Rifampicin-induced adrenal crisis in addisonian patients receiving corticosteroid replacement therapy

Disseminated tuberculosis in PLWHIV presenting as primary adrenal insufficiency

A woman in her 40s presented with a history of fatigue, symptoms of light-headedness on getting up from a sitting position and hyperpigmentation of the skin and mucous membranes. During the evaluation, she was diagnosed with primary adrenal insufficiency. Radiological imaging and microbiological evidence revealed features of disseminated tuberculosis involving the lungs and the adrenals. She was found to have an HIV infection. This patient was prescribed glucocorticoid and mineralocorticoid replacement therapy and was administered antituberculous and antiretroviral treatment.

The clinical presentation and treatment outcomes of ocular tuberculosis: a 5-year experience in an endemic area

PURPOSE

To report the clinical presentations of ocular tuberculosis infection (OTB) and the treatment regimen and outcome in an endemic area.

METHODS

This is a retrospective case series of patients with presumed OTB treated in a tertiary teaching hospital in Hong Kong in 2014-2019.

RESULTS

Among the nineteen patients recruited, the most common clinical presentation of OTB was retinal vasculitis (42.1%), followed by scleritis, intermediate uveitis, and choroidal tuberculoma (15.8% respectively). 94.7% and 94.4% of the subjects were treated with ATT and steroid, respectively, and 31.6% were put on systemic immunosuppressant prior to the initiation of ATT. Apart from those suffering from intermediate uveitis, most demonstrated good clinical response within 8 weeks of ATT initiation.

CONCLUSION

Ocular involvement of TB has been increasingly recognized, especially in endemic regions like Hong Kong. High index of suspicion is recommended for OTB in typical clinical phenotypes or recurrent/resistant ocular inflammation unresponsive to conventional therapy. TB retinal vasculitis was the most common presentation of OTB in this study and OTB generally requires treatment with either regional or systemic steroid together with ATT.

Drug Interactions between Antimicrobial and Immunosuppressive Agents in Solid Organ Transplant Recipients

The number of allogeneic solid organ and bone marrow transplants is increasing all over the world. To prevent transplant rejection and treat acute rejection of transplant, immunosuppressant drugs are used. The outcomes of solid organ transplants have dramatically improved over last 30 years, due to availability of multiple immunosuppressive agents, with varied mechanisms of action. The use of intense immunosuppression makes the individual having undergone solid organ transplant at the risk of several serious infections, which may prove fatal. To prevent and treat these infections (when they occur), patients are often given antimicrobial prophylaxis and therapy. The use of antimicrobials can interfere with the metabolism of the immunosuppressants, and may put the patient at risk of developing severe adverse effects due to unwanted increase or decrease in the serum levels of immunosuppressive agents. Knowledge of these interactions is essential for successful management of solid organ transplant patients. We therefore decided to review the literature and present the interactions that commonly occur between these two life-saving groups of drugs.

How to cite this article: Bhagat V, Pandit RA, Ambapurkar S, Sengar M, Kulkarni AP. Drug Interactions between Antimicrobial and Immunosuppressive Agents in Solid Organ Transplant Recipients. Indian J Crit Care Med 2021;25(1):67–76.

Abnormal Dexamethasone Suppression Tests in a Rifapentine-Treated Patient With Primary Aldosteronism

Aldosterone-producing adenoma (APA) is a main cause of primary aldosteronism (PA). Given that a large benign-appearing unilateral masse (>1 cm in diameter) may represent an aldosterone and cortisol-co-secreting adenoma, dexamethasone suppression testing is required in such patients to exclude or confirm the diagnosis of hypercortisolism. Tuberculosis is highly prevalent in China, and rifamycins are often used in these patients. Rifapentine belongs to the rifamycin family, and we herein for the first time report a case of misdiagnosis of hypercortisolism due to rifapentine use in a patient with APA. Thus, in patients treated with rifapentine, diagnosis of hypercortisolism based on dexamethasone suppression tests can be very misleading.

Adrenal insufficiency, be aware of drug interactions!

