Digoxin immune fab

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Digoxin immune fab
Digibind.jpg
Bottle of digoxin immune fab
Names
Trade namesDigibind, DigiFab, others
Other namesDigoxin-specific antibody
  • Anti-digoxin antibody fragment
Clinical data
Main usesDigoxin toxicity[1]
Side effectsLow potassium, heart failure, allergic reaction[1]
Pregnancy
category
  • US: C (Risk not ruled out)
Routes of
use
IV infusion, injection
Onset of action30 min[2]
Duration of action15 to 20 hrs[2]
External links
AHFS/Drugs.comMonograph
Pharmacokinetics
Elimination half-life15 hours for DigiFab, 23 hours for Digibind
ExcretionKidney
Chemical and physical data
FormulaC2085H3223N553O672S16
Molar mass47301.88 g·mol−1
 ☒NcheckY (what is this?)  (verify)

Digoxin immune fab, sold under the brand name Digibind among others, is the antidote for digoxin toxicity.[1] It may also be used for toxicity from certain plants such as oleander or foxglove and for eclampsia.[1] It is given by injection into a vein.[1] Benefits occur within 30 minutes.[1]

Common side effects include low potassium and heart failure.[1] Other side effects may include allergic reactions including anaphylaxis.[1] When needed, it can be used during pregnancy or breastfeeding.[3] It works by binding to digoxin and similar compounds in the blood.[1]

Digoxin immune fab was approved for medical use in the United States in 1986.[4] In the United Kingdom one 40 mg vial cost the NHS about £750.[5] In the United States this amount costs about 4,200 USD as of 2021.[6] It is made from antibodies from sheep that have been immunized with a digoxin derivative.[1][7]

Medical uses

It is used for digoxin toxicity when one of the following is present:[8][9]

  1. Hemodynamically unstable arrhythmia
  2. End organ damage
  3. digoxin level > 4 ng/ml if chronic ingestion
  4. digoxin level > 10 ng/ml if acute ingestion
  5. potassium > 5 mEq/L and symptomatic

Dosage

The dose depends on how much digoxin needs to be removed and the brand of medication.[1] A vial of DigiFab (40 mg) will remove about 0.5 mg of digoxin.[1] In acute toxicity the number of vials needed typically varies from 5 to 20 in adults; though more may be required.[1][10]

Contraindications

Avoid use in hypokalemia as this drug, while reversing the effects of digitalis, will further reduce serum potassium levels and could precipitate dangerous and even fatal cardiac arrhythmias.

The patient must be closely monitored for anaphylactic shock, and anyone allergic to sheep protein, papain, bromelain, or papaya extracts (papain is used to cleave the antibody into Fab and Fc fragments) should not use ovine digoxin immune fab. Because it is relatively new, no drug interaction studies have been performed yet.

Pharmacology

It works by binding to the digoxin, rendering it unable to bind to its action sites on target cells. The complexes accumulate in the blood and are expelled by the kidney.

Society and culture

Cost

In the United Kingdom one 40 mg vial cost the NHS about £750 as of 2020.[5] In the United States this amount costs about 4,200 USD as of 2021.[6]

Price increase were reported from US $380 to US $750 during 2013 in the United States. However, these price increases are not reflective of the United States average AWP for digoxin-Fab as it represents Australian costs converted to US. Prior to 2011, Digibind and DigiFab pricing was US $797 per 38 mg vial and US $786 per 40 mg vial respectively. After GSK discontinued Digibind sale in USA in 2011, the AWP of DigiFab increases by 15% to US $903 per 40 mg vial. AWP of DigiFab has continued to increase as much as 54% occurring in March 2014 to US $2,370 per 40 mg vial. However, the cost may vary depending on wholesaler contractor manufacturer rebates.

Intellectual property

Digifab is manufactured and distributed by BTG international Inc. under U.S. License No. 186. DigiFab is a sterile, lyophilized preparation of digoxin-immune ovine Fab (monovalent) immunoglobulin fragments. It is prepared by isolating the immunoglobulin fraction of the ovine serum, digesting it with papain and isolating the digoxin-specific Fab fragments by affinity chromatography. These antibody fragments have a molecular weight of approximately 46,000 Da. Each vial of DigiFab, which will bind approximately 0.5 mg digoxin, contains 40 mg of digoxin immune Fab, 75 mg (approx) of mannitol USP, and 2 mg (approx) sodium acetate USP as a buffering agent. The product contains no preservatives and is intended for intravenous administration.

Digibind is manufactured by GlaxoSmithkline, SpA, Parma Italy under US License No. 129. It’s distributed by GSK, Research Triangle park, NC 27709.

References

  1. 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 "Digoxin Immune Fab Monograph for Professionals". Drugs.com. Retrieved 22 July 2021.
  2. 2.0 2.1 "digoxin immune Fab (ovine)". www.glowm.com. Retrieved 8 September 2020.
  3. Briggs, Gerald G.; Freeman, Roger K.; Yaffe, Sumner J. (2008). Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk. Lippincott Williams & Wilkins. p. 542. ISBN 978-0-7817-7876-3.
  4. Shagufta, Dr Chandrawati Jee; Jee, Chandrawati (2008). Textbook Of Biotechnology. APH Publishing. p. 117. ISBN 978-81-313-0367-2.
  5. 5.0 5.1 BNF (80 ed.). BMJ Group and the Pharmaceutical Press. September 2020 – March 2021. p. 1440. ISBN 978-0-85711-369-6.CS1 maint: date format (link)
  6. 6.0 6.1 "DigiFab Prices, Coupons & Patient Assistance Programs". Drugs.com. Retrieved 22 July 2021.
  7. Sealock, Kara; Seneviratne, Cydnee; Lilley, Linda Lane; Collins, Shelly Rainforth; Snyder, Julie S. (18 October 2020). Lilley's Pharmacology for Canadian Health Care Practice - E-Book. Elsevier Health Sciences. p. 417. ISBN 978-0-323-69481-0.
  8. "Digoxin Toxicity". LITFL • Life in the Fast Lane Medical Blog. Retrieved 24 July 2017.
  9. "Digibind, DigiFab (digoxin immune FAB (Antidote)) dosing, indications, interactions, adverse effects, and more". reference.medscape.com. Retrieved 24 July 2017.
  10. Nickson, Chris (11 January 2019). "Digibind Antidote". Life in the Fast Lane • LITFL. Retrieved 22 July 2021.

External links

Identifiers: