IVIg Dosing Guide | IVIGdosing.com

Step 1

Find an indication

Search directly for a condition or browse by department to confirm whether IVIG is recommended, discouraged, or not indicated.

Department

Condition

Common Searches

Tap a common indication to auto-fill the guide

Select a condition above to see dosage instructions.

Step 2

Calculate the dose

Keep the current formula, but surface the inputs and outputs in a cleaner clinical workflow.

Weight

Actual body weight is always the starting point. Adult obesity adjustments are applied automatically when IBW can be estimated.

Height

Adult height is used to estimate IBW and adjusted body weight. Pediatric and pregnancy modes hide this step.

Gender

Used only for adult IBW estimation in the current calculator.

Prescribed Dosage

g/kg

Dose can be entered manually or auto-populated from a selected indication when IVIG is recommended.

Calculation Results

Ideal Body Weight (IBW) -- kg

Adjusted Body Weight -- kg

Total IVIg Dose

0 g

Daily Plan

Split the total dose across the planned infusion schedule.

Split over

Enter dosage above to see breakdown

Calculations automatically use Adjusted Body Weight for obese patients (BMI > 30) per clinical guidelines.

Stewardship

Evidence-based use and supply reality

IVIG is derived from the pooled plasma of thousands of donors — it is not a synthesized drug. The US supplies approximately 70% of the world's plasma; collection fell 18% during 2020, precipitating global shortages. Prescribing carries both a clinical and a supply responsibility.

Evidence grades by indication

Grade AKawasaki disease — IVIG 2 g/kg reduces coronary artery aneurysm from ~25% to ~4% (Newburger et al., NEJM 1986; AHA Guidelines 2017)
Grade ACIDP — ICE trial: NNT ≈ 4 for sustained response (Hughes et al., Lancet Neurology 2008; Cochrane 2024)
Grade AGBS — Equivalent efficacy to plasmapheresis (van der Meché & Schmitz, NEJM 1992; Cochrane 2014)
Grade AITP (acute) — Rapid platelet augmentation before procedures; not appropriate for long-term maintenance (AAN / ASH Guidelines)
Grade BMyasthenia gravis — AAN Level B evidence for acute exacerbation; equivalent to plasmapheresis short-term
Grade BPrimary immunodeficiency — Established standard of care; reduces serious infections (ESID Guidelines 2020)

Dosing in obesity

Using actual body weight (ABW) in obese patients risks serious overdose. Evidence supports adjusted body weight (AdjBW):

AdjBW = IBW + 0.4 × (ABW − IBW)

Apply when BMI > 30. IBW: males 50 kg + 2.3 kg/inch over 5 ft; females 45.5 kg + 2.3 kg/inch over 5 ft. This calculator uses AdjBW automatically.

Stewardship principles

Confirm indication has evidence-based support before ordering
Use lowest effective dose; taper maintenance where possible
Reassess every 3–6 months — continued need must be documented
Canada is not plasma self-sufficient; each prescription has a supply impact

Adverse Effects

Reactions and serious complications

Overall adverse reaction rate is 25–34% per patient across published pharmacovigilance data (FAERS analysis, 76,138 reports, 2004–2024). Most reactions are mild-to-moderate and infusion-rate dependent. Slowing the infusion rate resolves the majority.

Common — rate dependent, usually resolve with infusion slowing

Headache

Most frequent ADR. Mechanism: vasospasm or sterile meningeal irritation from cytokine release or stabilizing agents. Migraine history is a strong risk factor for post-infusion aseptic meningitis.

Fever / Chills / Myalgia

Incidence ~13–18%. Mechanism: IL-6 and TNF-α release triggered by IgG aggregates or immune complex formation. Premedication with acetaminophen ± diphenhydramine may reduce severity.

Fatigue / Nausea / Flushing

Systemic inflammatory response; transient osmotic fluid shifts. Pediatric data (Côté et al., Transfusion 2025): fever 13.6%, headache 6.7% in children <18 years.

Serious — require monitoring, may necessitate stopping infusion

Hemolysis

Incidence: up to 32% mild; serious hemolysis less common but most frequent serious complication. Mechanism: passive transfer of donor anti-A/B isoagglutinins coat recipient RBCs → positive DAT, extravascular hemolysis. Non-O blood groups (A, B, AB) at highest risk, especially at doses ≥2 g/kg. CBS requires ABO group before high-dose IVIG; for non-O patients: obtain CBC, DAT, bilirubin, LDH, haptoglobin, reticulocyte count within 1 week of infusion. Isoagglutinin-depleted products now available to reduce risk. Cuesta et al., Transfusion 2022.

