Rituximab Use in Lactating Mothers with Pemphigus Vulgaris
Women should not breastfeed while receiving rituximab or for up to 12 months following the last infusion, as maternal IgG is excreted in human milk. 1
Guideline-Based Contraindication
The British Association of Dermatologists explicitly states that breastfeeding is contraindicated during rituximab therapy and for 12 months post-treatment due to antibody excretion into breast milk. 1 This recommendation is reinforced by FDA labeling, which advises against breastfeeding during treatment and for 6 months after the last dose. 2
Alternative Treatment Options Before Considering Rituximab
When no other options seem available, several safer alternatives should be exhausted first:
Prednisolone remains the cornerstone therapy and is compatible with breastfeeding at doses ≤20 mg daily, making it the preferred first-line agent. 3
Azathioprine combined with corticosteroids has been used successfully in pemphigus during lactation, with a more favorable safety profile than rituximab. 1
Intravenous immunoglobulin (IVIg) is safe during lactation and has demonstrated efficacy in severe pemphigus cases (7 of 8 patients responded well). 1
High-potency topical corticosteroids can be considered for localized disease, though systemic therapy is usually required. 3
Clinical Context for Rituximab Efficacy
While rituximab demonstrates excellent efficacy in pemphigus vulgaris (90-95% achieve clinical remission within 6 weeks), 4 and has been used successfully in women of childbearing age who later conceived, 5 these cases involved discontinuation before pregnancy—not continuation during lactation.
Risk-Benefit Analysis in Extreme Circumstances
If the mother's pemphigus vulgaris is truly life-threatening and refractory to all safer alternatives:
Breastfeeding must be discontinued if rituximab is administered. 1, 2
The infant should avoid live vaccines for at least 6 months after maternal exposure due to potential B-cell depletion effects. 1
Serious infection risk (including septicemia) and mortality (mean of 2 patients per cohort) must be weighed against disease severity. 4
Common Pitfalls to Avoid
Do not assume "no options are available" without confirming that prednisolone, azathioprine, and IVIg have been adequately trialed at appropriate doses. 1, 3
Do not underestimate the efficacy of combination therapy with prednisolone plus azathioprine, which remains highly effective for most pemphigus cases. 1
Do not overlook the 12-month breastfeeding restriction, as the FDA label specifies 6 months but dermatology guidelines extend this to 12 months for complete safety. 1, 2