From the FDA Drug Label
Severe hypotension, particularly with upright posture, may occur with even small doses of isosorbide dinitrate. This drug should therefore be used with caution in patients who may be volume depleted or who, for whatever reason, are already hypotensive. The benefits of immediate-release oral isosorbide dinitrate in patients with acute myocardial infarction or congestive heart failure have not been established. If one elects to use isosorbide dinitrate in these conditions, careful clinical or hemodynamic monitoring must be used to avoid the hazards of hypotension and tachycardia
Isosorbide dinitrate should not be given with severe hypotension (Diastolic blood pressure of 40 mmHg), as it may exacerbate the condition. The drug label recommends using caution in patients who are already hypotensive, indicating that severe hypotension is a contraindication for the use of isosorbide dinitrate [1] [2].
From the Research
Isosorbide dinitrate should not be given when the diastolic blood pressure is 40 mmHg. This medication is a nitrate vasodilator that works by relaxing blood vessels, which further lowers blood pressure. A diastolic blood pressure of 40 mmHg is already dangerously low and administering isosorbide dinitrate could cause severe hypotension, potentially leading to inadequate organ perfusion, syncope, shock, or even cardiac arrest.
Key Considerations
- The provided studies 3, 4, 5, 6, 7 do not directly address the administration of isosorbide dinitrate in patients with severe hypotension (diastolic blood pressure of 40 mmHg).
- However, the mechanism of action of isosorbide dinitrate as a nitrate vasodilator suggests that it would further lower blood pressure, which is undesirable in a patient with already severely low blood pressure.
- The most recent and highest quality study among the provided options is 4, but it discusses the use of higher than recommended dosages of sublingual isosorbide dinitrate for treating angina pectoris, not its use in severe hypotension.
Clinical Implications
- Patients with such low diastolic pressure require immediate medical attention to identify and treat the underlying cause of hypotension rather than medications that would further reduce their blood pressure.
- If the patient is currently taking isosorbide dinitrate and has developed this level of hypotension, the medication should be withheld and healthcare providers should be notified immediately.
- Blood pressure should be stabilized before considering reintroduction of nitrate therapy, and alternative treatments for the original indication (such as angina or heart failure) may need to be considered.