron oxide pigments, which provide the tablet with its distinctive appearance and protect the core from moisture.

For patients with known allergies or intolerances to specific excipients, the full list of excipients can be found in the patient information leaflet included with the medicine or by consulting your pharmacist. Patients with lactose intolerance should verify whether their specific product formulation contains lactose, as this can vary between manufacturers and formulations. The film-coated tablets are designed to be swallowed whole and should not be crushed or divided.

Frequently Asked Questions About Cinacalcet Glenmark

References and Sources

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