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elcys

Elcys (Cysteine Hydrochloride) is a medication supplied as an injection, solution.

Cysteine Hydrochloride · by Exela Pharma

Not yet rated· sourced from the FDA label
Rated against independent regulatory sources·Last updated June 7, 2026·How we rate
Verified againstopenFDANIH DailyMedRxClass

Key facts

Active ingredient
Cysteine Hydrochloride
Form
Injectable
Strength
Cysteine Hydrochloride 2500MG/50ML (50MG/ML) · Cysteine Hydrochloride 500MG/10ML (50MG/ML)
Type
Prescription (Rx)
Brand or generic
Brand-name
Manufacturer
Exela Pharma
FDA application
NDA210660

What is Elcys?

From the FDA label:ELCYS ® (cysteine hydrochloride injection) is a sterile, nonpyrogenic solution for intravenous use. Each 50 mL of ELCYS ® contains 2500 mg of cysteine hydrochloride, USP (equivalent to 345 mg of cysteine) in water for injection. Sodium hydroxide and/or hydrochloric acid are used as needed to adjust the pH. The pH range is 1.0 to 2.5. The active ingredient is cysteine hydrochloride. Cysteine is a sulfur-containing amino acid. The chemical name of cysteine hydrochloride is L-cysteine hydrochloride monohydrate and is chemically designated as C 3 H 7 NO 2 S • HCI • H 2 O having a molecular weight of 175.63. Cysteine hydrochloride is a white crystalline powder soluble in water. Cysteine aqueous solution is prone to oxidation when exposed to air, and when mixed with amino acids solutions, cysteine may convert to insoluble cystine which leads to precipitation over time. It has the following structural formula: ELCYS ® contains no more than 120 mcg/L of aluminum. Structure

How to use

ELCYS ® is for admixing use only. Not for direct intravenous infusion . ( 2.1 ) • PHARMACY BULK PACKAGE: Dispense single-doses to many patients in a pharmacy admixture program. Use within 4 hours of puncture. ( 2.1 ) • See full prescribing information for information on preparation, administration, instructions for use, dosing considerations, including the recommended dosage in pediatric patients and adults. ( 2.1 , 2.2 , 2.3 , 2.4 , 2.5 ) 2.1 Important Administration Information Prior to administration, ELCYS® must be diluted and used as an admixture in PN solutions. ELCYS® is not for direct intravenous infusion. The resulting solution is for intravenous infusion into a central or peripheral vein. The choice of a central or peripheral venous route should depend on the osmolarity of the final infusate. Solutions with osmolarity of 900 mOsm/L or greater must be infused through a central catheter [see Warnings and Precautions ( 5.2 )] . ELCYS ® is supplied as a pharmacy bulk package, and consists of one pharmacy bulk vial which must be diluted prior to intravenous administration [see Dosage andAdministration ( 2.3 )]. As a pharmacy bulk vial, ELCYS ® is intended for dispensing of single doses to many patients. Dispensing from a pharmacy bulk vial should be completed within 4 hours after the vial is penetrated. Do not administer ELCYS ® as a direct, undiluted intravenous…

Side effects

The following serious adverse reactions are discussed in greater detail in other sections of the prescribing information: • Pulmonary embolism due to pulmonary vascular precipitates [see Warnings and Precautions ( 5.1 )] • Vein damage and thrombosis [see Warnings and Precautions ( 5.2 )] • Increased BUN [see Warnings and Precautions ( 5.3 )] • Acid-base imbalance [see Warnings and Precautions ( 5.4 )] • Hepatobiliary disorders [see Warnings and Precautions ( 5.5 )] • Hyperammonemia [see Warnings and Precautions ( 5.6 )] • Aluminum toxicity [see Warnings and Precautions ( 5.7 )] Adverse reactions with the use of cysteine hydrochloride injection were identified in clinical studies or postmarketing reports. Because some of these reactions were reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. • Local infusion site reactions, including a warm sensation, erythema, phlebitis and thrombosis at the infusion site • Generalized flushing, fever and nausea Most common adverse reactions are local reactions (warm sensation, erythema, phlebitis and thrombosis at the infusion site), generalized flushing, fever and nausea ( 6 ). To report SUSPECTED ADVERSE REACTIONS, contact Exela Pharma Sciences, LLC or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

