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Nursing Field Notes / Musculoskeletal · Pharmacology Course

DMARDs 🦾

Disease-Modifying Antirheumatic Drugs

NG-114 Musculoskeletal · Group D ADHD-friendly visual edition

The drug class that actually SLOWS the disease — not just the pain. Used mainly for rheumatoid arthritis (RA), DMARDs work by suppressing the immune system so it stops attacking the joints. Prototype = methotrexate, dosed ONCE WEEKLY — never daily.

📄 Simple Nursing original — opens in Drive →

🦠 ImmunosuppressantsDMARDs turn the immune system DOWN — that's how they help RA and how they cause infection risk.
🚨 WEEKLY not dailyMethotrexate is dosed once a week. Daily dosing is a fatal medication error.
🍊 Folic acidGiven WITH methotrexate to cut GI/liver side effects — does not block the RA benefit.
🩻 TB screen firstBiologic DMARDs (the -mab/-cept drugs) need a TB test before starting.
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ACTION

STEP 1 · HOW IT WORKS

DMARDs don't just numb pain — they turn down the immune attack that is destroying the joint.

🎯 Why DMARDs get added — pain relievers alone aren't enough

When RA pain and immobility can no longer be controlled by NSAIDs and other anti-inflammatories alone, DMARDs are added. They have immunosuppressive properties that decrease the body's immune response — the immune attack on the synovium is exactly what's destroying the joint, so dialing it down protects the joint from further damage.

🔥 NO DMARD immune system attacks the joint synovium (joint lining) = immune cells swarming, unchecked ✅ WITH DMARD immune response suppressed synovium (joint lining) = immune attack dialed down, joint spared
🧠 "DMARDs Modify the Disease." NSAIDs and steroids only treat the symptom (pain/swelling) — DMARDs are the only class that actually slows joint destruction.

💊 Prototype: Methotrexate — folate antagonist

Blocks an enzyme in the folate pathway, which shuts down rapidly dividing cells — including the overactive immune cells attacking the joint. At the low weekly RA dose it's immunosuppressive/anti-inflammatory (very different from the high daily doses used in chemotherapy).

🧠 Methotrexate = "Mother of DMARDs." It's the first-line, most-prescribed DMARD and the one every other drug on this page gets compared to.

🧬 Biologic DMARDs — the -mab / -cept drugs

Generic (trade)Dose
Adalimumab (Humira)40 mg subQ every other week
Etanercept (Enbrel)25 mg subQ twice weekly or 50 mg subQ weekly

Both are TNF-alpha inhibitors — they block a specific inflammatory messenger instead of suppressing the whole immune system broadly.

🧠 -mab = monoclonal antibody. -cept = receptor fusion protein (etanercept). Both end in a decoy that soaks up TNF-alpha before it can inflame the joint.

🦟 Other DMARDs worth knowing

  • Hydroxychloroquine (Plaquenil) — antimalarial repurposed for RA, typically ~400–600 mg/day orally to start with lower maintenance dosing (weight-based limits apply); requires baseline & periodic eye exams (retinal toxicity).
  • Sulfasalazine — a sulfa-based DMARD used for both RA and inflammatory bowel disease; see the Sulfasalazine page (GI batch, NG-175) for full dosing/monitoring — same drug, two different disease uses.
  • Anakinra (Kineret) — an IL-1 blocker; do NOT combine with etanercept, adalimumab, or infliximab — combining biologics stacks infection risk without added benefit.
🧠 "Sulfasalazine wears two hats" — one for the gut (IBD) and one for the joints (RA). Same molecule, same sulfa-drug adverse profile either way.
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WATCH FOR

STEP 2 · SAFETY

Immunosuppression is the whole point — and the whole danger. Labs, contraindications, and the drug interaction that raises toxicity.

🚨 Biggest NCLEX trap: WEEKLY, not daily

Methotrexate for RA is prescribed once weekly, on the same day every week. Accidental daily dosing is a real, dangerous, and sometimes fatal medication error — it causes severe bone marrow suppression, GI ulceration, and liver injury.

✅ CORRECT — same day, once a week Mon TUE 💊 Wed Thu Fri Sat Sun ❌ WRONG — daily dosing = toxic Mon 💊 Tue 💊 Wed 💊 Thu 💊 Fri 💊 Sat 💊 Sun 💊 Teach: mark a calendar or set a weekly reminder for the SAME day every week.
🧠 "Methotrexate Monday." Pick one day, say it out loud, put it on the calendar — one dose, seven days apart, every time.

🧪 Labs to monitor

  • CBC — bone marrow suppression → pancytopenia (low WBC, RBC, platelets)
  • LFTs (AST/ALT) — hepatotoxicity; avoid alcohol
  • Renal function — methotrexate is renally cleared; reduced clearance = higher toxicity
🧠 "CLR" — CBC, Liver, Renal — the 3 labs that make methotrexate safe or dangerous.

