What are the appropriate anticipatory medications and their doses for a patient with impaired renal function?

From the Guidelines

For patients with impaired renal function, it is crucial to adjust the doses of anticipatory medications to prevent toxicity, and the choice of medication should be guided by the severity of renal impairment and the medication's pharmacokinetics. When managing patients with impaired renal function, the goal is to minimize the risk of medication-induced morbidity and mortality while maintaining quality of life.

Key Considerations

• The severity of renal impairment, often estimated by the creatinine clearance (CrCl) rate, plays a significant role in determining the appropriate dose adjustments for medications that are primarily cleared by the kidneys.
• Medications such as Simvastatina require careful dosing in patients with severe renal failure (CrCl < 30 mL/min), with recommendations to start with low doses, such as 10 mg 1.
• Ramiprila, an ACE inhibitor, necessitates dose adaptation if CrCl < 30 mL/min, with an initial dose of 1.25 mg daily and a maximum dose not exceeding 5 mg/day 1.
• Losartana, used for hypertension or renal failure in type 2 diabetes with microalbuminuria, is recommended at doses of 50–100 mg/day, with regular monitoring of electrolyte balance and serum creatinine 1.
• For anticoagulants like Enoxaparina, severe renal failure (CrCl < 30 mL/min) may require dose adjustment or contraindication, depending on country-specific labeling 1, while Fondaparinux is contraindicated in severe renal failure but might be considered due to its lower risk of bleeding complications compared to enoxaparin 1.
• Bivalirudin dosing should be adjusted in patients with CrCl < 30 mL/min, considering a reduction of the infusion rate to 1.0 mg/kg/h, and further reduced to 0.25 mg/kg/h if the patient is on hemodialysis, without needing a reduction in the bolus dose 1.
• Tirofiban and Eptifibatide require dose adaptations in renal failure; for Tirofiban, 50% of the dose is recommended if CrCl < 30 mL/min, and for Eptifibatide, the infusion dose should be reduced to 1 mg/kg/min if CrCl < 50 mL/min, with the drug being contraindicated if CrCl < 30 mL/min 1.
• Atenolol dosing should be halved for patients with CrCl between 15 and 35 mL/min (50 mg/day) and quartered (25 mg/day) if CrCl < 15 mL/min 1.

Medication Selection and Dose Adjustment

• Simvastatina: 10 mg in severe renal failure.
• Ramiprila: Initial dose 1.25 mg daily, maximum 5 mg/day in CrCl < 30 mL/min.
• Losartana: 50–100 mg/day with monitoring.
• Enoxaparina: Adjust dose or contraindicate in severe renal failure.
• Fondaparinux: Contraindicated in severe renal failure but may be considered for lower bleeding risk.
• Bivalirudin: Adjust infusion rate in renal impairment.
• Tirofiban: 50% dose reduction if CrCl < 30 mL/min.
• Eptifibatide: Reduce infusion dose if CrCl < 50 mL/min, contraindicated if CrCl < 30 mL/min.
• Atenolol: Half dose for CrCl 15-35 mL/min, quarter dose if CrCl < 15 mL/min.

Given the complexity of managing medications in patients with impaired renal function, it is essential to consult the most recent guidelines and drug labeling for specific recommendations, as the pharmacokinetics of drugs can vary significantly in the context of renal impairment 1.

From the FDA Drug Label

Use in Patients with Renal or Hepatic Impairment Since metoclopramide is excreted principally through the kidneys, in those patients whose creatinine clearance is below 40 mL/min, therapy should be initiated at approximately one-half the recommended dosage.

• Metoclopramide: For patients with impaired renal function (creatinine clearance below 40 mL/min), the recommended dosage is approximately one-half the recommended dosage.
• Ondansetron: No dosage adjustment is recommended for patients with any degree of renal impairment (mild, moderate, or severe) 2. The appropriate anticipatory medication for a patient with impaired renal function is metoclopramide, with a dose of approximately one-half the recommended dosage, and ondansetron with no dosage adjustment. 3 2

From the Research

Anticipatory Medications for Impaired Renal Function

The following medications and their doses may be considered for patients with impaired renal function:

• Pantoprazole: The standard dose of 40 mg can be used with confidence in patients with chronic renal impairment, as its bioavailability is not altered in these patients 4.
• Corticosteroids: Prednisone doses of 1 mg/kg/d have been suggested for the treatment of drug-induced acute interstitial nephritis (AIN) 5.

Considerations for Patients with Impaired Renal Function

When evaluating patients with impaired renal function, the following factors should be considered:

• Serum creatinine levels: A serum creatinine > or =2.0 mg/dL is associated with a significantly increased likelihood of death in injured patients 6.
• Renal monitoring: Monitoring renal function is vital to the safe administration of therapeutic agents, especially in patients with cancer 7.
• Dose adjustment: Dose adjustment may not be required for pantoprazole in patients with chronic renal impairment, but other medications may require dose adjustment based on renal function 4.

Potential Nephrotoxic Agents

The following agents may be nephrotoxic and require careful consideration in patients with impaired renal function:

• Chemotherapy agents
• Molecular targeted agents
• Pain management agents
• Radiopharmaceuticals
• Contrast agents used in radiology
• Antiresorptive agents 7