Iatrogenic Cushing's syndrome in HIV-infected patients receiving ritonavir and inhaled fluticasone: description of 4 new cases and review of the literature

Preventing Cushing: Iatrogenic Cushing Syndrome due to Ritonavir-Fluticasone Interaction

Ritonavir is commonly used in low doses to boost plasma levels of protease inhibitors in patients with human immunodeficiency virus (HIV) infections. It is also a potent inhibitor of cytochrome P450. We present a 50-year-old African American male with past medical history of HIV on highly active antiretroviral therapy (HAART), which also included ritonavir and long standing asthma that has been treated with inhaled fluticasone, who presented with back pain. He had central obesity, prominent abdominal striae and wasted extremities on physical examination. Laboratory tests showed low morning serum cortisol and suboptimal cosyntropin test consistent with adrenal insufficiency. Computed tomography (CT) of the spine showed a fracture of inferior endplate of the lumbar (L3) vertebra. The cause of osteoporosis is believed to be iatrogenic Cushing syndrome caused by enhanced levels of inhaled fluticasone effects secondary to inhibition of cytochrome P450. The patient was managed surgically and fluticasone was discontinued.

Iatrogenic Cushing's syndrome and osteoporosis due to an interaction between fluticasone and ritonavir

The advent of highly active antiretroviral therapy for HIV infection dramatically changed the landscape of the disease. Ritonavir, a protease inhibitor (PI) frequently used in low doses to 'boost' the concentrations of other PIs, inhibits the cytochrome P450 3A4 isoenzyme, a common metabolic pathway to multiple drugs, so the potential for drug interactions is not negligible. A 39-year-old man with HIV-1 infection, treated with a ritonavir-boosted PI, was started on fluticasone/salmeterol inhaler and intranasal fluticasone, in 2009, in the setting of asthma and allergic rhinitis. In 2013, he presented with 1-year evolution of symptoms suggesting Cushing's syndrome, and was experiencing recurrent falls. A spine CT showed a vertical L3 fracture and thoracolumbar erosions; a bone density scan revealed severe osteoporosis. Hormonal assays were compatible with hypothalamic-pituitary-adrenal axis suppression, and iatrogenic Cushing's syndrome due to ritonavir-fluticasone interaction was considered. Fluticasone was suspended and oral corticosteroid replacement initiated, with a favourable outcome.

Management of HIV/AIDS in older patients-drug/drug interactions and adherence to antiretroviral therapy

Patients with human immunodeficiency virus (HIV) are living longer with their disease, as HIV has become a chronic illness managed with combination antiretroviral therapy (cART). This has led to an increasing number of patients greater than 50 years old living successfully with HIV. As the number of older adults with HIV has increased, there are special considerations for the management of HIV. Older adults with HIV must be monitored for drug side effects and toxicities. Their other non-HIV comorbidities should also be considered when choosing a cART regimen. Older adults with HIV have unique issues related to medication compliance. They are more likely than the younger HIV patients to have vision loss, cognitive impairment, and polypharmacy. They may have lower expectations of their overall health status. Depression and financial concerns, especially if they are on a fixed income, may also contribute to noncompliance in the aging HIV population.

Iatrogenic Cushing syndrome and adrenal insufficiency during concomitant therapy with ritonavir and fluticasone

Ritonavir is a potent inhibitor of the cytochrome P450 enzyme CYP3A4 and is subject to multiple drug–drug interactions. This becomes especially important when the patient is also taking medications metabolized through CYP3A pathway as increased and potentially toxic drug levels may ensue. Herein we present one such interaction wherein a 57 year old gentleman with human immunodeficiency virus (HIV) infection on highly active antiretroviral therapy that included ritonavir, had addition of fluticasone inhaler to his medication repertoire for treatment of chronic obstructive pulmonary disease. This resulted in severe osteoporosis, iatrogenic Cushing syndrome and adrenal insufficiency due to the potentiated systemic glucocorticoid effect of inhaled fluticasone by ritonavir. This case emphasizes the need for pharmacovigilance when managing patients on complex drug regimens for physicians treating HIV infected patients.