SUMMARY

A 42-year-old man with complaints of muscle soreness and an increased pigmentation of the skin was referred because of a suspicion of adrenal insufficiency. His adrenocorticotropic hormone and cortisol levels indicated a primary adrenal insufficiency (PAI) and treatment with hydrocortisone and fludrocortisone was initiated. An etiological workup, including an assessment for anti-adrenal antibodies, very long-chain fatty acids, 17-OH progesterone levels and catecholamine secretion, showed no abnormalities. 18Fluorodeoxyglucose positron emission tomography/CT showed bilateral enlargement of the adrenal glands and bilateral presence of an adrenal nodule, with 18fluorodeoxyglucose accumulation. A positive tuberculin test and positive family history of tuberculosis were found, and tuberculostatic drugs were initiated. During the treatment with the tuberculostatic drugs the patient again developed complaints of adrenal insufficiency, due to insufficient dosage of hydrocortisone because of increased metabolism of hydrocortisone.

LEARNING POINTS

Shrinkage of the adrenal nodules following tuberculostatic treatment supports adrenal tuberculosis being the common aetiology. The tuberculostatic drug rifampicin is a CYP3A4 inducer, increasing the metabolism of hydrocortisone. Increase the hydrocortisone dosage upon initiation of rifampicin in case of (adrenal) tuberculosis. A notification on the Addison's emergency pass could be considered to heighten physician's and patients awareness of hydrocortisone drug interactions.

Endocrinological aspects of HIV infection

PURPOSE

Patients with human immunodeficiency virus (HIV) are living longer with effective antiretroviral therapies and are enjoying near normal life span. Therefore, they are encountering endocrine issues faced by the general population along with those specific to HIV infection. The purpose of this article is to review the common endocrine aspects of HIV infection, and the early detection and management strategies for these complications.

METHODS

Recent literature on HIV and endocrine disease was reviewed.

RESULTS

HIV can influence endocrine glands at several levels. Endocrine glandular function may be altered by the direct effect of HIV viral proteins, through generation of systemic and local cytokines and the inflammatory response and via glandular involvement with opportunistic infections and HIV-related malignancies. Endocrine disorders seen in people with HIV include metabolic issues related to obesity such as diabetes, hyperlipidemia, lipohypertrophy, lipoatrophy and lipodystrophy and contribute significantly to quality of life, morbidity and mortality. In addition, hypogonadism, osteopenia and osteoporosis are also more prevalent in the patients with HIV. Although disorders of hypothalamic-pituitary-adrenal axis resulting in adrenal insufficiency can be life threatening, these along with thyroid dysfunction are being seen less commonly in the antiretroviral therapy (ART) era. ARTs have greatly improved life expectancy in people living with HIV but can also have adverse endocrine effects.

CONCLUSIONS

Clinicians need to have a high index of suspicion for endocrine abnormalities in people with HIV as they can be potentially life threatening if untreated. Endocrine evaluation should be pursued as in the general population, with focus on prevention, early detection and treatment to improve quality of life and longevity.

Immediate-release granule formulation of hydrocortisone, Alkindi®, for treatment of paediatric adrenal insufficiency (Infacort development programme)

Treatment of paediatric patients with adrenal insufficiency is challenging due to the lack of appropriate glucocorticoid preparations for children, and the use of either pharmacy- or parent-compounded hydrocortisone tablets. Alkindi (hydrocortisone granules in capsules for opening) is a new therapeutic option for paediatric adrenal insufficiency. Areas Covered: Drawbacks of current therapy and formulation and clinical trial programme for Alkindi. Expert Commentary: Compounding hydrocortisone has multiple issues including inconsistent dosing with under and over treatment and practical problems for parents who compound the drug themselves or travel long distances to a compounding pharmacy and the cost of compounding by the pharmacy. Alkindi® is a novel paediatric formulation of immediate release hydrocortisone licensed for use in paediatric adrenal insufficiency. Alkindi® is formulated to address the needs of neonates, infants and young children, being available at appropriate paediatric doses of 0.5, 1.0, 2.0 and 5.0 mg, is multiparticulate, allowing either direct oral dosing or dosing mixed with food, is taste masked to obscure the bitter taste of hydrocortisone and is bioequivalent to current hydrocortisone preparations. Clinical trials in young children with adrenal insufficiency demonstrated cortisol levels after dosing similar to those seen in healthy children and the drug was well tolerated and favoured over current therapy by parents. Alkindi® will provide a licenced treatment option for accurate dosing in children with adrenal insufficiency where compounded adult tablets of hydrocortisone are unsuitable.

