From the FDA Drug Label
DOSAGE AND ADMINISTRATION Exertional Angina Pectoris Due to Atherosclerotic Coronary Artery Disease or Angina Pectoris at Rest Due to Coronary Artery Spasm: Dosage must be adjusted to each patient’s needs Starting with 30 mg four times daily, before meals and at bedtime, dosage should be increased gradually (given in divided doses three or four times daily) at 1- to 2-day intervals until optimum response is obtained. Although individual patients may respond to any dosage level, the average optimum dosage range appears to be 180 to 360 mg/day
The maximum dose of diltiazem a person can receive in 6 hours is not explicitly stated in the provided drug labels. However, based on the average optimum dosage range of 180 to 360 mg/day, we can estimate the maximum dose for 6 hours.
- Assuming a uniform distribution of the daily dose, the maximum dose per 6 hours would be 180-360 mg / 4 = 45-90 mg per 6 hours, considering the drug is given in divided doses three or four times daily.
- However, since the question asks for the maximum dose in 6 hours and the labels do not provide a clear maximum dose for this timeframe, the maximum dose cannot be determined with certainty.
- Given the information provided and to err on the side of caution, the dose should not exceed the estimated maximum dose per 6 hours, but the exact value cannot be determined from the provided labels 1.
From the Research
The maximum dose of diltiazem that can be safely administered over 6 hours is not explicitly stated in the provided studies, but according to the most recent and highest quality study, a dose of 0.13 mg/kg or less is recommended to minimize the risk of hypotension 2.
Diltiazem Dosing Considerations
When considering the administration of diltiazem, it is essential to take into account the patient's medical condition, weight, and other factors that may influence the medication's efficacy and safety. The studies provided suggest that diltiazem is effective in controlling rapid atrial fibrillation, but the optimal dosing strategy is still a topic of debate.
Key Findings
- A study published in 2021 found that a diltiazem bolus dose of 0.13 mg/kg or more was associated with improved heart rate control compared to a dose of less than 0.13 mg/kg 2.
- Another study published in 2011 found that low-dose diltiazem (≤ 0.2 mg/kg) was as effective as the standard dose in controlling rapid atrial fibrillation and reduced the risk of hypotension 3.
- A 2022 study comparing intravenous metoprolol and diltiazem for rate control in atrial fibrillation found no significant difference in the achievement of rate control between the two medications 4.
Recommendations
Based on the available evidence, it is recommended to start with a low dose of diltiazem (0.13 mg/kg or less) and titrate as needed to achieve the desired heart rate control while minimizing the risk of hypotension. However, the maximum dose of diltiazem that can be safely administered over 6 hours is not explicitly stated in the provided studies, and therefore, it is crucial to consult with a licensed healthcare provider to determine the appropriate dosing strategy for each individual patient.
Important Considerations
- Diltiazem can cause hypotension, and the risk of hypotension increases with higher doses 3, 2.
- The medication should be administered with caution in patients with certain medical conditions, such as heart failure or bradycardia.
- Patients should be closely monitored for signs of hypotension, bradycardia, and other adverse effects during and after diltiazem administration.