Dermal Exposure to a Compounded Pain Cream Resulting in Severely Elevated Clonidine Concentration

• Published in: Journal of medical toxicology Vol. 10; no. 1; pp. 61 - 64
• Main Authors: Pomerleau, Adam C., Gooden, Casey E., Fantz, Corinne R., Morgan, Brent W.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01-03-2014; Springer Nature B.V
• Subjects: a1-Adrenergic receptors; Administration, Cutaneous; Adrenergic alpha-2 Receptor Agonists - administration & dosage; Adrenergic alpha-2 Receptor Agonists - poisoning; Adult; Analgesics - administration & dosage; Analgesics - blood; Analgesics - pharmacokinetics; Analgesics - poisoning; Biomedical and Life Sciences; Biomedicine; Bradycardia; Bradycardia - etiology; Bradycardia - prevention & control; Clonidine; Clonidine - administration & dosage; Clonidine - blood; Clonidine - pharmacokinetics; Clonidine - poisoning; Drug Combinations; Drug Compounding; Drug delivery systems; Drug overdose; Drug Overdose - blood; Drug Overdose - physiopathology; Drug Overdose - therapy; Emergency medical services; Exposure; Gabapentin; Hemorrhage; Humans; Hypertension; Hypertension - etiology; Hypertension - prevention & control; Imidazoline; Imipramine; Ketamine; Lidocaine; Male; Medication Adherence; Mefenamic acid; Neuropathy; Neurotoxicity Syndromes - etiology; Neurotoxicity Syndromes - prevention & control; Overdose; Pain; Pain management; Pharmacology/Toxicology; Skin; Skin Cream - adverse effects; Subarachnoid hemorrhage; Subarachnoid Hemorrhage - etiology; Subarachnoid Hemorrhage - prevention & control; Sympathomimetics; Toxicity; Toxicology Observation; Treatment Outcome; Young Adult; Adrenergic alpha 2 receptor agonists; Toxicology; Topical; Imidazoline receptors; Drug administration
• ISSN: 1556-9039; 1937-6995
• DOI: 10.1007/s13181-013-0331-x

Introduction
Clonidine is an imidazoline derivative antihypertensive medication that is also used as adjunctive therapy for neuropathic pain disorders via topical administration. Clonidine overdose can manifest both central and peripheral alpha-adrenergic agonist effects.
Case Report
A 23-year-old man presented to an emergency department with altered mental status, bradycardia, and hypertension after suspected overdose. He had rubbed a specially compounded medicinal cream over his entire body containing clonidine 0.2 % (
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), gabapentin 6 %, imipramine 3 %, ketamine 10 %, lidocaine 2 %, and mefenamic acid 1 %. The patient presented with severe hypertension, bradycardia, and altered mental status. He was found to have a subarachnoid hemorrhage and was treated for hypertensive emergency. Toxicological analysis of initial blood samples revealed a serum clonidine concentration of 5,200 ng/ml. At 6-month follow-up, the patient had made a full recovery.
Discussion
There are limited reports of topical clonidine toxicity, and to our knowledge, this case involves the highest concentration yet reported following clonidine overdose by any route of exposure. The severely elevated serum clonidine concentration found in our patient demonstrates the possibility of toxicity resulting from inappropriate use of such a product. At high serum concentrations, the pharmacodynamic effects of clonidine appear to cause significant peripheral alpha-1 adrenergic stimulation. Toxicologists should be aware of the increasing use of topical clonidine preparations for the treatment of neuropathic pain and the potential for toxicity.