What Is Cysteine Hydrochloride?

Cysteine hydrochloride is a dietary supplement often given to patients who are deficient in cysteine, an amino acid present in many protein-rich foods. It is often administered to the patient intravenously, especially for infants, to let the body absorb the supplement more effectively. As part of a solution, cysteine hydrochloride is usually combined with water and nitrogen for dilution and is added to another amino acid solution. The supplement should be administered right away after it is diluted; otherwise, it may become insoluble and cannot be absorbed by the body.

As an amino acid, cysteine is actually a byproduct of another amino acid called methionine. Consequently, cysteine is then converted to another amino acid called glutathione, which is one of the most powerful antioxidants that protects cells from being damaged. It also helps in distributing the nutrients in different cells. Infants, however, are not yet able to convert methionine to cysteine, which poses problems such as malnutrition and malabsorption. To treat such problems, physicians often administer cysteine hydrochloride injections to malnourished and premature infants, along with other amino acid injections.

Administration of cysteine hydrochloride is often safe and patients rarely suffer from an overdose, if not at all. Some reactions, however, may occur in the area where the needle is inserted, especially if other medication, like antibiotics, also passes through the same tube. These reactions can include redness and itchiness of the skin, inflammation of the vein, and a blood clot, and another infusion site should be created for either the antibiotics of the cysteine supplement. Some side effects can also be experienced, such as constipation and shock, the latter probably a result of a blood clot and may possibly be fatal. Physicians often advise against administering the supplement if the patient has a liver disorder or a metabolic condition like diabetes, as the solution can be toxic to the patient.

Pregnant women should also check for their physician's approval before receiving cysteine hydrochloride. Manufacturers often supply 10mL vials of solution, each containing 0.5 grams of cysteine hydrochloride. The solution is then combined with other amino acid solutions and an appropriate amount of dextrose. The vials should be stored in a controlled temperature of 68 to 77°F (around 20 to 25°C), and should not be frozen. Before administration, the solution should also be inspected if any discoloration and particles are present, as only a clear solution should be used.