Dextrose is a simple sugar chemically identical to the glucose that circulates in the bloodstream. It is manufactured from corn or wheat starch and is the D-isomer of glucose, the form the human body uses for fuel. Medically, dextrose is prepared as a sterile solution administered intravenously (IV). These injectable solutions are used in healthcare to rapidly restore blood sugar, provide necessary hydration, or deliver nutrition to patients.
How Dextrose Functions in the Body
Dextrose functions as the body’s primary source of energy, fueling cellular activity across all organs. Once infused intravenously, it is immediately available for metabolism, where it is oxidized into carbon dioxide and water, releasing energy. This energy is especially important for the central nervous system, as the brain relies almost exclusively on glucose to function properly.
Dextrose solutions are available in various concentrations, which determines their primary purpose in a clinical setting. A low concentration, such as 5% dextrose in water (D5W), provides minimal calories but is mostly used for fluid replacement or to keep a vein open for medication delivery. Higher concentrations (10%, 20%, 50%, or 70%) are considered hypertonic and provide a significant source of carbohydrate calories for patients who cannot eat.
Primary Reasons for Injection Therapy
One of the most common applications for dextrose injection is the rapid treatment of hypoglycemia, or critically low blood sugar. High-concentration solutions, frequently 50% dextrose (D50), are administered to quickly raise blood glucose levels in emergency situations. This rapid infusion is necessary when a person cannot take sugar by mouth due to unconsciousness or severe symptoms. Because of its high glycemic index, dextrose enters the bloodstream immediately, providing a fast-acting rescue.
Dextrose is also frequently used to restore fluid and volume balance in dehydrated patients. Solutions like D5W are often infused to correct water loss, acting as a vehicle for hydration. These solutions may also be combined with electrolytes, such as in D5NS (5% dextrose in normal saline), to replace both water and essential salts that have been lost. When the dextrose is metabolized, the remaining water is distributed throughout the body’s fluid compartments to help reestablish normal volume.
A third major use is providing nutritional support and acting as a drug vehicle for administering other medications. Patients who are unable to absorb nutrients through their digestive system may receive dextrose as a primary component of Total Parenteral Nutrition (TPN). In this context, concentrated dextrose, often 20% to 70%, is mixed with amino acids, fats, and vitamins to deliver all necessary calories and nutrients intravenously. Furthermore, because dextrose is compatible with many drugs, the 5% solution is regularly used as a sterile, non-irritating diluent to safely infuse various medications into a patient’s vein.
Administering Dextrose and Potential Side Effects
Dextrose solutions are almost exclusively administered intravenously, allowing for direct access to the circulatory system. The specific concentration dictates the appropriate administration technique. Lower concentrations, like D5W, can typically be infused into a smaller peripheral vein in the arm or hand.
However, hypertonic solutions, such as D50 or highly concentrated nutritional admixtures, must be given slowly through a central venous catheter. Infusing these highly concentrated solutions rapidly or through a small peripheral vein can cause significant irritation and inflammation of the vein wall, a condition known as phlebitis. Regular checks of blood glucose levels are necessary to ensure the body is tolerating the influx of sugar.
Several potential side effects are associated with dextrose injections, especially when administered too quickly or in high volume. The most common risk is induced hyperglycemia, or high blood sugar, which can occur if the infusion rate is too fast or if the patient’s body cannot process the glucose effectively. Other localized reactions at the injection site include pain, burning, and swelling, which may signal that the solution is irritating the vein or has leaked into the surrounding tissue. Excess use of dextrose solutions without electrolytes can also lead to electrolyte imbalances, such as low blood sodium or potassium levels.