Abstract
Purpose :
More than 38 million people in the world are infected with HIV (human immunodeficiency virus). Effective medications have drastically reduced the mortality yet carry significant side effects on metabolism. As more people are living with HIV, we report a patient who developed iatrogenic tertiary Cushing’s syndrome induced by subtenon triamcinolone in the setting of using Ritonavir and Darunavir, two protease inhibitors used to treat HIV.
Methods :
We report a patient with a severe side effect of subtenon triamcinolone (STK). The patient initially presented with blurred vision and was diagnosed with cystoid macular edema and subsequently failed topical NSAID therapy. He subsequently received 3 doses of 40mg STK in both eyes over the course of 8 months.
Results :
Within two months of starting STK, the patient started having progressively worsening exercise tolerance, dyspnea on exertion, lower extremity weakness, increased fat in face and abdomen, easy bruising, muscle wasting, and confusion. About a month after the third dose of STK, the patient was seen in the emergency department and admitted for further evaluation. ACTH level was 3.2pg/mL (normal 7-63pg/mL) and cortisol level was 2.0mcg/dL (normal 3.7-19.4mcg/dL). MRI of the pituitary gland of CT abdomen and adrenals were unremarkable. Cosyntropin stimulation test was normal. The patient had subsequent improvement with discontinuation of STK therapy and initiation of glucocorticoid replacement therapy for adrenal insufficiency. We believe this is related to inhibition of Cytochrome P450 3A4 (CYP3A4), which is the most abundant cytochrome P450 and is responsible for glucocorticoid metabolism. As part of treatment for HIV, the patient was taking Ritonavir and Darunavir, both of which cause strong inhibition of CYP3A4, which is responsible for glucocorticoid metabolism. Other HIV medications have similar inhibitory effects. Additionally, he was taking Amiodarone, which further inhibits CYP3A4.
Conclusions :
This case demonstrates the potential for severe complications of systemic drug interactions with periocular injections of corticosteroids and the importance of being aware of CYP3A4 inhibition of many HIV medications.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.