From the Guidelines
Imdur (Isosorbide mononitrate) has a half-life of approximately 4 to 5 hours. This information is based on the study by Abrams, as summarized in the acc/aha guidelines for the management of patients with acute myocardial infarction 1. The half-life of a drug is an important factor in determining its dosing frequency and therapeutic effects. In the case of Imdur, its half-life of 4 to 5 hours allows for sustained-release formulations to provide prolonged therapeutic effects.
Key points to consider about Imdur include:
- It is a synthetic nitrate approved by the FDA in 1991
- It does not undergo hepatic metabolism and is 100% bioavailable after oral dosing
- It is available in sustained-release formulas, which allows for once-daily dosing
- It works as a nitrate vasodilator to relax blood vessels, improve blood flow, and reduce the workload on the heart
As noted in the guidelines 1, Imdur is effective for treating angina (chest pain) and other cardiovascular conditions. Patients should take Imdur in the morning to maintain therapeutic levels throughout the day while allowing for a nitrate-free period overnight, which helps prevent tolerance to the medication. It is essential to take Imdur exactly as prescribed and not to suddenly stop the medication, as this could worsen the condition.
From the FDA Drug Label
The mean plasma elimination half-life of ISMN is approximately 5 hours. The half-life of Imdur (Isosorbide mononitrate) is approximately 5 hours 2.
From the Research
Half-Life of Imdur (Isosorbide Mononitrate)
- The half-life of Isosorbide mononitrate is approximately 4 hours 3, 4.
- Another study found the terminal half-life to be 4.1 and 4.6 hours after oral and intravenous administration, respectively 3.
- A study comparing the pharmacokinetics of an extended-release tablet formulation of Isosorbide-5-mononitrate with a standard dinitrate formulation found the mean plasma apparent elimination half-life of 5-ISMN to be 6.2 hours after extended-release administration and 7.1 hours after ISDN administration 5.
- The half-life of Isosorbide mononitrate allows for once-daily administration, providing effective prophylaxis of symptoms throughout the day 6.