๐ Common Drugs in Dialysis Patients Dosing ยท Timing ยท Safety
Medications essential for hemodialysis patients: phosphate binders, ESA, vitamin D, antihypertensives, and drugs requiring dose adjustment
Patients with end-stage renal disease on hemodialysis require multiple medications to manage complications of kidney failure. Dosing adjustments, administration timing relative to dialysis, and monitoring for adverse effects are critical. Many drugs are removed by dialysis and require post-dialysis supplementation.
๐ง Phosphate Binders
Purpose: Control hyperphosphatemia (target 3.5โ5.5 mg/dL).
- Calcium acetate (PhosLo, Calcijex): 1โ2 tablets with each meal (max 12โ15 g/day)
- Sevelamer carbonate (Renvela, Renagel): 800โ1600 mg with meals โ non-calcium, also lowers LDL
- Sucroferric oxyhydroxide (Velphoro): 1โ2 chewable tablets with meals (low pill burden)
- Lanthanum carbonate (Fosrenol): 500โ1500 mg with meals โ chewable
โ ๏ธ Critical: Take WITH meals (immediately before or during). Dialysis removes only 30โ40% of dietary phosphorus.
๐ฉธ Erythropoiesis-Stimulating Agents (ESA)
Purpose: Treat anemia (target Hgb 10โ12 g/dL).
- Epoetin alfa (Epogen, Procrit): 50โ150 units/kg IV/SC 3x/week or once weekly
- Darbepoetin alfa (Aranesp): 0.45 ฮผg/kg IV/SC weekly or 0.75 ฮผg/kg every 2 weeks
- Methoxy polyethylene glycol-epoetin beta (Mircera): 0.6 ฮผg/kg IV/SC every 2โ4 weeks
๐ Monitor hemoglobin monthly; adjust dose to avoid Hgb >12 g/dL (increased thrombotic risk). Iron stores must be adequate (ferritin >200 ng/mL, TSAT >20%).
โ๏ธ Vitamin D Analogs (Secondary Hyperparathyroidism)
- Calcitriol (Rocaltrol): 0.25โ0.5 ฮผg IV 3x/week post-dialysis or daily oral
- Paricalcitol (Zemplar): 2โ4 ฮผg IV 3x/week or 1โ2 ฮผg daily oral โ less hypercalcemia
- Doxercalciferol (Hectorol): 4โ8 ฮผg IV 3x/week
๐ Monitor serum calcium, phosphorus, PTH every 1โ3 months. Target PTH 130โ600 pg/mL (KDOQI) or 2โ9x ULN (KDIGO).
โค๏ธ Antihypertensive Medications
Common agents with dialysis considerations:
- Beta-blockers (atenolol, metoprolol, carvedilol): Reduce dose or give post-dialysis (removed by dialysis)
- Calcium channel blockers (amlodipine): No adjustment needed โ not dialyzed
- ACE inhibitors (lisinopril, enalapril): Reduce dose; monitor potassium and BP post-dialysis
- ARBs (losartan, valsartan): Similar to ACE inhibitors
- Clonidine: Avoid giving pre-dialysis (may cause intradialytic hypotension)
๐ Other Essential Medications
- Iron supplementation: IV iron (ferric gluconate, iron sucrose, ferric carboxymaltose) โ 100โ200 mg monthly; oral iron less effective
- Water-soluble vitamins: Nephrocaps, Renavite (B complex + C without vitamin A) โ daily supplement due to dialytic losses
- Cinacalcet (Sensipar): 30โ180 mg daily โ for refractory hyperparathyroidism; monitor calcium
- Insulin: Reduced doses for diabetic patients (12โ24 hours of insulin clearance prolonged); monitor sugars closely
- Heparin: During dialysis sessions (see anticoagulation protocol)
โ ๏ธ Drugs to AVOID or ADJUST in Dialysis
- NSAIDs (ibuprofen, naproxen, ketorolac): Avoid โ GI bleeding risk, reduced renal clearance, fluid retention
- Metformin: Contraindicated if eGFR <30 or dialysis (lactic acidosis risk)
- Lithium: Highly dialyzable โ dose after dialysis, monitor levels
- Magnesium-containing antacids/laxatives: Risk of hypermagnesemia
- Potassium-sparing diuretics (spironolactone, eplerenone): Severe hyperkalemia risk
- Nitrofurantoin: Contraindicated in renal failure โ neurotoxicity
- Colchicine: Reduce dose โ neuromuscular toxicity risk
๐ Dialyzability & Timing of Administration
| Drug | Dialyzability | Timing Recommendation |
|---|---|---|
| Atenolol | High (40-50%) | Give post-dialysis |
| Metoprolol | Low | No adjustment needed |
| Lisinopril | Moderate (25-30%) | Post-dialysis or reduced dose |
| Vancomycin | Low (10-20% per session) | Give post-dialysis; monitor levels |
| Gentamicin / Aminoglycosides | High (40-60%) | Post-dialysis, monitor trough |
| Phenytoin | Low (high protein binding) | No adjustment |
| Warfarin | None | No adjustment; monitor INR |
| Phosphate binders | N/A (not absorbed) | With meals |
| ESA (epoetin, darbepoetin) | None (molecular weight >30kDa) | Any time |
Always verify dialyzability using drug references; timing impacts efficacy and toxicity.
๐งซ Common Antibiotics in Dialysis Patients (Dose Adjustment Required)
| Antibiotic | HD Dose | Post-dialysis Supplement |
|---|---|---|
| Cefazolin | 1-2 g IV after HD | Yes โ 2-3x/week |
| Ceftriaxone | 1-2 g q12-24h | No (long half-life) |
| Cefepime | 1 g q24h | Yes (50% removed) |
| Meropenem | 0.5-1 g q24h | Yes |
| Vancomycin | 15-20 mg/kg load, then 500 mg after each HD | Yes โ monitor trough (15-20 ฮผg/mL) |
| Daptomycin | 4-6 mg/kg after HD | Yes (3x/week) |
| Fluconazole | 400 mg load, then 200 mg after each HD | Yes |
| Acyclovir | 2.5-5 mg/kg after HD | Yes |
๐ง Key Takeaway for Medication Management in Dialysis:
- Phosphate binders must be taken with meals โ patient adherence is the major barrier to phosphorus control.
- ESA and iron therapy require adequate iron stores (ferritin >200, TSAT >20%) for optimal response.
- Antihypertensives that are dialyzable (atenolol, lisinopril) should be given post-dialysis to avoid intradialytic hypotension.
- Water-soluble vitamins are lost during dialysis โ daily renal-specific multivitamin is standard of care.
- Regular medication review by a clinical pharmacist or nephrologist is essential to avoid drug accumulation and toxicity.