Cushing's syndrome: from physiological principles to diagnosis and clinical care

The physiological control of cortisol synthesis in the adrenal cortex involves stimulation of adrenocorticotrophic hormone (ACTH) by hypothalamic corticotrophin-releasing hormone (CRH) and then stimulation of the adrenal by ACTH. The control loop of the hypothalamic-pituitary-adrenal (HPA) axis is closed by negative feedback of cortisol on the hypothalamus and pituitary. Understanding this system is required to master the diagnosis, differential diagnosis and treatment of endogenous hypercortisolism--Cushing's syndrome. Endogenous Cushing's syndrome is caused either by excess ACTH secretion or by autonomous cortisol release from the adrenal cortex. Diagnosis of cortisol excess exploits three physiological principles: failure to achieve the normal nadir in the cortisol diurnal rhythm, loss of sensitivity of ACTH-secreting tumours to cortisol negative feedback, and increased excretion of free cortisol in the urine. Differentiating a pituitary source of excess ACTH (Cushing's disease) from an ectopic source is accomplished by imaging the pituitary and sampling for ACTH in the venous drainage of the pituitary. With surgical removal of ACTH or cortisol-secreting tumours, secondary adrenal insufficiency ensues because of the prior suppression of the HPA axis by glucocorticoid negative feedback. Medical therapy is targeted to the anatomical location of the dysregulated component of the HPA axis. Future research will focus on new diagnostics and treatments of Cushing's syndrome. These are elegant examples of translational research: understanding basic physiology informs the development of new approaches to diagnosis and treatment. Appreciating pathophysiology generates new areas for inquiry of basic physiological and biochemical mechanisms.

Inhalational Steroids and Iatrogenic Cushing's Syndrome

Bronchial asthma (BA) and Allergic rhinitis (AR) are common clinical problems encountered in day to day practice, where inhalational corticosteroids (ICS) or intranasal steroids (INS) are the mainstay of treatment. Iatrogenic Cushing syndrome (CS) is a well known complication of systemic steroid administration. ICS /INS were earlier thought to be safe, but now more and more number of case reports of Iatrogenic Cushing syndrome have been reported, especially in those who are taking cytochrome P450 (CYP 450) inhibitors. Comparing to the classical clinical features of spontaneous Cushing syndrome, iatrogenic Cushing syndrome is more commonly associated with osteoporosis, increase in intra-ocular pressure, benign intracranial hypertension, aseptic necrosis of femoral head and pancreatitis, where as hypertension, hirsuitisum and menstrual irregularities are less common. Endocrine work up shows low serum cortisol level with evidence of HPA (hypothalamo-pituitary-adrenal) axis suppression. In all patients with features of Cushing syndrome with evidence of adrenal suppression always suspect iatrogenic CS. Since concomitant administration of cytochrome P450 inhibitors in patients on ICS/INS can precipitate iatrogenic CS, avoidance of CYP450 inhibitors, its dose reduction or substitution of ICS are the available options. Along with those, measures to prevent the precipitation of adrenal crisis has to be taken. An update on ICS-/INS- associated iatrogenic CS and its management is presented here.

Influence of low-dose ritonavir with and without darunavir on the pharmacokinetics and pharmacodynamics of inhaled beclomethasone

OBJECTIVE

To identify an alternative inhaled corticosteroid to fluticasone propionate that can be safely coadministered with HIV protease inhibitors, the safety and pharmacokinetics of beclomethasone dipropionate (BDP) and its active metabolite, beclomethasone 17-monopropionate (17-BMP), in combination with ritonavir (RTV) and darunavir/ritonavir (DRV/r) were assessed.

DESIGN

Open-label, prospective, randomized pharmacokinetic and pharmacodynamic study in healthy volunteers.

METHODS

Thirty healthy volunteers received inhaled 160 μg bid BDP for 14 days and were then randomized (1:1:1) into 3 groups: group 1 (control) remained on BDP alone for 28 days, group 2 received 100 mg bid BDP + RTV for 28 days, and group 3 received 600/100 mg bid BDP + DRV/r for 28 days. Pharmacokinetic sampling for 17-BMP was performed on days 14 and 28, and pharmacokinetic parameter values were compared within patients and between groups. Cortisol stimulation testing was also performed on days 1, 14, 28, and 42 and compared within and between groups.

RESULTS

Geometric mean ratios (day 28:day 14) (90% confidence interval) for 17-BMP area under the concentration-time curve in groups 1, 2, and 3, respectively, were 0.93 (0.81 to 1.06, P = 0.27), 2.08 (1.52 to 2.65, P = 0.006), and 0.89 (0.68 to 1.09, P = 0.61). There were no significant reductions in serum cortisol levels within or between groups (P > 0.05).

