Compatibility of aminophylline and verapamil in intravenous admixtures.

Published

Journal Article

The chemical and visual compatibility of aminophylline and verapamil hydrochloride in intravenous admixtures was evaluated. Verapamil hydrochloride injection was added to a solution of aminophylline 1.0 mg/mL in 5% dextrose injection (D5W) to yield final verapamil hydrochloride concentrations of 0.1 and 0.4 mg/mL. Each solution type was prepared in triplicate. An aliquot from each of these solutions was assayed in duplicate for theophylline and verapamil by high-performance liquid chromatography at 0, 4, 8, 12, and 24 hours after mixing. All aliquots were filtered with a 0.22-micron filter immediately before assay. At each time interval, samples were assessed for pH and inspected visually and microscopically for evidence of incompatibility. Theophylline concentrations showed less than 10% change over 24 hours in the two-drug admixtures. Less than 1% of the original verapamil concentrations remained immediately after mixing with aminophylline injection in D5W. Turbidity was readily apparent in the admixture containing verapamil hydrochloride 0.4 mg/mL; however, microscopic evaluation revealed precipitate in both solutions. Solution pH was determined to be a primary cause of precipitation. The mean pH values for the verapamil hydrochloride 0.1 and 0.4 mg/mL control solutions were 4.09 and 4.36, respectively. The mean pH of the aminophylline 1.0 mg/mL control solution was 8.35. The mean pH of the aminophylline-verapamil admixtures at verapamil hydrochloride concentrations of 0.1 and 0.4 mg/mL was 8.14 and 8.06, respectively. Verapamil hydrochloride injection in final concentrations of 0.1 and 0.4 mg/mL is incompatible with aminophylline 1.0 mg/mL in D5W.

Full Text

Duke Authors

Cited Authors

  • Johnson, CE; Lloyd, CW; Mesaros, JL; Rubley, GJ

Published Date

  • January 1989

Published In

Volume / Issue

  • 46 / 1

Start / End Page

  • 97 - 100

PubMed ID

  • 2712035

Pubmed Central ID

  • 2712035

International Standard Serial Number (ISSN)

  • 0002-9289

Language

  • eng

Conference Location

  • United States