Case report of severe bradycardia due to transdermal fentanyl

Background: This case report describes a patient who developed severe bradycardia due to transdermal fentanyl. There have been no prior case reports of this occurring in palliative care, but the frequency of association of fentanyl with bradycardia in the anesthesia setting suggests it may be more common than realized. Palliative care settings often have a policy of not routinely checking vital signs, and symptoms of bradycardia could be misinterpreted as the dying process. Case presentation: A patient with recurrent ovarian cancer was admitted with nausea and abdominal pain due to bowel obstruction and fever from a urinary tract infection. A switch from injectable hydromorphone to transdermal fentanyl resulted in symptomatic severe bradycardia within 36 h, without any other signs of opioid toxicity and with good analgesic effect. Case management: The fentanyl patch was removed. Atropine was not required. Case outcome: The patient made an uneventful recovery. Transdermal buprenorphine was subsequently used satisfactorily for long-term background pain control, with additional hydromorphone when needed. Conclusions: The delayed absorption of fentanyl via the transdermal route makes early identification of fentanyl-induced bradycardia key to prompt reversal. Patients with resting or relative bradycardia may be at higher than average risk.