Endocrine and Metabolic Aspects of Tuberculosis

Endocrine and metabolic derangements are infrequent in patients with tuberculosis, but they are important when they occur. The basis for these abnormalities is complex. While Mycobacterium tuberculosis has been described to infect virtually every endocrine gland, the incidence of gland involvement is low, especially in the era of effective antituberculosis therapy. Furthermore, endocrine and metabolic abnormalities do not always reflect direct infection of the gland but may result from physiological response or as a consequence of therapy. Metabolic disease may also predispose patients to the development of active tuberculosis, particularly in the case of diabetes mellitus. While hormonal therapy may be necessary in some instances, frequently these endocrine complications do not require specific interventions other than antituberculous therapy itself. With the exception of diabetes mellitus, which will be covered elsewhere, this chapter reviews the endocrinologic and metabolic issues related to tuberculosis.

CYP3A4 Induction by Rifampin: An Alternative Pathway for Vitamin D Inactivation in Patients With CYP24A1 Mutations

Context

The P450 enzyme CYP24A1 is the principal inactivator of vitamin D metabolites. Biallelic loss-of-function mutations in CYP24A1 are associated with elevated serum levels of 1,25-dihydroxyvitamin D3 with consequent hypercalcemia and hypercalciuria and represent the most common form of idiopathic infantile hypercalcemia (IIH). Current management strategies for this condition include a low-calcium diet, reduced dietary vitamin D intake, and limited sunlight exposure. CYP3A4 is a P450 enzyme that inactivates many drugs and xenobiotics and may represent an alternative pathway for inactivation of vitamin D metabolites.

Objective

Our goal was to determine if rifampin, a potent inducer of CYP3A4, can normalize mineral metabolism in patients with IIH due to mutations in CYP24A1.

Methods

We treated two patients with IIH with daily rifampin (10 mg/kg/d, up to a maximum of 600 mg). Serum calcium, phosphorus, parathyroid hormone (PTH), liver, and adrenal function and vitamin D metabolites, as well as urinary calcium excretion, were monitored during treatment of up to 13 months.

Results

Prior to treatment, both patients had hypercalcemia, hypercalciuria, and nephrocalcinosis with elevated serum 1,25-dihydroxyvitamin D3 and suppressed serum PTH. Daily treatment with rifampin was well tolerated and led to normalization or improvement in all clinical and biochemical parameters.

Conclusion

These observations suggest that rifampin-induced overexpression of CYP3A4 provides an alternative pathway for inactivation of vitamin D metabolites in patients who lack CYP24A1 function.

Clinical features and practice patterns of treatment for adrenal crisis: a nationwide cross-sectional study in Japan

CONTEXT

Adrenal crisis is an endocrine emergency that requires prompt diagnosis and treatment. However, the clinical features and practice patterns of treatment for adrenal crisis are not completely understood.

OBJECTIVE

To investigate patient characteristics, comorbidities and treatments of adrenal crisis.

METHODS

We conducted a cross-sectional study of patients who received intravenous glucocorticoids for adrenal crisis at admission from 1 July 2007 to 31 March 2014, using a national inpatient database in Japan.

RESULTS

Among approximately 34 million inpatients in the database, we identified 799 patients diagnosed with adrenal crisis and coexisting primary or secondary adrenal insufficiency at admission. The median (interquartile range) age was 58 (28-73) years, and the overall in-hospital mortality was 2.4% (19 of 799 patients). The most common comorbidity at admission was infections excluding pneumonia and gastroenteritis (15.0%). There were 68 (8.5%) patients with gastroenteritis, and no deaths occurred among these patients. The patients with secondary adrenal insufficiency showed significantly higher proportions of admission to ICU, extracellular fluid resuscitation, insulin therapy and catecholamine use than the patients with primary adrenal insufficiency. There were no significant between-group differences in mortality rate and variation in intravenous glucocorticoids (short-acting glucocorticoid, hydrocortisone; moderate-acting glucocorticoid, prednisolone or methylprednisolone; long-acting glucocorticoid, dexamethasone or betamethasone). Of the 19 dead patients, 15 were aged above 60 years, 12 had impaired consciousness at admission and 13 received insulin therapy.

CONCLUSIONS

Clinicians should be aware that older patients with impaired consciousness and diabetes mellitus are at relatively high risk of death from adrenal crisis.

