MSK & Rheumatology/Conventional DMARDs (non-MTX)

Other conventional DMARDs

also: sulfasalazine · hydroxychloroquine · leflunomide

Overview

The non-methotrexate conventional synthetic DMARDs for rheumatoid arthritis — each with a signature monitoring/toxicity point.

Mechanism

Slow disease progression by immunomodulation. Sulfasalazine (5-ASA + sulfapyridine) and hydroxychloroquine (antimalarial — impairs lysosomal antigen processing) are milder; leflunomide inhibits pyrimidine synthesis.

Indications

Rheumatoid arthritis (alternatives/adjuncts to methotrexate)
Hydroxychloroquine: SLE; sulfasalazine: also IBD

The agents

SulfasalazinecsDMARD

Safe in pregnancy; reversible oligospermia; blood dyscrasias.

Hydroxychloroquineantimalarial DMARD

RETINOPATHY — baseline + annual eye screening after 5 years; mildest DMARD.

Leflunomidepyrimidine inhibitor

Hepatotoxicity, hypertension; teratogenic (long washout — colestyramine to remove).

Adverse effects

Hydroxychloroquine: irreversible retinopathy (bull's-eye maculopathy)serious

Eye screening.

Leflunomide: hepatotoxicity, hypertension, teratogenicityserious

Sulfasalazine: blood dyscrasias, rash, GI upsetcommon

Cautions & contraindications

Leflunomide in pregnancypregnancy

Teratogen, long half-life.

Hydroxychloroquine without eye monitoring (long-term)all

Interactions

Additive immunosuppression/hepatotoxicity

Monitoring & kinetics

Sulfasalazine/leflunomide: FBC, LFTs; hydroxychloroquine: annual retinal screen

Oral. Hydroxychloroquine is the safest in pregnancy; sulfasalazine also pregnancy-safe.

Source: NICE NG100 — Rheumatoid arthritis · BNF — DMARDs