336.3 🏥 內科專科考前版

336.3.1 Mechanistic Deep Dive

336.3.1.1 SGLT2i Renal Mechanism

  • Inhibit SGLT2 in PCT → ↓ Na + glucose reabsorption
  • ↑ Distal Na delivery → tubuloglomerular feedback → ↓ glomerular hyperfiltration
  • Reduces intraglomerular pressure
  • Anti-inflammatory + anti-fibrotic
  • Lower renal O2 consumption
  • Independent of glucose lowering

336.3.1.2 Finerenone vs Spironolactone

  • Finerenone: non-steroidal, selective for MR
  • Less hyperkalemia
  • Less anti-androgen effect (gynecomastia, menstrual irregularity)
  • Eplerenone: between (selective steroidal)

336.3.1.3 GLP-1 RA Renal Mechanism

  • ↓ Glomerular hyperfiltration
  • Anti-inflammatory + anti-fibrotic
  • Weight loss → reduces hyperfiltration further
  • CV benefit may also benefit kidney

336.3.1.4 HIF Pathway

  • HIF-α subunits stabilized in hypoxia
  • HIF-PHIs inhibit prolyl hydroxylases → HIF stable
  • ↑ EPO transcription
  • ↓ Hepcidin → improved iron utilization
  • Side effects: thrombotic events, malignancy concerns (long-term unclear)

336.3.2 Recent Trials & Updates

336.3.2.1 FLOW (2024)

  • Semaglutide for T2DM + CKD
  • 24% ↓ composite renal endpoint
  • Extends GLP-1 RA indication

336.3.2.2 DAPA-CKD (2020) + EMPA-KIDNEY (2022)

  • Extended SGLT2i to non-DM CKD
  • Foundation for broader use

336.3.2.3 ASCEND-D + ASCEND-ND (2021)

  • Daprodustat in dialysis + non-dialysis
  • FDA approval 2023
  • Non-inferior to ESAs

336.3.2.4 PYRAMID, PROTECT (2024)

  • Sparsentan for IgA + FSGS
  • Endothelin antagonist combined ARB

336.3.2.5 APPLAUSE-IgAN (Ongoing)

  • Iptacopan in IgA

336.3.2.6 AMPLITUDE (Ongoing)

  • Inaxaplin for APOL1 nephropathy

336.3.2.7 EMPATHY (Ongoing)

  • Empagliflozin in earlier CKD

336.3.3 High-Yield Specialist Points

336.3.3.1 Starting + Continuing SGLT2i

  • Start at any eGFR ≥ 20-25 (drug-specific)
  • Initial 30% Cr ↑ acceptable, indicates working
  • Continue down to dialysis (real-world)
  • Hold during acute illness, surgery (euglycemic DKA risk)

336.3.3.2 Starting Finerenone

  • eGFR ≥ 25
  • K ≀ 4.8 to initiate
  • Monitor K within 4 weeks
  • Titrate from 10 to 20 mg

336.3.3.3 Combining 4 Pillars

  • Multidisciplinary management
  • Stepwise initiation (not all at once if multiple high-risk)
  • Monitor: BP, K, Cr, weight
  • Adjust as needed

336.3.3.4 GLP-1 RA Practical

  • Subcutaneous injection (most)
  • Oral semaglutide (Rybelsus) available
  • Once weekly preferred (semaglutide, dulaglutide)
  • GI side effects (nausea); tirzepatide has more
  • Pancreatitis caution

336.3.3.5 Iron Repletion Strategies

  • Oral: ferrous sulfate 325 mg BID-TID
  • IV iron: faster repletion, common in HD
  • Hepcidin → blunted oral absorption in CKD

336.3.3.6 ESAs Practical

  • Subcutaneous monthly (darbepoetin) or weekly (epoetin)
  • HD: post-dialysis
  • Target Hgb 10-11.5 (don’t normalize)
  • Watch for CV events at higher Hgb (CHOIR, TREAT)

336.3.3.7 HIF-PHI Selection

  • Oral advantage (vs injection)
  • Effective at lower hemoglobin levels
  • Side effects: thrombotic, BP, possible CV
  • Long-term data evolving

336.3.3.8 Vascular Calcification Management

  • Phosphate control
  • Avoid excess Ca
  • Vitamin K (controversial)
  • Tenapanor (Na-H exchanger inhibitor in gut) — for hyperphosphatemia

336.3.3.9 Aminoglycoside Avoidance

  • Especially in CKD
  • Alternative antibiotics
  • Risk of acute decline

336.3.3.10 Polypharmacy Management

  • Many CKD patients on 10+ medications
  • Regular medication review
  • Pharmacist involvement
  • Deprescribing when appropriate

336.3.3.11 CKD + Pregnancy

  • Pre-conception counseling
  • Higher risk (preeclampsia, IUGR, prematurity)
  • Avoid ACE/ARB/MRA in pregnancy
  • LMWH for clotting
  • Multidisciplinary team

336.3.3.12 Patient + Family Education

  • CKD as chronic condition
  • Lifestyle modification
  • Drug interactions
  • Vaccinations (flu, pneumococcal, COVID, RSV ≥ 60)
  • Mental health
  • Treatment options for ESKD

336.3.3.13 Conservative Management Option

  • For elderly, multimorbid, dialysis-refusing
  • Kidney supportive care
  • Symptom management
  • Quality of life focus

336.3.4 Pearls

  • 4 pillars CKD treatment: ACE/ARB + SGLT2i + finerenone + GLP-1 RA
  • HIF-PHI new for renal anemia
  • Non-Ca phosphate binders preferred (vascular calcification)
  • Patiromer + SZC for chronic hyperkalemia
  • Sodium bicarbonate for acidosis (target HCO3 22-26)
  • Statin in albuminuric CKD + age + ASCVD risk
  • Emerging: sparsentan, iptacopan, inaxaplin
  • Conservative care option for select advanced