Anaphylactoid reactions to vitamin K

Area of Science:

• Pharmacovigilance
• Clinical Pharmacology
• Adverse Drug Reactions

Background:

• Anaphylactoid reactions have been reported with intravenous vitamin K administration.
• Existing data on these reactions are scattered across published literature and adverse event databases.
• Understanding the incidence and characteristics of these reactions is crucial for patient safety.

Purpose of the Study:

• To comprehensively review and summarize reported anaphylactoid reactions associated with vitamin K administration.
• To analyze data from both published literature and unpublished reports to assess the scope of the problem.
• To inform clinical practice regarding the appropriate use of vitamin K.

Main Methods:

• Conducted literature searches using MEDLINE and EMBASE for published reports (1966-1999).
• Utilized the US Food and Drug Administration's Spontaneous Reporting System database for unpublished reports (1968-1997).
• Categorized adverse drug reactions by route, dose, and reaction type, defining anaphylactoid reactions based on specific clinical codes and reviewing fatal/life-threatening events.

Main Results:

• Identified 23 cases (3 fatal) of anaphylactoid reactions from published literature on intravenous vitamin K.
• The FDA database revealed 132 of 192 patients (69%) experiencing anaphylactoid reactions from intravenous vitamin K, with 24 fatalities (18%).
• Anaphylactoid reactions and fatalities were observed even with low doses (<5 mg) of intravenous vitamin K and in non-intravenous administration, though less frequently.

Conclusions:

• Anaphylactoid reactions to intravenous vitamin K, while rare overall, can be severe and fatal.
• The exact risk cannot be determined, but cases occur even with slow, dilute infusions.
• Intravenous vitamin K use should be restricted to patients with serious hemorrhage due to vitamin K deficiency-related coagulopathy.