Warnings

Important safety information

Pulmonary Embolism due to Pulmonary Vascular Precipitates: If signs of pulmonary distress occur, stop the infusion and initiate a medical evaluation. ( 5.1 ) • Vein Damage and Thrombosis: Solutions with osmolarity of 900 mOsm/L or more must be infused through a central catheter. ( 2.1 , 5.2 ) • Increased blood urea nitrogen (BUN): Monitor laboratory parameters and discontinue if exceeds normal postprandial limits and continues to increase. ( 5.3 ) • Acid-Base Imbalance: Monitor laboratory parameters and supplement with electrolytes as needed. ( 5.4 ) • Hepatobiliary Disorders: Monitor liver function parameters and ammonia levels. ( 5.5 ) • Hyperammonemia: Neurocognitive delay possible in infants; monitor blood ammonia levels. ( 5.6 , 8.4 ) • Aluminium Toxicity: Increased risk in patients with renal impairment, including preterm infants. ( 5.7 , 8.4 ) • Monitoring and Laboratory Tests: Monitor fluid and electrolytes, serum osmolarity, blood glucose, kidney and liver function, blood count and coagulation parameters throughout treatment. ( 5.8 ) 5.1 Pulmonary Embolism due to Pulmonary Vascular Precipitates Pulmonary vascular precipitates causing pulmonary vascular emboli and pulmonary distress have been reported in patients receiving PN. In some fatal cases, pulmonary embolism occurred as a result of calcium phosphate precipitates. Precipitation following passage through an in-line filter and suspected in vivo precipitate formation has also been reported. If signs of pulmonary distress occur, stop the PN infusion and initiate a medical evaluation. In addition to inspection of the solution [see Dosage and Administration ( 2.1 , 2.2 )], the infusion set and catheter should also periodically be checked for precipitates. 5.2 Vein Damage and Thrombosis ELCYS ® must be diluted and used as an admixture in PN solutions. It is not for direct intravenous infusion. Solutions with an osmolarity of 900 mOsm/L or greater must be infused through a central catheter [see Dosage and Administration ( 2.1 )] . The infusion of hypertonic nutrient injections into a peripheral vein may result in vein irritation, vein damage, and/or thrombosis. The primary complication of peripheral access is venous thrombophlebitis, which manifests as pain, erythema, tenderness or a palpable cord. Remove the catheter as soon as possible, if thrombophlebitis develops. 5.3 Increased Blood Urea Nitrogen (BUN) Intravenous infusion of amino acids may induce a rise in blood urea nitrogen (BUN), especially in patients with impaired hepatic or renal function. Appropriate laboratory tests should be performed periodically and infusion discontinued if BUN levels exceed normal postprandial limits and continue to rise. It should be noted that a modest rise in BUN normally occurs as a result of increased protein intake. Administration of amino acid solutions in the presence of impaired renal function may augment an increasing BUN, as does any protein dietary component. 5.4 Acid-Base Imbalance Administration of ELCYS ® may result in metabolic acidosis in preterm infants. Administration of amino acid solutions to a patient with hepatic impairment may result in serum amino acid imbalances, metabolic alkalosis, prerenal azotemia, hyperammonemia, stupor and coma. Frequent clinical evaluation and laboratory determinations are necessary for proper monitoring of acid-base balance during parenteral nutrition therapy. Significant deviations from normal concentrations may require the use of additional electrolyte supplements. 5.5 Hepatobiliary Disorders Hepatobiliary disorders are known to develop in some patients without preexisting liver disease who receive PN, including cholecystitis, cholelithiasis, cholestasis, hepatic steatosis, fibrosis and cirrhosis, possibly leading to hepatic failure. The etiology of these disorders is thought to be multifactorial and may differ between patients. Monitor liver function parameters and ammonia levels. Patients developing signs of hepatobiliary disorders should be assessed early by a clinician knowledgeable in liver diseases in order to identify possible causative and contributory factors, and possible therapeutic and prophylactic interventions. 5.6 Hyperammonemia Hyperammonemia is of special significance in infants, as it can result in neurocognitive delays. Therefore, it is essential that blood ammonia levels be measured frequently in infants. Instances of asymptomatic hyperammonemia have been reported in patients without overt liver dysfunction. The mechanisms of this reaction are not clearly defined but may involve genetic defects and immature or subclinically impaired liver function [see Contraindications ( 4 ), Use in Specific Populations ( 8.4 )] . 5.7 Aluminum Toxicity ELCYS ® contains aluminum that may be toxic. Aluminum may reach toxic levels with prolonged parenteral administration in patients with renal impairment. Preterm infants are particularly at risk for aluminum toxicity because their kidneys are immature, and they require large amounts of calcium and phosphate solutions, which also contain aluminum. Patients with renal impairment, including preterm infants, who receive greater than 4 to 5 mcg/kg/day of parenteral aluminum can accumulate aluminum to levels associated with central nervous system and bone toxicity. Tissue loading may occur at even lower rates of administration. Exposure to aluminum from ELCYS ® is not more than 0.21 mcg/kg/day when preterm and term infants less than 1 month of age are administered the recommended maximum dosage of ELCYS ® (15 mg cysteine/g of amino acids and 4 g of amino acids/kg/day) [see Table 1, Dosage and Administration ( 2.1 )] . When prescribing ELCYS ® for use in PN containing other small volume parenteral products, the total daily patient exposure to aluminum from the admixture should be considered and maintained at no more than 5 mcg/kg/day [see Use in Specific Populations ( 8.4 )] . 5.8 Monitoring and Laboratory Tests Monitor fluid and electrolyte status, serum osmolarity, blood glucose, liver and kidney function, blood count and coagulation parameters throughout treatment [see Dosage and Administration ( 2.4 )] .

