II. Background
- Drug adjustments based on GFR
-
Glomerular Filtration Rate (GFR) evaluation
- 24 Hour Urine Creatinine Clearance (Gold Standard)
- Estimates
- Cockcroft-Gault Equation (CG)
- Modification of Diet in Renal Disease (MDRD)
- More accurate than CG when GFR <60 ml/min/1.73 m2
- Interpretation of GFR (dosing is based on 3 categories)
- Glomerular Filtration Rate <10 ml/min/1.73 m2
- Glomerular Filtration Rate <10-50 ml/min/1.73 m2
- Glomerular Filtration Rate >50 ml/min/1.73 m2
III. Precautions: General
- Loading doses require no renal dose adjustment
- For patients on renal replacement
- Dialyzed medications should be taken after Hemodialysis run for the day
- Peritoneal Dialysis does not affect the timing of medications
- For patients on Phosphate Binders
- Take medications (esp. Antibiotics) one hour before or 3 hours after Phosphate Binder dose
- Maintenance doses can be adjusted in 2 ways
- Reduce each dose, but maintain same dose interval
- Risks toxicity due to drug accumulation
- Maintain same dose, but lengthen dosing interval
- Risks sub-therapeutic dosing
- Reduce each dose, but maintain same dose interval
IV. Precautions: Antihypertensives
- Loop Diuretics (e.g. Lasix) are preferred in CRF
-
ACE Inhibitors or Angiotensin Receptor Blockers (ARB)
- Preferred agents in CRF (renal and cardioprotective)
- Starting dose
- Moderate dose in most patients (e.g. Lisinopril 10-20 mg daily)
- Lower dose with severe Chronic Kidney Disease, CHF or age over 80 years
- Anticipate a 15% increase in Serum Creatinine in week 1
- Level usually returns to baseline by 4-6 weeks
- Monitoring
- Parameters
- Baseline
- Week 1-2 after each dose change, then
- Week 2-3 after each dose change, then
- Every 6-12 months
- Abnormal labs requiring medication change
- Criteria
- Serum Creatinine rises >30% above baseline
- Serum Potassium >5.5 mEq/L
- Approach
- Decrease ACE Inhibitor or ARB to half dose and recheck labs in 1-2 weeks
- Decrease Diuretic doses if Serum Creatinine increased
- Eliminate Medication Causes of Elevated Serum Potassium
- Indications to stop ACE Inhibitor or ARB
- Serum Creatinine remains >30% despite changes OR
- Serum Potassium >5.5 mEq/L despite changes
- Criteria
- References
- (2014) Presc Lett 21(6): 31
-
Thiazide Diuretics
- Avoid if Serum Creatinine >2.5 mg/dl
- Avoid if Creatinine Clearance <30 ml/min/1.73 m2
- Loop Diuretics are more effective with reduced GFR
-
Potassium-Sparing Diuretics or Aldosterone blockers
- Avoid in severe Chronic Kidney Disease (Hyperkalemia)
-
Beta Blockers
- Hydrophilic Beta Blockers require renal adjustment
- Examples: Atenolol, Bisoprolol, Nadolol, Acebutolol
- Beta Blockers not requiring renal dose adjustment
- Metoprolol Tartrate (Lopressor), Succinate (Toprol)
- Propranolol (Inderal)
- Labetolol
- Atenolol
- Reduce to 50% if GFR<50 ml/min
- Reduce to 25% if GFR<10 ml/min
- Hydrophilic Beta Blockers require renal adjustment
- Other agents NOT requiring renal dose adjustment
- Calcium Channel Blockers
- Clonidine
- Alpha blockers
V. Precautions: AntiHyperlipidemics
- Atorvastatin (Lipitor) requires no dosage adjustment
-
Simvastatin (Zocor) requires minimal dose adjustment
- Start at 5 mg if GFR <30 ml/min
-
Rosuvastatin (Crestor)
- Start at 5 mg and do not exceed 10 mg if GFR <30 ml/min
- Lescol, Pravachol, Crestor adjusted if GFR <30 ml/min
- Lovastatin (Mevacor) avoided if GFR <30 ml/min
VI. Precautions: Hypoglycemics (Diabetes Mellitus)
-
Metformin (Glucophage): Risk of Lactic Acidosis in CRF
- Avoid when Serum Creatinine >1.5 mg/dl in men
