Immunomodulatory drugs for maintaining remission in polyarteritis nodosa

For people with polyarteritis nodosa, long-term high-dose oral corticosteroids are continued until remission of disease activity is achieved (ie the patient’s symptoms resolve, their organ function stabilises and their inflammatory markers normalise). The optimal duration is unknown.

The dose may then be tapered very slowly under specialist advice. An example of tapering long-term, high-dose oral corticosteroids can be found in Example of tapering long-term, high-dose oral corticosteroids for systemic vasculitides.

Combination therapy, with oral corticosteroids and another immunomodulatory drug, is recommended for corticosteroid sparing (to minimise the total dose and adverse effects of corticosteroids)Maz, 2021. Cyclophosphamide can be added to oral corticosteroid therapy for severe polyarteritis nodosa (associated with signs of organ involvement or progressive disease despite adequate oral corticosteroid therapy). Protocols vary, but dosage regimens for cyclophosphamide, in combination with oral corticosteroids, for polyarteritis nodosa includede Groot, 2009Hocevar, 2021:

For additional considerations specific to cyclophosphamide use, see Specific considerations for use of conventional synthetic disease-modifying antirheumatic drugs (csDMARDs).

Rituximab is a B cell–targeting biological (b)DMARD that may be used in people with refractory disease or contraindications to cyclophosphamide; the usual dosage is:

For additional considerations specific to rituximab use, see Specific considerations for use of biological or targeted-synthetic disease-modifying antirheumatic drugs (b/tsDMARDs).

In the maintenance phase, combination therapy with oral corticosteroids and another immunomodulatory drug (eg cyclophosphamide, rituximab, azathioprine, methotrexate) is usually required.