Protamine

Protamine

[1 vial $8.54]

ADMINISTRATION ROUTES:

  • IV

ALTERNATIVE NAMES:

  • Protamine

ICU INDICATIONS:

  1. reversal of heparin

PRESENTATION AND ADMINISTRATION:

  • IV:
    50mg in 5ml (solution).
    Administer by slow IV injection over no greater than 1ml/minute (i.e. 50mg over 5 minutes).
    Watch the blood pressure trace closely during administration and slow rate of infusion if the blood pressure drops.
    Administration by IV infusion is described but is not generally preferred.
    To administer by IV infusion, add to a suitable volume of compatible IV fluid and administer over required time period
    Compatible with the following IV fluids:
    0.9% sodium chloride, 5% dextrose, glucose and sodium chloride
    Store at room temperature.
    Protect from light.

DOSAGE:

  • IV:
    For neutralisation of unfractionated heparin:
    1mg of protamine sulphate will usually neutralise at least 100 international units of mucous heparin or 80 units of lung heparin.
    The dose of protamine sulphate should be reduced if more than 15 minutes have elapsed since intravenous injection.
    For example, if 30-60 minutes have elapsed since heparin was injected intravenously, 0.5-0.75mg protamine sulphate per 100 units of mucous heparin is recommended. If two hours or more have elapsed, 0.25-0.375mg per 100 units of mucous heparin should be administered.
    If the patient is receiving an intravenous infusion of heparin, the infusion should be stopped and 25-50mg of protamine sulphate given by slow intravenous injection.
    In the reversal of UF heparin following cardiopulmonary bypass, either a standard dose of protamine may be given, as above, or the dose may be titrated according to the activated clotting time or TEG.
    Neutralisation of low molecular weight (LMW) heparin:

    A dose of 1mg per 100 units is usually recommended.
    The anti-Xa activity of LMW heparins may not be completely reversible with protamine sulphate and may persist for up to 24 hours after administration.
    The longer half-life of LMW heparins (approximately twice that of UF heparin) should also be borne in mind when estimating the dose of protamine sulphate required in relation to the time which has elapsed since the last heparin dose. Theoretically, the dose of protamine sulphate should be halved when one half-life has elapsed since the last LMW heparin dose.
    Intermittent injections or continuous infusion of protamine sulphate have been recommended for the neutralisation of LMW heparin following subcutaneous administration, as there may be continuing absorption from the subcutaneous depot.

DOSAGE IN RENAL FAILURE AND RENAL REPLACEMENT THERAPY:

  • Dose as in normal renal function

DOSAGE IN PAEDIATRICS:

  • IV:
    1mg/100 IU of heparin (0.5mg/100 IU of heparin if > 1 hour since heparin dose); subsequent doses of protamine 1mg/kg (max 50mg)

CLINICAL PHARMACOLOGY:

  • Protamine is used to counteract the anticoagulant effect of heparin through the formation of heparin-protamine complexes. The onset of action of protamine occurs within five minutes following intravenous administration. The fate of the protamine-heparin complex is unknown, but it may be partially degraded, thus freeing heparin.

CONTRAINDICATIONS:

  1. hypersensitivity to protamine

WARNINGS

  • Hypotension:
    Rapid administration of protamine may lead to severe hypotension and anaphylactoid reactions

PRECAUTIONS

  • General:
    In patients who have had cardiac surgery with cardiopulmonary bypass, a rebound bleeding effect may occur hours post-operatively. This responds to further doses of protamine.
  • Laboratory Tests: No tests in addition to routine ICU tests are required
  • Drug/Laboratory Test Interactions: None known

IMPORTANT DRUG INTERACTIONS FOR THE ICU

  • None known

ADVERSE REACTIONS

  • Body as a Whole:
    Anaphylaxis, angioedema
  • Cardiovascular System:
    Hypotension, flushing
  • Respiratory System:
    Non cardiogenic pulmonary oedema
  • Digestive System:
    Nausea, vomiting

Critical Care Drug Manual

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