2.1 Stimulation of Pancreatic Secretions, Including Bicarbonate to Aid in the Diagnosis of Exocrine Pancreas Dysfunction:
0.2 mcg/kg body weight by intravenous injection over 1 minute.
Gastroduodenal (Dreiling) Tube Collection Method(1):
A radiopaque, double-lumen tube is passed through the mouth following a 12-15 hour fast. Under fluoroscopic control, the opening of the proximal lumen of the tube is placed in the gastric antrum and the opening of the distal lumen just beyond the papilla of Vater. The positioning of the tube must be confirmed and the tube secured prior to synthetic human secretin testing. Intermittent negative pressure of 25-40 mmHg is applied to both lumens and maintained throughout the test. When duodenal contents have a pH of ≥ 6, a baseline sample of duodenal fluids is collected for a 10 minute period. A test dose of ChiRhoStim® 0.2 mcg if using the 16 mcg vial (0.1 mL) or 0.4 mcg if using the 40 mcg vial (0.1 mL) is injected intravenously to test for possible allergies. After one minute, if there are no signs of allergic reaction, ChiRhoStim® at a dose of 0.2 mcg/kg of body weight is injected intravenously over 1 minute. Duodenal fluid is collected for 60 minutes thereafter. The aspirate is divided into four collection periods of fifteen minutes each. The duodenal lumen of the tube is cleared with an injection of air after collection of each sample. Wide variation in volume of the aspirate is indicative of incomplete aspiration. Each sample of duodenal fluid is to be chilled and subsequently analyzed for volume and bicarbonate concentration. Exocrine pancreas dysfunction typically associated with chronic pancreatitis is indicated if the peak bicarbonate concentration for any sample ≤ 80 mEq/L.
Endoscopic Collection Method: Endoscopic Pancreatic Function Test (ePFT)(2-4):
After assessment of patients for sedation and analgesia, a test dose of ChiRhoStim® 0.2 mcg if using the 16 mcg vial (0.1 mL) or 0.4 mcg if using the 40 mcg vial (0.1 mL) is injected intravenously to test for possible allergies. After one minute, if there are no signs of allergic reaction, ChiRhoStim® at a dose of 0.2 mcg/kg of body weight is injected intravenously over 1 minute. An upper endoscopy is performed with conscious sedation, after topical anesthetic. All gastric fluid is aspirated through the endoscope and discarded. After small bowel intubation to the junction of the second and third portion of the duodenum, fluid is aspirated for 1 to 3 minutes and collected in 5 separate specimen traps at baseline (0), 15, 30, 45, and 60 minutes after secretin injection. The patients remain intubated with the upper endoscope for one hour in the left lateral decubitus position. Boluses of meperidine and midazolam in a 25:1 mg ratio are administered to maintain analgesia and sedation during the 1-hour procedure. Each sample of duodenal fluid is to be chilled and subsequently analyzed for volume and bicarbonate concentration. Exocrine pancreas dysfunction typically associated with chronic pancreatitis is indicated if the peak bicarbonate concentration for any sample ≤ 80 mEq/L.
2.2 Stimulation of Gastrin Secretion to Aid in Diagnosis of Gastrinoma:
0.4 mcg/kg body weight by intravenous injection over 1 minute.
The patient should fast for at least 12 hours prior to beginning the test. Prior to injection of ChiRhoStim®, two blood samples are drawn for determination of fasting serum gastrin levels (baseline values). Subsequently, a test dose of ChiRhoStim® 0.2 mcg if using the 16 mcg vial (0.1 mL) or 0.4 mcg if using the 40 mcg vial (0.1 mL) is injected intravenously to test for possible allergies. If there are no signs of allergic reaction, ChiRhoStim® at a dose of 0.4 mcg/kg of body weight is injected intravenously over 1 minute; post-injection blood samples are collected after 1, 2, 5, 10, and 30 minutes for determination of serum gastrin concentrations.
Gastrinoma is strongly indicated in patients who show an increase in serum gastrin concentrations of 110 pg/mL over basal level on any of the post injection samples.
2.3 Facilitation of the Identification of the Ampulla of Vater and Accessory Papilla During Endoscopic Retrograde Cholangiopancreatography (ERCP) to aid in cannulation of the pancreatic duct:
0.2 mcg/kg body weight by intravenous injection over 1 minute.
Administration of ChiRhoStim® may be given when difficulty is encountered by the endoscopist in identifying the ampulla of Vater for various reasons including: anatomic deformity secondary to prior surgery, radiation therapy, peptic ulcer disease, tumors, etc. or in identifying the accessory papilla in patients with pancreas divisum. A test dose of ChiRhoStim® 0.2 mcg if using the 16 mcg vial (0.1 mL) or 0.4 mcg if using the 40 mcg vial (0.1 mL) is injected intravenously to test for possible allergies. If there are no signs of allergic reaction, a dose of 0.2 mcg/kg of body weight intravenously over 1 minute may be administered and will result in visible excretion of pancreatic fluid from the orifices of these papillae enabling their identification and facilitating their cannulation.
2.4 ADMINISTRATION
ChiRhoStim® 16 mcg vial:Dissolve the contents of the ChiRhoStim® 16 mcg vial in 8 mL of Sodium Chloride Injection USP, to yield a concentration of 2 mcg/mL. Shake vigorously to ensure dissolution. Use immediately after reconstitution and discard any unused portion.
ChiRhoStim® 40 mcg vial:Dissolve the contents of the ChiRhoStim® 40 mcg vial in 10 mL of Sodium Chloride Injection USP, to yield a concentration of 4 mcg/mL. Shake vigorously to ensure dissolution. Use immediately after reconstitution and discard any unused portion.
For both strengths, the reconstituted drug product should be inspected visually prior to administration. If particulate matter or discoloration is seen, the product should be discarded.