Potassium citrate

Description

Potassium citrate is a citrate salt of potassium with the empirical formula K₃C₆H₅O₇ • H₂O. It is characterized by its chemical structure and exists as transparent crystals or a white, granular powder. Potassium citrate is freely soluble in water and slightly soluble in alcohol.

The extended-release formulation of potassium citrate is available in tan to yellowish speckled oral wax-matrix tablets, which contain varying amounts of potassium citrate: 5 mEq (540 mg), 10 mEq (1080 mg), and 15 mEq (1620 mg), all provided as the monohydrate. Inactive ingredients in these tablets include carnauba wax and magnesium stearate. It is important to note that the FDA-approved dissolution specifications for potassium citrate differ from those established by the USP.

Uses and Indications

Potassium citrate extended-release tablets are indicated for the management of renal tubular acidosis (RTA) associated with calcium stones, hypocitraturic calcium oxalate nephrolithiasis of any etiology, and uric acid lithiasis, with or without the presence of calcium stones.

There are no teratogenic or nonteratogenic effects associated with the use of this medication.

Dosage and Administration

For patients with severe hypocitraturia (urinary citrate < 150 mg/day), therapy should be initiated at a dosage of 60 mEq per day. This can be administered as 30 mEq two times per day or 20 mEq three times per day. Doses should be taken with meals, within 30 minutes after meals, or at bedtime snack to enhance absorption.

In cases of mild to moderate hypocitraturia (urinary citrate > 150 mg/day), therapy should commence at a dosage of 30 mEq per day. This can be given as 15 mEq two times per day or 10 mEq three times per day, also with meals, within 30 minutes after meals, or at bedtime snack.

It is essential to adhere to these dosing schedules to optimize therapeutic outcomes and ensure patient safety.

Contraindications

Use of this product is contraindicated in the following situations:

Patients with hyperkalemia or conditions predisposing to hyperkalemia, including chronic renal failure, uncontrolled diabetes mellitus, acute dehydration, strenuous physical exercise in unconditioned individuals, adrenal insufficiency, and extensive tissue breakdown, due to the risk of exacerbating elevated potassium levels.

Patients with gastrointestinal conditions that may cause arrest or delay in tablet passage, such as delayed gastric emptying, esophageal compression, intestinal obstruction, or stricture, as these conditions may hinder proper absorption.

Patients with peptic ulcer disease, as the product may exacerbate gastrointestinal irritation.

Patients with an active urinary tract infection, due to the potential for worsening the infection.

Patients with renal insufficiency, specifically those with a glomerular filtration rate of less than 0.7 ml/kg/min, due to the risk of impaired drug clearance and potential toxicity.

Warnings and Precautions

Potassium citrate administration carries significant risks, particularly in patients with compromised renal function. Hyperkalemia is a critical concern, as it can occur in individuals with impaired mechanisms for potassium excretion. This condition may lead to cardiac arrest and can develop rapidly, often without symptoms. Therefore, the use of potassium citrate is contraindicated in patients with chronic renal failure or other conditions that hinder potassium excretion, such as severe myocardial damage or heart failure.

In addition to the risk of hyperkalemia, potassium citrate may also lead to gastrointestinal complications. In cases of severe vomiting, abdominal pain, or gastrointestinal bleeding, it is imperative to discontinue potassium citrate immediately. Healthcare professionals should consider the possibility of bowel perforation or obstruction in such scenarios and take appropriate investigative measures.

Monitoring of potassium levels is essential in patients receiving potassium citrate, particularly those with underlying renal issues or cardiovascular conditions. Regular assessment can help mitigate the risks associated with hyperkalemia and ensure patient safety.

Side Effects

Patients may experience a range of adverse reactions associated with potassium citrate administration. Common adverse reactions include minor gastrointestinal complaints such as abdominal discomfort, vomiting, diarrhea, loose bowel movements, and nausea.

Serious adverse reactions have been reported, including hyperkalemia, particularly in patients with impaired mechanisms for excreting potassium. This condition can lead to cardiac arrest and may develop rapidly and asymptomatically, posing a potentially fatal risk. In cases of severe vomiting, abdominal pain, or gastrointestinal bleeding, potassium citrate should be discontinued immediately, and the possibility of bowel perforation or obstruction should be investigated.

