Clopidogrel Desensitization: Background and Recommendations for Use of a Rapid (4 Hour) Protocol

Curr Vasc Pharmacol. 2019;17(2):113-118. doi: 10.2174/1570161116666181031101930.

Abstract

The purpose of this section is to educate the reader on how to successfully manage patients with a hypersensitivity reaction to clopidogrel using desensitization protocol based on various published protocols. Additionally, we will define drug desensitization, and describe the possible mechanism of how desensitization may function as alternative medication. The indications/contraindications for desensitization will be reviewed. The different published clopidogrel desensitization protocols will be discussed. Based on those protocols, we recommend a protocol we feel is safe and efficacious. Clopidogrel is a thienopyridine antiplatelet drug widely used for treatment and also employed for secondary prevention regarding a range of cardiovascular diseases. However, it has been reported to cause hypersensitivity reactions. Ticlopidine is an alternative medication that can be considered when patients have an allergic reaction to clopidogrel. Additionally, ticlopidine is associated with increased risk causing potentially life-threatening adverse reactions to include: Aplastic anemia, reversible neutropenia, and thrombotic thrombocytopenia purpura vs. clopidogrel. Thus, clopidogrel desensitization offers an attractive alternative. Drug desensitization is defined as causing a temporary state of tolerance to a specific medication responsible for a hypersensitivity reaction. Furthermore, drug desensitization can only be maintained by continuous administration of this drug. Discussion: The exact immunologically mediated mechanism of how rapid oral desensitization works is not fully understood and yet to be defined. Ultimately desensitization results in causing antigen-specific mast cell tolerance. Various protocols have been published. The length of desensitization ranged from 2 h using 9 doses to 7 h using 15 doses. Recommendations: Taking the above into account, we recommend using a modification to the protocol that has the largest number of patients to undergo a standardized clopidogrel desensitization. This approach is shorter, as time has immense importance for these patients. Dosing starts at 10 mg dose and with 60 min intervals between doses, this now becomes a 4 h desensitization protocol.

Keywords: Rapid (4 Hour) protocol; allergy; alternative medication; clopidogrel desensitization; drug desensitization; hypersensitivity reaction..

Publication types

  • Review

MeSH terms

  • Cardiovascular Diseases / blood
  • Cardiovascular Diseases / diagnosis
  • Cardiovascular Diseases / drug therapy*
  • Clopidogrel / administration & dosage*
  • Clopidogrel / adverse effects
  • Desensitization, Immunologic*
  • Drug Administration Schedule
  • Drug Hypersensitivity / diagnosis
  • Drug Hypersensitivity / immunology
  • Drug Hypersensitivity / therapy*
  • Humans
  • Platelet Aggregation / drug effects
  • Platelet Aggregation Inhibitors / administration & dosage*
  • Platelet Aggregation Inhibitors / adverse effects
  • Purinergic P2Y Receptor Antagonists / administration & dosage*
  • Purinergic P2Y Receptor Antagonists / adverse effects
  • Risk Factors
  • Time Factors
  • Treatment Outcome

Substances

  • Platelet Aggregation Inhibitors
  • Purinergic P2Y Receptor Antagonists
  • Clopidogrel