IVIG Dose Calculator

Intravenous immunoglobulin, usually abbreviated IVIG, is a concentrated preparation of antibodies pooled from screened donors. It is prescribed for selected immune deficiencies, autoimmune conditions, inflammatory disorders, and neurologic diseases. Many regimens are expressed as grams of immunoglobulin per kilogram of dosing weight. Multiplying the prescribed g/kg amount by the appropriate weight produces a preliminary total dose in grams. Choosing the appropriate dosing weight can be clinically important. This calculator first estimates ideal body weight with the Devine formula. For males, ideal weight begins at 50 kg at five feet and adds 2.3 kg for each inch above five feet. For females, it begins at 45.5 kg and adds the same increment. If actual body weight is more than 120 percent of ideal weight, the calculator applies an adjusted body weight formula: ideal weight plus 40 percent of the difference between actual and ideal weight. Otherwise it uses actual weight. This approach reflects one commonly used stewardship protocol, but it is not universal. Hospitals, blood services, insurers, and specialty guidelines may specify a different scalar, threshold, capped dose, rounding rule, or use of lean, ideal, or actual weight. The indication also determines the prescribed g/kg regimen, frequency, division across treatment days, and maximum infusion rate. Never infer a prescription from an example on this page. The entered dose must come from an authorized order and should be checked against the protocol applicable to the product and condition. The total grams do not determine vial selection or infusion settings by themselves. IVIG products vary in concentration, vial size, stabilizers, osmolality, sodium, IgA content, storage, and administration instructions. Patient factors such as renal function, thrombosis risk, hydration, previous reactions, age, cardiac status, and concurrent medicines can influence product selection and monitoring. Dose rounding may reduce waste but should follow approved policy. Use the result as an independent arithmetic aid, not as authorization to prepare or administer treatment. A pharmacist or qualified clinician should confirm the indication, weight basis, product, dose, schedule, premedication, laboratory monitoring, and infusion protocol. Stop and resolve any difference between this estimate and the official order. Urgent symptoms during an infusion require immediate clinical assessment according to local emergency procedures.