Ionosol MB and 5% Dextrose Injection contains a hypotonic concentration of electrolytes with dextrose. The letters "MB" mean "modified Butler's" solution; the modified solution contains 5 mEq less sodium, 5 mEq more potassium, and 3 mEq added magnesium, as compared with the original Butler's solution. The modified solution can be used in pediatric patients for treatment of dehydration, acidosis, diarrhea, or burns, and in adults for postoperative fluid and electrolyte therapy.

Solutions containing dextrose restore blood glucose levels and provide calories. Carbohydrate in the form of dextrose may aid in minimizing liver glycogen depletion and exerts a protein-sparing action. Dextrose injected parenterally undergoes oxidation to carbon dioxide and water.

The lactate anion provides an alkalizing effect resulting from simultaneous removal by the liver of lactate and hydrogen ions. In the liver, the lactate is metabolized to glycogen which is ultimately converted to carbon dioxide and water by oxidative metabolism.

The lactate anion acts as a source (alternate) of bicarbonate when normal production and utilization of lactic acid is not impaired as a result of disordered lactate metabolism. Since metabolic conversion is dependent on the integrity of cellular oxidative processes, lactate may be inadequate or ineffective as a source of bicarbonate in patients suffering from acidosis associated with shock or other disorders involving reduced perfusion of body tissues. When oxidative activity is intact, one to two hours time is required for metabolism of lactate.

Magnesium chloride in water dissociates to provide magnesium (Mg++) and chloride (Cl‾) ions. Magnesium is the second most plentiful cation of the intracellular fluids. It is an important cofactor for enzymatic reactions and plays an important role in neurochemical transmission and muscular excitability. Normal plasma concentration ranges from 1.5 to 2.5 or 3.0 mEq/liter. Magnesium is excreted solely by the kidney at a rate proportional to the plasma concentration and glomerular filtration.

Phosphate is one of the three major intracellular electrolytes (along with potassium and magnesium) and the largest anion component found within the cells. Its concentration and excretion are largely dependent on intake, acid-base balance and endocrine function. Its metabolism follows that of calcium in many respects. Phosphate anion in electrolyte solutions may help to repair phosphate deficiency.

Potassium chloride in water dissociates to provide potassium (K+) and chloride (Cl‾) ions. Potassium is the chief cation of body cells (160 mEq/liter of intracellular water). It is found in low concentration in plasma and extracellular fluids (3.5 to 5.0 mEq/liter in a healthy adult and child over 10 days old; 3.5 to 6.0 mEq/liter in a child less than 10 days old). Potassium plays an important role in electrolyte balance. Normally about 80 to 90% of the potassium intake is excreted in the urine; the remainder in the stools and to a small extent, in the perspiration. The kidney does not conserve potassium well so that during fasting or in patients on a potassium-free diet, potassium loss from the body continues resulting in potassium depletion.

Water is an essential constituent of all body tissues and accounts for approximately 70% of total body weight. Average normal adult daily requirement ranges from two to three liters (1.0 to 1.5 liters each for insensible water loss by perspiration and urine production). Average normal pediatric daily requirements are based on the child's weight as described in the table below: 

Water balance is maintained by various regulatory mechanisms. Water distribution depends primarily on the concentration of electrolytes in the body compartments, and sodium (Na+) plays a major role in maintaining physiologic equilibrium.

Ionosol MB and 5% Dextrose Injection contains a hypotonic electrolyte concentration. This should not be confused with the total tonicity (electrolytes plus nonelectrolytes) of solutions containing both electrolytes and dextrose. In general, solutions providing isotonic electrolyte concentrations are most applicable to replacement of acute deficits, whereas hypotonic electrolyte concentrations are best suited for parenteral maintenance of water requirements when only small quantities of electrolytes are desired.