Endocrine Abstracts

A 40-year-old male presented with blackouts. This was associated with transient loss of consciousness with complete subsequent recovery. He did not have any warning signs, tongue biting or urinary incontinence. There was no history of alcohol or elicit drug abuse. He was admitted to MAU.

Past medical history: HIV diagnosed 18 months previously. Cutaneous and oral Kaposi’s sarcoma successfully treated with chemotherapy. Hepatitis C, asthma.

Drug history: (Tenofovir+Emtricitabine), (Lopinavir+Ritonavir), Valacyclovir, Seretide, Montelukast.

Examination: Rounded face. No postural BP drop. Proximal muscle weakness.

CVS/Respiratory/Abdominal/CNS examination unremarkable.

Investigations: FBC, U&Es, Bone, TFTs – Normal.

Random cortisol <30. ACTH <5. SST: Basal <30, 30 min 93

Adrenal cortex antibodies negative. CMV IgM −ve, IgG +ve.

Pituitary hormone profile – normal. (Testosterone – 5.7)

ECG-normal, CT head-NAD, CT abdomen – normal adrenals

Commenced on hydrocortisone 10, 5, 5 mg.

In subsequent clinic visits he did not complain of further episodes of collapses. He felt very tired and lethargic when attempted to taper the steroid dose.

Literature search shows individual case reports of interaction between Fluticasone and protease inhibitors. Normally, low plasma concentrations of fluticasone are achieved, due to high systemic clearance by cytochrome P450 3A4. However, ritonavir (a potent cytochrome P450 3A4 inhibitor) can increase fluticasone plasma concentrations, resulting in reduced serum cortisol concentrations. There have been reports of significant drug interactions in patients receiving fluticasone and ritonavir, resulting in systemic corticosteroid effects including Cushing’s syndrome and adrenal suppression. Other steroid preperations like Budesonide also have important interaction with cytochrome P450 3A4 and its use should be avoided with protease inhibitors like ritonavir. Prednisolone, Dexamethasone, Ciclesonide and Beclomethasone have minimal interaction with cytochrome P450 3A4 and can be safely used with protease inhibitors.

Our patient was switched from Fluticasone to Beclomethasone. He is still oral steroid dependant 4 months after presentation.