Use of Dexmedetomidine in a Patient Allergic to Clonidine Presenting for an Awake Craniotomy: a Case Report

The use of dexmedetomidine with concurrent scalp block is increasingly being utilized as an effective and safe anesthetic approach for awake craniotomy (AC). Dexmedetomidine is an alpha-2 adrenergic receptor (α2-AR) agonist with dose-dependent sedative, analgesic, and anxiolytic properties while preserving respiratory function. The challenge with the use of dexmedetomidine arises when the patient has a clonidine allergy, which is also an α2-AR agonist. Currently, there is no published literature regarding the use of dexmedetomidine in a patient allergic to clonidine. A 48-year-old male with chronic obstructive pulmonary disease, obstructive sleep apnea, and body mass index of 54 with clonidine allergy presents for an AC. Given the goals of the surgery and the patient’s comorbidities, we planned for monitored anesthesia care with intravenous (IV) dexmedetomidine, remifentanil, and propofol. We discussed the use of dexmedetomidine with the patient and the potential risk of allergic reaction given his allergy to clonidine. The patient understood the risk and consented to the anesthetic plan. AC was successfully performed with IV dexmedetomidine, remifentanil, and propofol. Although both dexmedetomidine and clonidine have some functional similarities in terms of acting on the central and peripheral nervous system, there are marked differences between the two based on chemical structure, receptor affinity, and metabolism of the drug. This case highlights the successful use of dexmedetomidine in a patient with known allergy of rash to clonidine.