Tuesday, December 8, 2015

Elantan to Imdur conversion (SR isosorbide mononitrate)


Availability:
  • Elantan Long 50mg [ sustained release]
  • Imdur 60mg
Rationale for ISMN
  •  Most patients are maintained on a modified release (MR) preparation which is usually taken once daily in the morning to maintain a nitrate-low period and thus minimise tolerance.
  •  ISMN is preferred over isosorbide dinitrate as isosorbide dinitrate requires more frequent dosing
  • Compliance has been shown to improve when transferring from multiple dose regimens to once-daily regimens.
  • The low plasma nitrate level at 24 hours following ingestion appears to minimise tolerance
Bioequivalence
  • no published comparative studies of asymmetric dosing of plain isosorbide mononitrate with the slow-release form that inform dose equivalence.
  • Limited data exists regarding switching from normal release to MR tablets but initially a mg per mg substitution would be appropriate (i.e. same daily dose overall) in most patients, and where available formulations allow.
  • Because information on the dose equivalence of these products is uncertain, clinical oversight to consider further dose adjustment may be required
  • There is significant cost variation between the ISMN MR products available and the product of lowest cost should be provided
Conversion
  • Most patients can be changed initially on a mg per mg substitution of their total daily dose (i.e. same daily dose overall) where available formulations allow
  • If changing between preparations results in an overall increase in daily ISMN dose, patients should be advised that they might experience a nitrate headache for a few days after conversion or potential drop in postural BP
Immediate Release
10mg tablet
Elantan Long
25/50mg Capsule
Imdur
30/60mg Tab
10mg BD
25mg OD
30mg OD
20mg BD
50mg OD
60mg OD
30mg BD

60mg OD
90mg OD
40mg BD
100mg OD
120mg OD
*Underlined- available strength at hospital
References:
  1. Isosorbide Mononitrate (ISMN) Prescribing. NHS PrescQIPP, Buletin 85, November 2014.
  2. PRESCRIBING SUPPORT TEAM AUDIT: ISOSORBIDE MONONITRATE. NHS Dumfires and Galloway, 2009.
  3. Isosorbide Mononitrate – Briefing paper for GPs/Nurses

2 comments:

  1. Imdur (Isosorbide mononitrate) is used to prevent chest pain (angina) in patients with a certain heart condition (coronary artery disease). This medication belongs to a class of drugs known as nitrates. It works by relaxing and widening blood vessels so blood can flow more easily to the heart. This medication will not relieve chest pain once it occurs. Also, it is not intended to be taken just before physical activities (such as exercise or sexual intercourse) to prevent chest pain.

    ReplyDelete
    Replies
    1. thank you for the additional input, we truly appreciate your time and efforts.

      have a great day ahead

      Delete

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