Additional considerations include patients with pre-existing hyperkalemia or conditions that predispose them to hyperkalemia, such as chronic renal failure, uncontrolled diabetes mellitus, acute dehydration, strenuous physical exercise in unconditioned individuals, adrenal insufficiency, and extensive tissue breakdown. Furthermore, caution is advised in patients who may experience delays in tablet passage through the gastrointestinal tract, including those with delayed gastric emptying, esophageal compression, intestinal obstruction, or stricture. Patients with peptic ulcer disease, active urinary tract infections, or renal insufficiency (with a glomerular filtration rate of less than 0.7 ml/kg/min) should also be closely monitored.

Drug Interactions

Concomitant administration of potassium-sparing diuretics is contraindicated due to the risk of severe hyperkalemia. It is advised to avoid the use of these agents together.

Drugs that slow gastrointestinal transit time, including anticholinergics, may exacerbate gastrointestinal irritation associated with potassium salts. Caution is recommended when these agents are used concurrently.

For patients receiving renin-angiotensin-aldosterone inhibitors, monitoring for hyperkalemia is essential. Regular assessment of potassium levels is advised to prevent potential complications.

Nonsteroidal anti-inflammatory drugs (NSAIDs) may also increase the risk of hyperkalemia. It is recommended to monitor potassium levels in patients taking NSAIDs alongside other medications that can affect potassium homeostasis.

Packaging & NDC

The table below lists all NDC Code configurations of Potassium-Cit, the U.S. brand-name prescription product. Columns show Packaging, Formulation Type, and Active Ingredient Strength.

Pediatric Use

Safety and effectiveness in pediatric patients have not been established. Therefore, the use of this medication in children is not recommended until further data are available to support its use in this population.

Geriatric Use

Elderly patients may exhibit altered pharmacokinetics and pharmacodynamics, necessitating caution when prescribing this medication. Although no specific geriatric use information is provided in the prescribing insert, it is important to consider the potential for reduced kidney function and increased sensitivity to side effects in this population.

Dosage adjustments may be required for elderly patients, particularly those with renal impairment or other comorbidities that could affect potassium excretion. Given that elderly patients may have impaired mechanisms for excreting potassium, there is an elevated risk of hyperkalemia and associated complications, such as cardiac arrest. Therefore, close monitoring for signs of hyperkalemia is strongly recommended.

In addition, periodic blood tests and electrocardiograms (ECGs) should be conducted to ensure the safety of elderly patients, especially those with pre-existing cardiac or renal conditions. These precautions are essential to mitigate risks and ensure appropriate management of this patient population.

Pregnancy

Pregnant patients should be aware that animal reproduction studies have not been conducted with potassium citrate. Therefore, it is not known whether potassium citrate can cause fetal harm when administered to a pregnant woman or if it can affect reproductive capacity. Given the lack of data, potassium citrate should be prescribed to pregnant women only if clearly needed, weighing the potential benefits against any unknown risks to fetal outcomes.

Lactation

Potassium citrate is not known to affect the normal potassium ion content of human milk, which is approximately 13 mEq/L. Due to the lack of data on its excretion in breast milk and potential effects on breastfed infants, potassium citrate should be administered to lactating mothers only if clearly needed.

Renal Impairment

Patients with impaired mechanisms for excreting potassium are at an increased risk of hyperkalemia when administered potassium citrate. This condition can lead to cardiac arrest and may develop rapidly, often without symptoms. Therefore, the use of potassium citrate is contraindicated in patients with chronic renal failure or any other conditions that significantly impair potassium excretion, such as severe myocardial damage or heart failure. Careful consideration and monitoring are essential in these populations to prevent potentially fatal outcomes.

Hepatic Impairment

There is no available information regarding the use of this medication in patients with hepatic impairment. Consequently, there are no dosage adjustments, special monitoring requirements, or precautions specified for individuals with compromised liver function. Healthcare professionals should exercise caution and consider the overall clinical context when prescribing this medication to patients with liver problems, as the absence of specific guidance necessitates careful evaluation of potential risks and benefits.