Who should not take Elcys

ELCYS ® is contraindicated in: • Patients with known hypersensitivity to one or more amino acids. • Patients with inborn errors of amino acid metabolism due to risk of severe metabolic or neurologic complications. • Patients with pulmonary edema or acidosis due to low cardiac output. • Hypersensitivity to one or more amino acids ( 4 ) • Inborn errors of amino acid metabolism ( 4 ) • Pulmonary edema or acidosis due to low cardiac output ( 4 )

Overdose — what happens if you take too much

In the event of over hydration or solute overload, re-evaluate the patient and institute appropriate corrective measures [see Warnings and Precautions ( 5.3 , 5.4 , 5.5 , 5.7 , 5.8 )] .

U.S. Poison Control: call or text 1-800-222-1222 (free, 24/7). In an emergency call 911. From the FDA label; not medical advice.

Dosage forms

Injectable

The forms currently marketed in the U.S., per the FDA National Drug Code Directory.

Ways to save

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Frequently asked questions

Is there a coupon or discount for Elcys?
pharmaranks is an independent ratings site, not a pharmacy — we don't issue coupons or sell Elcys. To pay less, ask your prescriber or pharmacist whether a generic equivalent exists, check the manufacturer's copay/savings card and patient-assistance program, and compare a pharmacy discount card against your insurance copay. Prices vary by pharmacy, insurance, and location, so always confirm at the counter. This is general reference, not medical or financial advice.
Who makes Elcys?
Elcys is marketed by Exela Pharma. You can see Exela Pharma's full profile, rating, and other products on pharmaranks.
Is Elcys a brand-name or generic drug?
Elcys is a brand-name product with the active ingredient Cysteine Hydrochloride.
Is Elcys available over the counter?
No. Elcys is a prescription (Rx) medication in the US — you need a prescription from a licensed clinician (in person or via telehealth); it isn't sold over the counter. For some conditions there are OTC alternatives — ask your pharmacist.
What forms does Elcys come in?
Elcys is currently marketed as injectable, per the FDA's National Drug Code Directory.
Is Elcys FDA-registered?
Elcys is on record with the U.S. FDA under application number NDA210660. You can verify this on its official FDA label.
Is Elcys safe?
There's no single safe-or-not verdict, and we don't yet have a composite recall-safety score for Elcys. Review its FDA-label side effects and warnings below, and always consult a licensed professional.
What are the side effects of Elcys?
Elcys's side effects are taken directly from its FDA label. From the label: The following serious adverse reactions are discussed in greater detail in other sections of the prescribing information: • Pulmonary embolism due to pulmonary vascular precipitates [see Warnings and Precautions ( 5.1 )] • Vein damage and thrombosis [see Warnings and Precautions ( 5.2 )] • Increased… Both common and serious reactions are documented in full on this page. This is general reference from the FDA, not medical advice — always consult a professional.

Clinical content sourced from the FDA label via openFDA (U.S. FDA). View the FDA label on DailyMed → Provided for general reference only — not medical advice. Always consult a licensed professional and the current prescribing information.

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