From the Guidelines
The standard intravenous dosing for famotidine is 20 mg every 12 hours for most adult patients with normal renal function, as recommended in the context of tumor-infiltrating lymphocyte cell therapy 1. For critically ill patients or those with severe GERD or hypersecretory conditions, the dose may be increased to 20 mg every 8 hours or 40 mg every 12 hours.
- Key considerations for famotidine dosing include:
- Renal impairment: For patients with creatinine clearance <50 mL/min, the dose should be reduced to 20 mg every 24 hours or 20 mg every 36-48 hours for severe impairment.
- Administration: Each IV dose should be administered slowly over at least 2 minutes, or it can be diluted in compatible solutions and infused over 15-30 minutes.
- Continuous infusion: Famotidine can be administered at 1.7 mg/hour (approximately 40 mg/24 hours).
- Pediatric dosing: 0.25-0.5 mg/kg every 12 hours, not to exceed adult dosing. Famotidine works by competitively inhibiting histamine H2 receptors on gastric parietal cells, reducing gastric acid secretion, which makes it effective for conditions like peptic ulcers, GERD, and stress ulcer prophylaxis in hospitalized patients, as supported by guidelines for tumor-infiltrating lymphocyte cell therapy 1.
From the FDA Drug Label
DOSAGE & ADMINISTRATION In some hospitalized patients with pathological hypersecretory conditions or intractable ulcers, or in patients who are unable to take oral medication, famotidine injection may be administered until oral therapy can be instituted. The recommended dosage for famotidine injection in adult patients is 20 mg intravenously q 12 h The doses and regimen for parenteral administration in patients with GERD have not been established. Dosage for Pediatric Patients ... The starting dose in pediatric patients 1 to 16 years of age is 0. 25 mg/kg intravenously (injected over a period of not less than two minutes or as a 15 minute infusion) q 12 h up to 40 mg/day. Dosage Adjustments for Patients with Moderate or Severe Renal Insufficiency In adult patients with moderate (creatinine clearance <50 mL/min) or severe (creatinine clearance <10 mL/min) renal insufficiency, the elimination half-life of famotidine is increased For patients with severe renal insufficiency, it may exceed 20 hours, reaching approximately 24 hours in anuric patients Since CNS adverse effects have been reported in patients with moderate and severe renal insufficiency, to avoid excess accumulation of the drug in patients with moderate or severe renal insufficiency, the dose of famotidine injection may be reduced to half the dose, or the dosing interval may be prolonged to 36 to 48 hours as indicated by the patient’s clinical response
The recommended IV dosing of famotidine is:
- Adults: 20 mg intravenously every 12 hours
- Pediatric patients (1-16 years): 0.25 mg/kg intravenously every 12 hours, up to 40 mg/day
- Patients with moderate or severe renal insufficiency: dose may be reduced to half or dosing interval prolonged to 36-48 hours, as indicated by the patient’s clinical response 2
From the Research
Famotidine IV Dosing
- The efficacy of intravenous (IV) famotidine in suppressing gastric secretion has been studied in various clinical trials 3, 4.
- A study published in the Journal of Clinical Pharmacology found that repeated IV boli of famotidine 20 mg every 12 hours allowed for effective control of intragastric acidity in postoperative patients 3.
- Another study published in Critical Care Medicine compared the effects of intermittent administration and continuous infusion of famotidine on gastric pH in critically ill patients, and found that continuous infusion was more effective in maintaining a gastric pH of > or = 4 over a longer time period 4.
- The dosing regimen for famotidine IV varies depending on the clinical context, but common regimens include:
- It is worth noting that the efficacy of famotidine in preventing bleeding in the upper gastrointestinal tract has been compared to other agents, such as pantoprazole, in various studies 5, 6.
- However, the specific dosing regimen for famotidine IV in these studies may not be directly applicable to all clinical situations, and the choice of dosing regimen should be based on individual patient needs and clinical judgment.