- Avoid when Serum Creatinine >1.4 mg/dl in women
- Avoid in age over 80 years or chronic Heart Failure
-
Sulfonylureas: Risk of Hypoglycemia in CRF
- Glipizide is safe to use in CRF
- Avoid Glyburide, Chlorpropamide if GFR <60 ml/min
VII. Precautions: Antibiotics
- Antibiotics that require NO renal dose adjustment
- Agents to avoid in severe Chronic Kidney Disease
- Penicillin G (Myoclonus, Seizures, coma risk)
- Imipenem with cilastin (Seizure risk); Meropenem safe
- Tetracycline (exacerbates Uremia); Doxycycline safe
- Nitrofurantoin (peripheral neurotoxicity)
- Aminoglycosides (or close level monitoring if used)
-
Amoxicillin
- Reduce to every 24 hours if GFR<10 ml/min
-
Augmentin
- Reduce to every 24 hours if GFR<10 ml/min
- Do not use Augmentin 875/125 mg tabs if GFR<30 ml/min
-
Cefazolin
- Reduce to every 12 hours if GFR<50 ml/min
- Reduce to 50% every 24-48 hours if GFR<10 ml/min
-
Cefuroxime
- Reduce to 250 to 500 mg every 24 hours if GFR<10 ml/min
-
Cephalexin
- Reduce to every 12-24 hours if GFR<10 ml/min
-
Ciprofloxacin
- Reduce dose to 50-75% if GFR<50 ml/min
- Reduce dose to 50% or change to once daily dosing if GFR<10 ml/min
-
Clarithromycin
- Reduce dose to 50-100% if GFR<50 ml/min
- Reduce dose to 50% or change to once daily dosing if GFR<10 ml/min
-
Penicillin
- Reduce to 50% if GFR <30 ml/min
-
Levofloxacin
- Reduce to every 24-48 hours if GFR<50 ml/min (or 500 mg loading dose, then 250 mg for subsequent doses)
- Reduce to every 48 hours if GFR<20 ml/min
- Avoid if GFR<10 ml/min
- Trimethoprim-Sulfamethoxazole (TMP-SMZ, Septra, Bactrim)
- Reduce to 50% if GFR <30 ml/min
- Avoid if GFR<15 ml/min
-
Vancomycin
- Adjust dosing intervals based on drug level and Creatinine Clearance
VIII. Precautions: Antivirals
-
Acyclovir oral
- Reduce to 200 mg every 12 hours if GFR<10 ml/min
-
Valacyclovir
- Reduce to every 12-24 hours if GFR<50 ml/min
- Reduce to 500mg every 24 hours if GFR<10 ml/min
-
Ganciclovir
- Renal Dosing adjustment is needed for GFR <70 ml/min
IX. Prcautions: Antfungals
-
Fluconazole
- Reduce to 50% if GFR<50 ml/min
X. Precautions: Analgesics
- Acetaminophen is safe in CRF
- Safest Opioid Analgesics (gastrointestinal excretion)
- Agents to use with caution
- Hydromorphone (Dilaudid)
- Oxycodone (Roxicodone)
- Tramadol (Ultram)
- Do not exceed 50-100 mg twice daily
- Agents to avoid in severe CRF (GFR <30 ml/min)
- Agents to avoid in severe CRF (GFR <30 ml/min) that are typically avoided for other risks (listed for historical reasons)
- Agents to avoid at any level of CRF or risk of CRF
- NSAIDS (repeat Serum Creatinine q2 weeks if used)
- COX-2 Inhibitors
XI. Precautions: Neuropsychiatric agents
- Avoid Tricyclic Antidepressants in Chronic Kidney Disease
- Risk of Arrhythmia
- Gabapentin (Neurontin)
-
Pregabalin (Lyrica)
- Requires decreased dosage at an increased frequency
-
Lamotrigine
- May require renal dose adjustment
-
Lithium
- Requires renal dose adjustment
XII. Precautions: Gastrointestinal Agents
- Avoid phosphate and Magnesium containing Laxatives or enemas
- Avoid Magnesium containing Laxatives (e.g. Milk of Magnesia, Magnesium Citrate)
- Risk of Hypermagnesemia
- Avoid phosphate containing enemas (e.g. Fleets Enema)
- Risk of Hyperphosphatemia
- Avoid Magnesium containing Laxatives (e.g. Milk of Magnesia, Magnesium Citrate)
-
Famotidine (Pepcid)
- Reduce to 50% if GFR<60 ml/min
- Reduce to 25% if GFR<50 ml/min
- Reduce to 10% if GFR<10 ml/min
-
Ranitidine (Zantac)
- Reduce to 75% if GFR<60 ml/min
- Reduce to 50% if GFR<50 ml/min
- Reduce to 25% if GFR<10 ml/min