Overdosage

The administration of potassium salts in individuals without predisposing conditions for hyperkalemia is unlikely to result in serious hyperkalemia when dosages are kept within recommended limits. However, it is crucial to recognize that hyperkalemia often presents asymptomatically, typically indicated only by elevated serum potassium levels and specific electrocardiographic changes. These changes may include T-wave peaking, loss of the P-wave, S-T segment depression, and QT interval prolongation. In advanced cases, late manifestations can occur, such as muscle paralysis and cardiovascular collapse due to cardiac arrest.

Management of Hyperkalemia

In the event of hyperkalemia, several treatment measures should be implemented:

• Patients must be closely monitored for arrhythmias and electrolyte imbalances.

• It is essential to discontinue any medications that contain potassium or possess potassium-sparing properties. This includes potassium-sparing diuretics, angiotensin receptor blockers (ARBs), angiotensin-converting enzyme (ACE) inhibitors, nonsteroidal anti-inflammatory drugs (NSAIDs), and certain nutritional supplements.

• Dietary sources high in potassium should also be eliminated. Foods such as almonds, apricots, bananas, various beans (including lima, pinto, and white), cantaloupe, canned carrot juice, figs, grapefruit juice, halibut, milk, oat bran, potatoes (with skin), salmon, spinach, and tuna should be avoided.

For patients at low or no risk of developing digitalis toxicity, intravenous calcium gluconate may be administered. Additionally, intravenous administration of a 10% dextrose solution containing 10-20 units of crystalline insulin per 1,000 mL may be indicated, with a recommended infusion rate of 300-500 mL/hr. If acidosis is present, correction with intravenous sodium bicarbonate should be considered. In severe cases, hemodialysis or peritoneal dialysis may be necessary. While exchange resins can be utilized, they should not be relied upon as the sole treatment for acute hyperkalemia.

It is important to note that lowering potassium levels too rapidly in patients who are taking digitalis can precipitate digitalis toxicity. Furthermore, in patients with impaired potassium excretion mechanisms, such as those with chronic renal failure or severe myocardial damage, the administration of potassium citrate can lead to hyperkalemia and potentially fatal cardiac arrest. Therefore, the use of potassium citrate in these populations should be avoided.

Nonclinical Toxicology

Animal reproduction studies have not been conducted to evaluate the teratogenic potential of potassium citrate. Therefore, it is unknown whether potassium citrate can cause fetal harm when administered to a pregnant woman or if it can affect reproductive capacity. Potassium citrate should be administered to pregnant women only if clearly needed.

The normal potassium ion concentration in human milk is approximately 13 mEq/L. However, it is not known if potassium citrate influences this concentration. Consequently, potassium citrate should be given to breastfeeding women only if clearly needed.

Postmarketing Experience

No postmarketing experience details are available in the extracted data.

Patient Counseling

Patients should be advised to take each dose of the medication without crushing, chewing, or sucking the tablet to ensure proper absorption and effectiveness. It is crucial for patients to take this medicine only as directed, particularly if they are also using diuretics and digitalis preparations, as this can affect the medication's efficacy and safety.

Patients should be encouraged to communicate with their healthcare provider if they experience any difficulty swallowing the tablets or if they feel that the tablet is sticking in their throat. Additionally, patients must be instructed to seek immediate medical attention if they notice tarry stools or any other signs of gastrointestinal bleeding, as these may indicate serious side effects.

Healthcare providers should inform patients that regular blood tests and electrocardiograms will be performed by their doctor to monitor their safety while on this medication. This ongoing assessment is essential to ensure the patient's well-being and to make any necessary adjustments to their treatment plan.

Storage and Handling

The product is supplied in a tight container to ensure integrity and stability. It must be stored at a temperature range of 20° to 25°C (68° to 77°F), in accordance with USP Controlled Room Temperature guidelines. It is essential to dispense the product in this container without repackaging to maintain its quality and efficacy.

Additional Clinical Information

No further data are available.

FDA Insert (PDF)

This document is the official FDA-approved prescribing information for Potassium-Cit as submitted by Eywa Pharma Inc. It includes detailed information about indications, dosage, contraindications, warnings, and clinical pharmacology.

View full prescribing information (PDF)