What is the most appropriate additional therapy for a 63-year-old man with gastroesophageal reflux disease (GERD), stage G4 chronic kidney disease (CKD), obesity, and hypertension, who is taking atenolol, lisinopril, and nifedipine, and has Impaired renal function with an estimated glomerular filtration rate (eGFR) indicating severe renal impairment?

From the Guidelines

The most appropriate additional therapy for this patient is famotidine (option A). This H2-receptor antagonist is preferred for managing gastroesophageal reflux disease (GERD) in patients with advanced chronic kidney disease. Unlike proton pump inhibitors like omeprazole, famotidine has less potential for adverse effects in patients with renal impairment and fewer drug interactions with the patient's current medications, such as atenolol, lisinopril, and nifedipine 1. The patient's stage G4 chronic kidney disease (eGFR 29 mL/min/1.73 m²) makes renal clearance a significant concern, as highlighted in the management of diabetes in chronic kidney disease 1. Omeprazole should be avoided due to potential nephrotoxicity and drug interactions. Calcium carbonate and magnesium hydroxide are problematic because magnesium can accumulate in renal failure, potentially causing toxicity. Sucralfate contains aluminum which can also accumulate in kidney disease and may cause constipation, further complicating the patient's condition. Famotidine can be dosed appropriately for renal function and provides effective acid suppression for GERD symptoms while maintaining a favorable safety profile in this patient with multiple comorbidities, including obesity and hypertension.

Some key considerations in this patient's management include:

• The importance of monitoring renal function and adjusting medication doses accordingly, as seen in the management of diabetes in chronic kidney disease 1
• The need to avoid medications that may exacerbate renal impairment or interact with the patient's current medications, such as those highlighted in the guideline for the prevention, detection, evaluation, and management of high blood pressure in adults 1
• The benefits of using medications with a favorable safety profile in patients with multiple comorbidities, such as famotidine in this case.

Overall, the choice of famotidine as the most appropriate additional therapy for this patient is based on its efficacy in managing GERD symptoms, its safety profile in patients with advanced chronic kidney disease, and its minimal potential for adverse effects and drug interactions.

From the FDA Drug Label

1. 2 Dosage in Renal Impairment Dosage adjustments of Famotidine are recommended for patients with moderate to severe renal impairment (creatinine clearance less than 60 mL/min) Table 2 shows the recommended maximum dosage of Famotidine 20 mg or 40 mg tablets for patients with renal impairment, by indication. Use the lowest effective dose. Some dosage adjustments may require switching to other formulations of famotidine (e.g., oral suspension, lower dose tablet) Indication Creatinine clearence 30 to 60mL/minute Creatinine clearence less than 30 mL/minute Symptomatic non-erosive GERD 20mg once daily 20mg every other day

The most appropriate additional therapy for the patient with stage G4 chronic kidney disease and symptomatic non-erosive GERD is Famotidine at a dose of 20mg every other day 2.

• Key points:
  • The patient has severe renal impairment with an estimated glomerular filtration rate of 29 mL/min/1.73 m2.
  • Famotidine dosage needs to be adjusted in patients with moderate to severe renal impairment.
  • The recommended dose for symptomatic non-erosive GERD in patients with creatinine clearance less than 30 mL/minute is 20mg every other day.
• Main consideration: Renal impairment requires dosage adjustment of Famotidine to prevent potential adverse effects.

From the Research

Treatment Options for Gastroesophageal Reflux Disease (GERD)

The patient's symptoms of GERD, including heartburn and worsening symptoms after large meals and when lying down, can be managed with various treatment options. Considering the patient's stage G4 chronic kidney disease, obesity, and hypertension, the choice of medication is crucial.

Proton Pump Inhibitors (PPIs) as a Treatment Option

• PPIs, such as omeprazole, are effective in treating GERD and erosive esophagitis, as shown in studies 3, 4, 5, 6.
• Omeprazole has been recommended as an over-the-counter treatment for heartburn in patients with at least two episodes of heartburn per week 3.
• A study comparing vonoprazan with PPIs, including omeprazole, found that vonoprazan had a higher healing effect for patients with severe esophagitis, but not for those with mild esophagitis 7.

Suitable Treatment for the Patient

• Given the patient's symptoms and medical history, omeprazole (Option B) is a suitable treatment option, as it is effective in treating GERD and has been shown to be safe and well-tolerated in various studies 3, 4, 5, 6.
• The patient's estimated glomerular filtration rate (eGFR) of 29 mL/min/1.73 m2 indicates stage G4 chronic kidney disease, but there is no evidence to suggest that omeprazole is contraindicated in patients with chronic kidney disease.
• Famotidine (Option A) is an H2 receptor antagonist, which may not be as effective as PPIs in treating GERD.
• Oral calcium carbonate and magnesium hydroxide (Option C) are antacids that can provide quick relief for heartburn, but may not be suitable for long-term management of GERD.
• Sucralfate (Option D) is a medication that forms a protective barrier over ulcers, but it may not be as effective as PPIs in treating GERD.