CONCLUSIONS

DRV/r did not increase 17-BMP exposure, whereas RTV alone produced a statistically significant but clinically inconsequential 2-fold increase in 17-BMP exposure. Adrenal suppression was not observed in any of the study groups. These data suggest that BDP can be safely coadministered with DRV/r and likely other RTV-boosted protease inhibitors.

Inhaled corticosteroid use in HIV-positive individuals taking protease inhibitors: a review of pharmacokinetics, case reports and clinical management

As a consequence of inhibition of the hepatic cytochrome P450 3A4 isozyme, treatment with HIV protease inhibitors can result in significant drug-drug interactions. One noteworthy interaction is between protease inhibitors and inhaled or intranasal corticosteroids. This interaction can result in adrenal insufficiency and iatrogenic Cushing's syndrome (with symptoms such as rapid weight gain, obesity, facial hirsutism and swelling), as well as hypertension, osteoporosis and decreased CD4 cell count. In this paper, we review and unite pharmacokinetic data, case reports and current research regarding this drug-drug interaction in order to suggest options for the clinical management of HIV-positive patients requiring treatment with protease inhibitors and inhaled or intranasal corticosteroids.

Important Drug-Drug Interactions in HIV-Infected Persons on Antiretroviral Therapy: An Update on New Interactions Between HIV and Non-HIV Drugs

Advances in antiretroviral therapy have turned HIV into a chronic, manageable disease. Patients often require treatment for co-morbid conditions as well as HIV, and consequently, pharmacokinetic interactions between antiretrovirals (ARVs) and other drug classes are an increasing concern. Protease inhibitors and non-nucleoside reverse transcriptase inhibitors are involved in the CYP450 or other transporter systems, and may be associated with higher risk of clinically significant drug interactions. One reverse transcriptase inhibitor, abacavir, has demonstrated weak inhibition of CYP3A4, 2D6 and 2C9 in vitro, but is not associated with any clinically significant interactions involving the CYP450 system. The integrase inhibitor raltegravir is not involved in the CYP450 system, and may be a suitable option to use when trying to minimize interactions with other drug classes. This review summarizes recently published data on clinically significant drug interactions between ARVs and other drug classes including antineoplastics, immunosuppressant transplant drugs, directly acting antivirals for hepatitis C, antifungals, antimalarials, corticosteroids, psychotropics, hormonal contraceptives, anticoagulants, drugs for pulmonary hypertension, and herbal products. In situations of suspected or potential interactions, close monitoring is warranted, and dose adjustments or substitutions may be required.

Ritonavir and epidural triamcinolone as a cause of iatrogenic Cushing's syndrome

Ritonavir is a protease inhibitor (PI) frequently prescribed with highly active antiretroviral therapy. It functions to boost the effectiveness of other PIs as a result of blocking their breakdown by the cytochrome P450 (3A4) pathway. Through this same mechanism, ritonavir has been shown to cause iatrogenic Cushing's syndrome (ICS) in patients using inhaled fluticasone. In addition, a small number of recent cases suggest that ritonavir may also cause this disorder by prolonging the duration of injected corticosteroids, such as triamcinolone. This case report presents a human immunodeficiency virus (HIV) patient taking ritonavir with ICS and secondary adrenal insufficiency, presumably due to systemic absorption and decreased metabolism of an epidural triamcinolone injection. To the authors knowledge, there have only been 4 previously reported cases describing ritonavir-potentiating ICS after receiving a corticosteroid epidural. This provides further proof that caution should be taken with nonparenteral use of triamcinolone in HIV patients on PIs.

Iatrogenic Cushing's syndrome following short-term intranasal steroid use

Cushing's syndrome (CS) is common after oral steroid use and has also been reported following topical or inhaled use, but it is extremely uncommon after intranasal administration. In this paper, we present the case of a child who developed CS after intranasal application of combined moxifloxacin-dexamethasone eye drops for epistaxis for a period of 3 months. CS caused by ocular preparations of steroids has not been reported previously. This case report highlights the fact that even eye drops can contain high doses of steroids and can lead to CS especially in children and especially if used intranasally. Ocular steroid drops should not be used intranasally. To minimize gastrointestinal absorption and therefore the risk of CS, nasal sprays should be preferred over nasal drops for intranasal steroid application.

