How to manage Imdur (isosorbide mononitrate) in patients with hypotension?

From the Guidelines

Imdur should be held in patients with low diastolic pressure, particularly if the systolic blood pressure is less than 90 mm Hg or greater than or equal to 30 mm Hg below baseline, as it can worsen hypotension. In managing Imdur (isosorbide mononitrate) in patients with hypotension, it's crucial to consider the potential for exacerbating low blood pressure due to its vasodilatory effects 1. Key considerations include:

• Avoiding Imdur in patients with systolic blood pressure below 90 mmHg or those with marked bradycardia, tachycardia, or suspected right ventricular infarction, as stated in the ACC/AHA guidelines for the management of patients with ST-elevation myocardial infarction 1.
• Initiating Imdur at a lower dose (e.g., 30 mg once daily) in patients at risk for hypotension and closely monitoring blood pressure, especially during the initial hours after administration.
• Advising patients to take Imdur while seated or lying down to minimize the risk of orthostatic hypotension, to stay well-hydrated, and to avoid alcohol, which can exacerbate hypotensive effects.
• Being prepared to manage hypotension by having the patient lie down with legs elevated and providing fluid resuscitation if necessary.

The mechanism of Imdur, through the release of nitric oxide, reduces preload and afterload, which is beneficial for angina but can cause problematic blood pressure drops in susceptible individuals, such as those on other antihypertensives, with volume depletion, or with autonomic dysfunction 1. Therefore, careful management and monitoring are essential when using Imdur in patients with hypotension.

From the FDA Drug Label

The benefits of ISMN in patients with acute myocardial infarction or congestive heart failure have not been established; because the effects of isosorbide mononitrate are difficult to terminate rapidly, this drug is not recommended in these settings. If isosorbide mononitrate is used in these conditions, careful clinical or hemodynamic monitoring must be used to avoid the hazards of hypotension and tachycardia. Because the hypotension associated with isosorbide mononitrate overdose is the result of venodilatation and arterial hypovolemia, prudent therapy in this situation should be directed toward an increase in central fluid volume.

Imdur Management in Hypotension:

• Hold Imdur: In patients with low diastolic pressure, it is recommended to hold Imdur due to the risk of exacerbating hypotension.
• Monitor: Careful clinical or hemodynamic monitoring is necessary to avoid the hazards of hypotension and tachycardia 2, 2.

From the Research

Management of Imdur in Patients with Hypotension

• Imdur (isosorbide mononitrate) is a nitrate used to prevent angina attacks, but its use in patients with hypotension requires careful consideration.
• Studies have shown that low diastolic blood pressure can be associated with increased risk of cardiovascular events 3, 4.
• In patients with high cardiovascular risk and a treated systolic blood pressure less than 130 mm Hg, a diastolic blood pressure of less than 60 mm Hg was associated with significantly increased risk of cardiovascular events 3.
• Similarly, in patients with heart failure with preserved ejection fraction, a low diastolic blood pressure was found to increase the risks of adverse outcomes 4.
• When using Imdur, it is essential to monitor blood pressure closely, especially in patients with hypotension, as the combination of Imdur with other medications can potentiate hypotensive effects 5.
• The clinical efficacy of Imdur in treating angina pectoris has been demonstrated in several studies 6, 7, but its use in patients with low diastolic blood pressure should be approached with caution.

Considerations for Holding Imdur in Low Diastolic Pressure

• If a patient's diastolic blood pressure is less than 60 mm Hg, it may be necessary to hold Imdur or adjust the dosage to avoid exacerbating hypotension 3, 4.
• The optimal diastolic blood pressure range for patients with high cardiovascular risk is between 70 and 80 mm Hg 3.
• Healthcare providers should carefully weigh the benefits and risks of Imdur therapy in patients with hypotension and consider alternative treatments or dosage adjustments as needed.