→ ABO group before high-dose; monitor CBC + LDH in non-O blood groups

Thromboembolism

Incidence: ~2.2% per patient. FDA black-box warning 2013; Health Canada warning also issued. Mechanism: hyperviscosity from high protein load and protein polymerization. Risk factors: cardiovascular disease, advanced age, immobilization, prior thrombosis, hypercoagulable state, high dose, rapid infusion. Onset during infusion up to 8 days post-IVIG (CBS). Risk mitigation: adequate hydration, lowest effective dose, slow infusion rate, use AdjBW to prevent overexposure. Do not resume after a thrombotic event.

→ Black-box warning; AdjBW dosing; slow infusion; pre-hydrate

Aseptic Meningitis Syndrome (AMS)

Incidence: 0.42–0.60%; majority of cases occur at 2 g/kg/cycle. Onset within 6–48 hours; most resolve within 5 days. Mechanism: direct meningeal irritation by high-dose IgG or stabilizers. Risk factors: high dose (>1 g/kg), rapid infusion rate, history of migraine. CSF: pleocytosis, elevated protein, normal-to-low glucose, sterile cultures. Management: stop infusion; do not resume; analgesics, antiemetics, IV fluids.

→ Stop infusion; do not resume; slow rate and pre-hydrate to prevent

Acute Renal Failure

Onset 1–10 days post-IVIG. Risk factors: pre-existing CKD, diabetes, age >64, volume depletion, sepsis, nephrotoxic drugs. CBS notes sucrose-stabilized formulations carry higher nephrotoxicity risk; these are not currently licensed in Canada, though renal impairment has also been reported with sucrose-free products. Some nephrologists cap IVIG at 140 g/day in kidney transplant recipients. Management: pre-hydrate all patients; slow infusion rate; monitor creatinine; if function declines, discontinue (SCIG is an alternative).

→ Pre-hydrate; monitor creatinine; cap 140 g/day in renal transplant

TRALI

Extremely rare with IVIG — approximately 17 total cases in literature, case fatality ~24%. Mechanism: donor HLA or HNA antibodies activate recipient neutrophils in pulmonary microvasculature → non-cardiogenic pulmonary edema. Onset within 6 hours of infusion. Management: stop infusion; oxygen, respiratory support; chest X-ray (bilateral infiltrates without elevated pulmonary pressures); no diuretics. CBS requires immediate contact with Transfusion Medicine Laboratory and Canadian Blood Services.

→ Within 6h: bilateral infiltrates, O₂ sats ↓ → TRALI protocol; contact CBS

Anaphylaxis — IgA deficiency

Incidence: 5.7 per 10,000 administrations. Mechanism: trace IgA in IVIG product triggers massive mast cell degranulation in patients with anti-IgA antibodies. Routine serum IgA screening is not required before first-dose IVIG. Consider IgA level and anti-IgA testing only in patients with prior anaphylactic or recurrent severe allergic reactions to blood products/IVIG; product selection (e.g., Gammagard S/D — lowest IgA content at 2.2 µg/mL) may be modified in that setting. Ensure epinephrine is immediately available; monitor during infusion.

→ Screen IgA only if prior anaphylaxis or severe allergy to blood products/IVIG

Pre-infusion Checklist

Patient counseling and pre-treatment screening

The following steps should be completed before the first infusion and reviewed at each subsequent cycle.

Serum IgA screening

Routine serum IgA screening is not required before first-dose IVIG. Consider IgA level and anti-IgA testing only in patients with a history of prior anaphylactic or recurrent severe allergic reactions to blood products/IVIG; if clinically necessary, product selection may be modified in that setting.

Hydration

FDA-mandated counseling point. Ensure adequate oral or IV hydration before and during infusion to reduce risk of renal impairment, thrombosis, and headache. Patients should drink 2L of water in the 24h prior to infusion unless contraindicated.

Blood product consent

IVIG is a pooled human blood product. Discuss the extremely low (but non-zero) risk of transfusion-transmitted infections. Document informed consent per institutional policy.

Vaccination deferral — live attenuated vaccines

IVIG passively transfers antibodies that interfere with the immune response to live parenteral vaccines (MMR, MMRV, varicella). Per the Canadian Immunization Guide: defer 8 months after 0.3–0.4 g/kg; defer 10 months after 1 g/kg; defer 11 months after 2 g/kg. Inactivated vaccines (influenza, COVID-19) and oral/intranasal vaccines may be given at any time relative to IVIG. Patients on continuous SCIG should not receive MMR, MMRV, or varicella vaccines.

Symptoms to report immediately

Advise patients to report: shortness of breath or chest tightness (→ TRALI / anaphylaxis), severe headache with stiff neck (→ AMS), dark urine or jaundice (→ hemolysis), leg swelling or acute chest pain (→ VTE), decreased urine output (→ renal). Stop infusion and call provider immediately.

Infusion rate protocol

Start at 0.5–1.0 mg/kg/min; advance in increments every 15–30 minutes if tolerated. Most adverse reactions are infusion-rate dependent — slow the rate before stopping. First-time infusions should always start low and slow, regardless of formulation.