Paying more than lip service to an oral lesion: a case of plasmablastic lymphoma

Plasmablastic lymphoma (PBL) is a variant of lymphoma originally described in the oral cavity of patients with advanced HIV. Our patient developed PBL despite well-controlled HIV and a CD4 count greater than 800 cells/µl. A drug interaction with an inhaled corticosteroid and ritonavir likely contributed to the development of this malignancy through increased immune suppression.

Inhaled fluticasone causes iatrogenic cushing's syndrome in patients treated with Ritonavir

INTRODUCTION

Ritonavir, a protease inhibitor (PI), is commonly used in the treatment of HIV-1 infection. It is a potent inhibitor of the hepatic cytochrome P450 superfamily. Therefore, its usage with other PI medications leads to significant increases in the levels of the latter PI, which allows a reduction in pill burden. Intranasal and inhaled corticosteroids are widely used for the treatment of allergic rhinitis and asthma. Inhaled steroids do not usually lead to systemic adverse events, since their plasma concentrations are quite low due to extensive first-pass metabolism and clearance by CYP3A4. However, the coadministration of Ritonavir with inhaled (or intranasal) corticosteroids may result in an increase in the plasma corticosteroid levels due to the potent CYP3A4 inhibition by Ritonavir. This may cause Cushing's syndrome (laboratory and clinical) with adrenal suppression.

METHODS

Plasma cortisol and urinary-free cortisol levels were determined using immunoassays. In the Synacthen test, plasma cortisol levels were measured at time 0 as well as at times 60, 120, and 150 minutes following an intramuscular injection of 0.25 mg Synacthen.

RESULTS

We present here three HIV-1 female patients aged 12, 55 and 65 years who developed iatrogenic Cushing's syndrome with adrenal suppression following the coadministration of Ritonavir and inhaled Fluticasone, both at the standard recommended doses.

CONCLUSIONS

The coadministration of Ritonavir and Fluticasone at the recommended doses caused, in our three patients, iatrogenic Cushing's syndrome with adrenal suppression. We suggest that this adverse event is underdiagnosed and high clinical suspicion is needed for early diagnosis and prenention of Addisonian crises. Thus, Fluticasone treatment should be avoided in patients who are treated with Ritonavir. Alternative therapeutic options for asthma control such as oral Montelukast or bronchodilators alone should be considered.

Predictors of clinically significant drug-drug interactions among patients treated with nonnucleoside reverse transcriptase inhibitor-, protease inhibitor-, and raltegravir-based antiretroviral regimens

BACKGROUND

The Department of Health and Human Services (DHHS) HIV treatment guidelines recommend that antiretroviral regimens for treatment-naïve individuals include at least 2 nucleoside reverse transcriptase inhibitors (NRTIs) plus either (1) a nonnucleoside reverse transcriptase inhibitor (NNRTI), (2) a protease inhibitor (PI), or (3) raltegravir, an integrase strand transfer inhibitor. Differences in drug-drug interaction potential may represent an important differentiating feature when choosing between these regimen types.

OBJECTIVE

To identify risk factors for clinically significant drug-drug interactions (CSDDIs) among patients on NNRTI-, PI-, and raltegravir-based antiretroviral regimens; compare CSDDI risks between these regimen types; and develop a clinical prediction tool for antiretroviral CSDDIs.

METHODS

In this cross-sectional study, outpatient medical records from the HIV clinic at Albany Medical Center Hospital were randomly selected to review patients' current antiretroviral regimens. Patients treated with NNRTI-, PI-, or raltegravir-based regimens were included. Drug therapies were analyzed for interactions using Lexi-Comp drug interaction software. The CSDDIs were defined as either (1) a drug combination that is contraindicated or accompanied by strong precautions per DHHS antiretroviral guidelines or (2) a drug combination that necessitates a medication dose adjustment.

RESULTS

Of the 500 patient records screened, 229 were included. Baseline characteristics were similar between regimen groups, with the exception of comorbidities. In multivariate analyses, variables independently associated with CSDDIs were use of >5 non-antiretroviral medications (prevalence ratio [PR] 1.86; 95% CI 1.31 to 2.64; p<0.001) and regimen type (NNRTI: PR 2.48, PI: PR 4.96, and raltegravir [referent]: PR 1.00; 95% CI 1.79 to 3.44; p<0.001).

CONCLUSIONS

Use of >5 non-antiretroviral medications or a non-raltegravir-based antiretroviral regimen increased the risk of a CSDDI. Our findings help clarify drug interaction risks among NNRTI-, PI-, and raltegravir-based regimen types that should be considered when prescribing antiretroviral therapy.

