Iatrogenic Cushing Syndrome Following Lumbar Medial Branch Block in a Patient with HIV on Ritonavir and Darunavir

Abstract

We present a case report of a 62-year old female with HIV and chronic facetogenic back pain who underwent bilateral L3–L4 and L4–L5 medial branch nerve blocks using triamcinolone acetonide 80 mg. 2 weeks later she presented to the emergency department with acute anxiety/depression and was discharged with psychiatric follow-up. 2 weeks after this she presented to the outpatient HIV clinic with persistent uncontrolled depression alongside classic cushingoid features (e.g., buffalo hump, moon facies). She was diagnosed with iatrogenic Cushing syndrome caused by a drug–drug interaction between triamcinolone and ritonavir, a protease inhibitor and a CYP3A4 enzyme inhibitor. While the literature describes the interaction of ritonavir with intra-articular/intranasal/epidural triamcinolone, this is the first documented occurrence following a nerve block procedure. Symptoms resolved within 6 months alongside discontinuation of protease inhibitor therapy.

Lay abstract

We report a 62-year old woman with history of HIV and depression who developed Cushing syndrome, which is a state of steroid excess in the body, after a nerve block procedure for treatment of back pain. Her first symptoms were worsening anxiety and depression, causing her to go to the emergency department. Unfortunately, the relationship to the steroids was not identified at the time. Later, she developed increased fat deposition in her face and upper neck, which is characteristic of Cushing syndrome. The HIV medications responsible for this adverse event were determined to be ritonavir and darunavir, which are classified as protease inhibitors. Her symptoms improved within 6 months in association with discontinuation of ritonavir and darunavir. This is the first known case of Cushing syndrome following a nerve block procedure for back pain, although previous cases have documented this occurrence following other forms of steroid treatments.

Keywords::

• corticosteroids
• cushing syndrome
• HIV
• pain management
• triamcinolone

Author contributions

All authors listed on this title page have read the manuscript, attest to the validity and legitimacy of the information, and agree to its submission for publication inPain Management.

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.

Ethical conduct of research

The authors state that they have obtained appropriate institutional review board approval or have followed the principles outlined in the Declaration of Helsinki for all human or animal experimental investigations. In addition, for investigations involving human subjects, informed consent has been obtained from the participants involved.

Informed consent disclosure

The authors state that they have obtained verbal and written informed consent from the patient for the inclusion of their medical and treatment history within this case report. The purpose of this manuscript was explained, and the patient was assured that all identifying information will be removed.