Glycine

1.5% Glycine Irrigation, USP is indicated for use as irrigating fluid during transurethral prostatic resection and other transurethral surgical procedures.

1.5% Glycine Irrigation, USP should be administered only by transurethral instillation with appropriate urologic instrumentation. A disposable irrigation set should be used. The total volume of solution used for irrigation is solely at the discretion of the surgeon.

Height of container(s) above the operating table in excess of 60 cm (approx. 2 ft.) has been reported to increase intravascular absorption of the irrigating fluid.

Additives may be incompatible. Consult with pharmacist, if available. When introducing additives, use aseptic technique, mix thoroughly and do not store.

Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution container permits. See PRECAUTIONS.

Adverse reactions may result from intravascular absorption of glycine. Large intravenous doses of glycine are known to cause salivation, nausea and lightheadedness. Other consequences of absorption of urologic irrigating solutions include fluid and electrolyte disturbances such as acidosis, electrolyte loss, marked diuresis, urinary retention, edema, dryness of mouth, thirst, dehydration, coma from hyponatremia, secondary hyponatremia due to fluid overload, and hyperammonemia with resultant coma and/or encephalopathy; cardiovascular disorders such as hypotension, tachycardia, angina-like pains; pulmonary disorders such as pulmonary congestion; and other general reactions such as blurred vision, convulsions, nausea, vomiting, rhinitis, chills, vertigo, backache, transient blindness and urticaria. Allergic reactions from glycine are unknown or exceedingly rare.

Should any adverse reaction occur, discontinue the irrigant, evaluate the patient, institute appropriate therapeutic countermeasures and save the remainder of the fluid for examination if deemed necessary.

1.5% Glycine Irrigation, USP is a sterile, nonpyrogenic, hypotonic, aqueous solution of glycine intended only for urologic irrigation during transurethral surgical procedures.

Each 100 mL contains 1.5 g of glycine in water for injection. The solution is nonelectrolytic, hypotonic and has an osmolarity of 200 mOsmol/liter (calc.); pH 6.0 (4.5 to 6.5).

The solution contains no bacteriostat, antimicrobial agent or added buffer and is intended only for use as a single-dose irrigation. When smaller volumes are required, the unused portion should be discarded.

1.5% Glycine Irrigation is a urologic nonelectrolyte irrigant.

Glycine, USP is chemically designated aminoacetic acid (C₂H₅NO₂), a white crystalline powder freely soluble in water. It has the following structural formula:

NH₂CH₂COOH

Water for Injection, USP is chemically designated H₂0.

The flexible plastic container is fabricated from a specially formulated polyvinylchloride. Water can permeate from inside the container into the overwrap but not in amounts sufficient to affect the solution significantly.

The semi-rigid container is fabricated from a specially formulated polyolefin. It is a copolymer of ethylene and propylene. The container requires no vapor barrier to maintain the proper drug concentration.

The flexible plastic container is fabricated from a specially formulated polyvinylchloride. Water can permeate from inside the container into the overwrap but not in amounts sufficient to affect the solution significantly. Solutions in contact with the plastic container may leach out certain chemical components from the plastic in very small amounts; however, biological testing was supportive of the safety of the plastic container materials. Exposure to temperatures above 25°C/77°F during transport and storage will lead to minor losses in moisture content. Higher temperatures lead to greater losses. It is unlikely that these minor losses will lead to clinically significant changes within the expiration period.

Glycine is an amino acid and a nonelectrolyte. A solution of glycine in water is therefore nonconductive and suitable for urologic irrigation during electrosurgical procedures. A 1.5% concentration of glycine in water (200 mOsmol/liter calc.) is sufficient to minimize the risk of intravascular hemolysis which can occur from absorption of plain water through open prostatic veins during transurethral resection (TUR). It is hypotonic in relation to the extracellular fluid (280 mOsmol/liter). Any solution absorbed intravascularly during transurethral prostatic or bladder surgery, although variable in amount depending primarily on the extent of surgery, will be excreted by the kidney. Studies have shown that the absorption of glycine does not cause significant hemolysis (increase of free hemoglobin) or release significant amounts of free ammonia in the blood. Glycine is rapidly degraded in the liver by glycine oxidase.

Water is an essential constituent of all body tissues and accounts for approximately 70% of total body weight. Average normal adult daily requirement ranges from two to three liters (1.0 to 1.5 liters each for insensible water loss by perspiration and urine production).

Water balance is maintained by various regulatory mechanisms. Water distribution depends primarily on the concentration of electrolytes in the body compartments and sodium (Na⁺) plays a major role in maintaining physiologic equilibrium.