Exogenous Cushing's syndrome due to topical corticosteroid application: case report and review literature

Prolonged use of topical corticosteroids causes systemic adverse effects including Cushing's syndrome and hypothalamic-pituitary-adrenal (HPA) axis suppression, which is less common than that of the oral or parenteral route. At least 43 cases with iatrogenic Cushing syndrome from very potent topical steroid usage (Clobetasol) in children and adult have been published over the last 35 years particularly in developing countries. In children group (n = 22), most are infants with diaper dermatitis and two cases who had started topical application at a very early age and died from severe disseminated CMV infection. For the adult group (n = 21), the most common purpose of steroid use was for treatment of Psoriasis. The recovery period of HPA axis suppression was 3.49 ± 2.92 and 3.84 ± 2.51 months in children and adult, respectively. We report on an 8-month-old female infant who developed Cushing's syndrome and adrenal insufficiency after diaper dermatitis treatment through the misuse of Clobetasol without doctor's prescription. Physiologic dose of hydrocortisone was prescribed to prevent an adrenal crisis for 3 months and discontinued when HPA axis recovery was confirmed by normal morning cortisol and ACTH levels.

Iatrogenic Cushing's syndrome due to coadministration of ritonavir and inhaled budesonide in an asthmatic human immunodeficiency virus infected patient

INTRODUCTION

Iatrogenic Cushing's syndrome (CS) is caused by exposure to glucocorticoids and may be promoted by interaction with additional drugs. It is well known in asthmatic human immunodeficiency virus (HIV)-infected patients treated with inhaled fluticasone with ritonavir-containing antiretroviral regimen (cART).

CASE REPORT

The authors present an asthmatic HIV-infected Ethiopian woman, treated with fluticasone/salmeterol, commencing cART with tenofovir, emtricitabine, and lopinavir/ritonavir. During 7 months she gained 9 kg and hyperpigmentation, mild edema, marked abdominal striae, and increase in blood pressure were noted. Plasma am and urine free cortisol levels confirmed CS diagnosis and fluticasone was discontinued. Complete resolution of CS occurred within 2 months. However, frequent asthma symptoms required resumption of inhaled corticosteroid (ICS) treatment, and budesonide/formeterol was prescribed. Soon reemergence of symptomatic CS was noted. Ritonavir dose was halved, but CS symptoms continued to develop. Budesonide was stopped and montelukast initiated. Resolution of cushingoid symptoms was observed within weeks.

DISCUSSION

Corticosteroids are metabolized by cytochrome P450 3A4 (CYP3A4). Fluticasone has the longest glucocorticoid receptor-binding half-life and is 300 times more lipophilic than budesonide. Inhaled fluticasone possesses a high suppression rate of hypothalamic-pituitary-adrenal axis. Ritonavir, a potent CYP3A4 inhibitor, may inhibit corticosteroid degradation and increase its accumulation. Inhaled budesonide is less likely to cause adrenal suppression. Diagnosing Cushing's syndrome presents a clinical challenge due to similarities with clinical manifestations and side effects related to cART. In patients treated with inhaled or intranasal corticosteroids together with cART there may be a higher incidence of iatrogenic CS. CS should be looked for, and management considered carefully.

Cushing syndrome induced by parents: a report of two cases

Cushing syndrome developed in two children following inappropriate dosage and duration of corticosteroids by parents. One was a 7-year-old boy who was prescribed prednisolone for treatment of neurocysticercosis. The other was a 1-year-old boy who was prescribed oral betamethasone for a respiratory infection.

Cushing's syndrome of nonpituitary causes

PURPOSE OF REVIEW

Cushing's syndrome is being recognized with greater frequency and in patients with milder disease. Many of these individuals have nonpituitary causes of their hypercortisolism. This review discusses the classification, presentation, diagnosis, and therapy of patients with Cushing's syndrome from nonpituitary causes.

RECENT FINDINGS

Many previously unrecognized or poorly understood causes of Cushing's syndrome have been elucidated. It is now appreciated that essentially any form of exogenous glucocorticoid is capable of causing Cushing's syndrome. Additionally, new findings have led to a more complete understanding of bilateral nodular adrenal disease.

SUMMARY

The diagnosis of patients with less profound cortisol excess has increased the prevalence of Cushing's syndrome and made nonpituitary causes more common. As a result, clinicians must be cognizant of such patients and pursue the diagnosis when appropriate.