Overview
This lecture covers the process of reconstituting powdered drugs for injection, focusing on reading medication labels and calculating the correct dosage.
Understanding Drug Reconstitution
- Some injectable medications come as powders, cakes, or wafers that must be dissolved before use.
- A diluent is the liquid injected into the medication vial to dissolve the powder.
- The type and amount of diluent and the resulting concentration are specified on the medication label.
- The entire reconstitution process depends on carefully following label instructions.
Reading Medication Labels
- Labels provide key information: the volume of diluent to add and the final drug concentration (e.g., 60 mg/mL).
- Always check which diluent to use (e.g., sterile water) and the exact volume required.
- Some labels offer options for achieving different concentrations by varying the amount of diluent.
Calculating Dosages
- After reconstitution, calculate the volume to administer based on the ordered dose and the concentration.
- Use ratio-proportion method: set up a proportion using concentration (mg/mL) and solve for the required volume.
- Example: To give 1.5 mg from a solution of 0.5 mg/mL, set up 0.5/1 = 1.5/x, solve for x to get 3 mL.
Adjusting Concentration
- Adding more or less diluent changes the concentration of the medication.
- Some labels provide a chart indicating how much diluent to add for specific concentrations.
- The fluid volume to inject depends on the ordered dose and desired concentration.
Key Terms & Definitions
- Reconstitution — Process of dissolving a powdered medication with a liquid (diluent) to prepare it for injection.
- Diluent — The liquid (e.g., sterile water) used to dissolve or dilute a medication.
- Concentration — Amount of drug in a specific volume of solution (e.g., mg/mL).
- Ratio-Proportion — A method for calculating medication dosages using equivalent ratios.
Action Items / Next Steps
- Review and complete the practice sheets on drug reconstitution.
- Preview the next unit on the ratio-proportion method before attempting the practice sheet.