General

R-Gene 10 is a hypertonic (950 mOsmol/liter) and acidic (average pH of 5.6) solution that can cause irritation and damage to tissues. Care should be used to ensure administration of R-Gene 10 through a patent catheter within a patent vein. Excessive rates of infusion may result in local irritation and in flushing, nausea, or vomiting. Inadequate dosing or prolongation of the infusion period may diminish the stimulus to the pituitary and nullify the test.

The arginine in R-Gene 10 can be metabolized resulting in nitrogen-containing products for excretion. The effect of an acute amino acid or nitrogen burden upon patients with impairment of renal function should be considered when R-Gene 10 is to be administered.

The chloride content of R-Gene 10 is 47.5 mEq per 100 mL of solution, and the effect of infusing this amount of chloride into patients with electrolyte imbalance should be evaluated before the test is undertaken.

It should be noted that the basal and post stimulation levels of growth hormone are elevated in patients who are pregnant or are taking oral contraceptives.

Carcinogenesis, mutagenesis, and impairment of fertility

Long term animal studies have not been performed to evaluate the carcinogenic potential, the mutagenic potential or the effect on fertility of intravenously administered R-Gene 10.

Pregnancy

Reproduction studies have been performed in rabbits and mice at doses 12 times the human dose and have revealed no evidence of impaired fertility or harm to the fetus due to R-Gene 10 (10% Arginine Hydrochloride Injection, USP). There have been no adequate or well controlled studies for the use of R-Gene 10 in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should not be used during pregnancy.

Nursing Mothers

It is not known whether intravenous administration of R-Gene 10 could result in significant quantities of arginine in breast milk. Systemically administered amino acids are secreted into breast milk in quantities not likely to have a deleterious effect on the infant. Nevertheless, caution should be exercised when R-Gene 10 is to be administered to nursing women.

Geriatric Use

Clinical studies of arginine did not include a sufficient number of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients.

Post Marketing Experience

The following adverse events have been reported during post-marketing use: extravasation leading to burn-like reaction and/or skin necrosis requiring surgical intervention, hypersensitivity reactions including anaphylaxis, and hematuria that in some cases occurred 1–2 days after an R-Gene 10 administration. Because these adverse events are 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.

Adult Dosage

The recommended adult dose is 30 g arginine hydrochloride (300 mL of R-Gene 10) administered by intravenous infusion over 30 minutes. The total dose should not exceed 30 g arginine hydrochloride. See Directions for Use for preparation instructions.

Pediatric Dosage

The recommended pediatric dose is 0.5 g/kg arginine hydrochloride (5 mL/kg of R-Gene 10) administered by intravenous infusion over 30 minutes. The total dose should not exceed 30 g arginine hydrochloride.

• For patients weighing 59 kg or less, withdraw a weight based dose from a sealed R-Gene 10 bottle and place in a separate container for intravenous infusion to avoid the inadvertent delivery and administration of the total volume from the commercially available container. See Directions for Use for preparation instructions.
• For patients weighing 60 kg or more, the recommended dose is 30 g arginine hydrochloride (300 mL of R-Gene 10). See Directions for Use for preparation instructions

Test Procedure

The intravenous infusion of R-Gene 10 is a part of the test for measurement of pituitary reserve of human growth hormone and, for successful administration of the test, clinical conditions and procedures should be as follows:

1. The test should be scheduled in the morning following a normal night's sleep, and an overnight fast should continue through the test period.
2. Patients must be placed at bed rest for at least 30 minutes before the infusion begins. Care should be taken to minimize apprehension and distress. This is particularly important in children.
3. R-Gene 10 (Arginine Hydrochloride Injection, USP) is a hypertonic solution and should only be infused through an indwelling needle or soft catheter placed in an antecubital vein or other suitable vein (see PRECAUTIONS). Blood samples should be taken by venipuncture from the contra-lateral arm.
4. A desirable schedule for drawing blood samples is at −30, 0, 30, 60, 90, 120 and 150 minutes.
5. R-Gene 10 should be infused beginning at zero time at a uniform rate which will permit the recommended dose to be administered over 30 minutes.
6. Blood samples should be promptly centrifuged and the plasma stored at −20°C until assayed by one of the published radioimmunoassay procedures.
7. Diagnostic test results showing a deficiency of pituitary reserve for HGH should be confirmed by a second test with R-Gene 10, or one may elect to confirm with the insulin hypoglycemia test. A waiting period of one day is advised between tests.

Directions for Use

R-Gene 10 is provided as a ready-to-use solution for patients weighing 60 kg (132 lbs) or more and should not be further diluted. For pediatric patients weighing 59 kg (130 lbs) or less a dose must be placed in a separate container. Follow the preparation instructions below.

Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration whenever solution and container permit.