⚠️ Contraindications

  • Renal insufficiency, liver disease, alcohol abuse, pancytopenia, or folate deficiency → avoid methotrexate
  • Congestive heart failure or neurologic demyelinating disease → avoid etanercept, adalimumab, infliximab
  • Pregnancy — methotrexate is teratogenic; effective contraception required during therapy and for a prescriber-specified period after the last dose (references vary — commonly at least one ovulatory cycle up to 6 months for females and 3 months for males)
🧠 Methotrexate is absolutely contraindicated in pregnancy — it's an abortifacient at higher doses and teratogenic at any dose.

💥 Drug interaction that raises toxicity

Sulfa antibiotics + methotrexate = increased risk of methotrexate toxicity. Both compete for renal clearance and both affect folate metabolism — the combination compounds bone marrow suppression.

🧠 "Sulfa stacks the toxicity." Always ask about antibiotic allergies/current prescriptions before a methotrexate dose.

🦠 Adverse reactions

  • Nausea, stomatitis (mouth sores)
  • Alopecia (hair loss)
  • Sulfasalazine: GI upset, rash/photosensitivity, mild pancytopenia (retinal/ocular toxicity belongs to hydroxychloroquine, not sulfasalazine)
🧠 A sore mouth on methotrexate isn't "just an ulcer" — it's an early toxicity sign. Report it.

🩻 Before starting a biologic: screen first

1️⃣ TB screening — PPD skin test or quantiferon-gold, plus chest X-ray
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2️⃣ Hepatitis B screening
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3️⃣ Only if negative → start the biologic DMARD

Biologics suppress the immune system's ability to keep latent TB contained — starting one in an undiagnosed latent-TB patient can reactivate active disease. Live vaccines are avoided while on any DMARD that suppresses immunity.

🧠 "No jab, no mab." Screen for TB and hep B before the first biologic dose — and hold live vaccines the whole time the patient is on it.
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TEACH

STEP 3 · PATIENT EDUCATION

What she needs to hear before she leaves the room — dosing, folic acid, injections, and when to call.

🍊 Folic acid supplementation — why it's given WITH methotrexate

Methotrexate blocks the folate pathway Folate needed by healthy cells (GI, liver) ✅ Folic acid supplement refills it Overactive immune cells stay suppressed — folic acid doesn't undo the RA benefit Result: fewer GI/mouth/liver side effects, same disease-modifying effect.
🧠 "Folic acid protects the bystanders, not the target." It rescues normal fast-growing cells (gut lining, hair, marrow) from methotrexate's side effects without rescuing the overactive immune cells causing RA.

💉 Self-injection teaching (biologics)

  • Teach proper injection technique and site rotation
  • Have the patient demonstrate the technique before it becomes self-administered
  • Report redness, pain, or swelling at the injection site
  • Teach safe disposal (sharps container)
🧠 Return demonstration before discharge — never assume verbal teaching alone is enough for a subQ self-injection.

📞 Call the provider immediately if...

👄Mouth sores
💧Diarrhea
🌡️Fever
🗣️Sore throat
🩸Easy bruising
🌸Rash / itching
🤢N/V

Any of these can signal bone marrow suppression, infection, or hepatotoxicity — never "wait and see" on methotrexate.

🧠 "No problem is too minor." Even a cold or an open sore can become life-threatening on an immunosuppressant — that instruction line is on the exam.

🗣️ The full teaching bundle

🍊 Take folic acid as ordered 📅 Same day, once weekly 🚫 No alcohol 💊 Ask HCP before ANY OTC drug/supplement 🤰 Effective contraception during + after (per prescriber) 🩺 Report infection s/s immediately 💉 Rotate injection sites 🏃 Continue diet, exercise, PT as prescribed

Treatment for RA is never "just the drug" — explain that management includes drug therapy plus diet, exercise, activity modification, and periodic physical therapy.

🧠 "DMARDs don't work alone." The drug slows the disease; diet, exercise, and PT protect the function that's left.
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QUICK RECALL

SAY IT OUT LOUD
🦠 DMARDs suppress immunity= they slow the disease, not just the pain
🚨 Weekly, never dailymethotrexate dosing error = life-threatening
🍊 Folic acidreduces side effects, keeps the RA benefit
🩻 TB + hep B screenbefore any biologic (-mab/-cept) drug
🎯 Cover & check — 4 rapid-fire questions
Q1: How often is methotrexate dosed for RA?
Once weekly, same day every week — NOT daily. Daily dosing is a dangerous medication error.
Q2: Why is folic acid given with methotrexate?
To reduce GI, mouth, and liver side effects from folate depletion — it doesn't block methotrexate's immunosuppressive/anti-RA effect.
Q3: What must be screened before starting a biologic DMARD (e.g., adalimumab, etanercept)?
TB (PPD/quantiferon + chest X-ray) and hepatitis B — biologics can reactivate latent infections.
Q4: What drug interaction increases methotrexate toxicity?
Sulfa antibiotics — they compete for renal clearance and compound bone marrow suppression.