DrugLib.com — Drug Information Portal

Rx drug information, pharmaceutical research, clinical trials, news, and more

Glucagon (Glucagon Hydrochloride) - Description and Clinical Pharmacology

 
 



DESCRIPTION

Glucagon for Injection (rDNA origin) is a polypeptide hormone identical to human glucagon that increases blood glucose and relaxes smooth muscle of the gastrointestinal tract. Glucagon is synthesized in a special non-pathogenic laboratory strain of bacteria that has been genetically altered by the addition of the gene for glucagon. Escherichia coli

Glucagon is a single-chain polypeptide that contains 29 amino acid residues and has a molecular weight of 3483.

The empirical formula is C H N O S. The primary sequence of glucagon is shown below. 153 225 43 49

Crystalline glucagon is a white to off-white powder. It is relatively insoluble in water but is soluble at a pH of less than 3 or more than 9.5.

Glucagon is available for use intravenously, intramuscularly, or subcutaneously in a kit that contains a vial of sterile glucagon and a syringe of sterile diluent. The vial contains 1 mg (1 unit) of glucagon and 49 mg of lactose. Hydrochloric acid may have been added during manufacture to adjust the pH of the glucagon. One International Unit of glucagon is equivalent to 1 mg of glucagon. The diluent syringe contains 12 mg/mL of glycerin, Water For Injection, and hydrochloric acid. 1

CLINICAL PHARMACOLOGY

Glucagon increases blood glucose concentration and is used in the treatment of hypoglycemia. Glucagon acts only on liver glycogen, converting it to glucose.

Glucagon administered through a parenteral route relaxes smooth muscle of the stomach, duodenum, small bowel, and colon.

Pharmacokinetics

Glucagon has been studied following intramuscular, subcutaneous, and intravenous administration in adult volunteers. Administration of the intravenous glucagon showed dose proportionality of the pharmacokinetics between 0.25 and 2.0 mg. Calculations from a 1 mg dose showed a small volume of distribution (mean, 0.25 L/kg) and a moderate clearance (mean, 13.5 mL/min/kg). The half-life was short, ranging from 8 to 18 minutes.

Maximum plasma concentrations of 7.9 ng/mL were achieved approximately 20 minutes after subcutaneous administration (). With intramuscular dosing, maximum plasma concentrations of 6.9 ng/mL were attained approximately 13 minutes after dosing. see Figure 1A

Glucagon is extensively degraded in liver, kidney, and plasma. Urinary excretion of intact glucagon has not been measured.

Pharmacodynamics

In a study of 25 volunteers, a subcutaneous dose of 1 mg glucagon resulted in a mean peak glucose concentration of 136 mg/dL 30 minutes after injection (). Similarly, following intramuscular injection, the mean peak glucose level was 138 mg/dL, which occurred at 26 minutes after injection. No difference in maximum blood glucose concentration between animal-sourced and rDNA glucagon was observed after subcutaneous and intramuscular injection. see Figure 1B

Figure 1 Mean (±SE) serum glucagon and blood glucose levels after subcutaneous injection of glucagon (1 mg) in 25 normal volunteers

-- advertisement -- The American Red Cross
 
Home | About Us | Contact Us | Site usage policy | Privacy policy

All Rights reserved - Copyright DrugLib.com, 2006-2017