Diagnosis and treatment of adrenal insufficiency including adrenal crisis: a Japan Endocrine Society clinical practice guideline [Opinion]

This clinical practice guideline of the diagnosis and treatment of adrenal insufficiency (AI) including adrenal crisis was produced on behalf of the Japan Endocrine Society. This evidence-based guideline was developed by a committee including all authors, and was reviewed by a subcommittee of the Japan Endocrine Society. The Japanese version has already been published, and the essential points have been summarized in this English language version. We recommend diagnostic tests, including measurement of basal cortisol and ACTH levels in combination with a rapid ACTH (250 μg corticotropin) test, the CRH test, and for particular situations the insulin tolerance test. Cut-off values in basal and peak cortisol levels after the rapid ACTH or CRH tests are proposed based on the assumption that a peak cortisol level ≥18 μg/dL in the insulin tolerance test indicates normal adrenal function. In adult AI patients, 15-25 mg hydrocortisone (HC) in 2-3 daily doses, depending on adrenal reserve and body weight, is a basic replacement regime for AI. In special situations such as sickness, operations, pregnancy and drug interactions, cautious HC dosing or the correct choice of glucocorticoids is necessary. From long-term treatment, optimal diurnal rhythm and concentration of serum cortisol are important for the prevention of cardiovascular disease and osteoporosis. In maintenance therapy during the growth period of patients with 21-hydroxylase deficiency, proper doses of HC should be used, and long-acting glucocorticoids should not be used. Education and carrying an emergency card are essential for the prevention and rapid treatment of adrenal crisis.

Hypothalamic-pituitary-adrenal axis in HIV infection and disease

HIV infection induces hypothalamic-pituitary-adrenal (HPA) axis derangements. Partial glucocorticoid resistance has been observed in a subset of AIDS patients, possibly owing to HIV-induced altered cytokine secretion and action. Because glucocorticoids have immunomodulatory effects, the severity of the HPA axis disorder could play a central role in disease progression. The characteristic phenotype of AIDS patients (visceral obesity, lipodystrophy) may be owing to effects of HIV proteins on the HPA axis, including changes in glucocorticoid and insulin sensitivity of target tissues, as well as altered cytokine production and interaction with the HPA axis, genetic causes, comorbidities, and, possibly, use of antiretroviral agents.

Antimicrobial and immunosuppressive drug interactions in solid organ transplant recipients

Infections are frequent and can be severe in recipients of solid organ transplantation. Prevention and treatment are priority objectives of multidisciplinary transplant teams. Interactions between antimicrobials (indicated for prevention and therapy) and immunosuppressants (for preventing rejection) make treatment more complex than in the general population. Co-administration of immunosuppressants and antibiotics can cause harmful interactions, modifying the pharmacokinetic and pharmacodynamic characteristics of both groups of drugs. The loss of the transplanted organ due to reduced levels of immunosuppressants is a unique consequence of the often lethal interactions in this group of patients. By contrast, elevated levels of these drugs cause toxicity, and reduced concentrations of antimicrobial treatment fail to contain the infection. Azoles, rifabutin, protease inhibitors, non-nucleoside reverse transcriptase inhibitors and antimicrobial macrolides all interact with immunosuppressants. In this article, we review interactions between antibiotics and immunosuppressants in order to adopt the most appropriate clinical approach (dosage adjustments, close monitoring of plasma levels and organ function) and determine whether they can be used together with any measure of safety.

What is the best long-term management strategy for patients with primary adrenal insufficiency?

Primary adrenal insufficiency is treated with glucocorticoid and mineralocorticoid replacement therapy. Recent data revealed that health-related quality of life in adrenal insufficiency is impaired in many patients and that patients with adrenal insufficiency are also threatened by an increased mortality and morbidity. This may be caused by inadequate glucocortiocid therapy and adrenal crisis. Therefore, the optimization of hormone replacement therapy remains one of the most challenging tasks in endocrinology because it is largely based on clinical grounds because of the lack of objective assessment tools. This article provides answers to the important daily clinical questions, such as correct dose finding, dose adaptation in special situations, e g, pregnancy, improvement of quality of life and measures for protection from adrenal crisis. Other important aspects discussed are side effects of glucocortiocid replacement therapy and interactions with other drugs.

Erythema induratum of Bazin associated with Addison's disease: first description

CONTEXT

Erythema induratum of Bazin (EIB) is considered to be a tuberculid reaction and consists of recurrent painful nodules. The differential diagnosis includes diseases like nodular vasculitis, perniosis, polyarteritis nodosa and erythema nodosum.

CASE REPORT

We report the case of a woman with EIB who developed Addison's disease during treatment with anti-tuberculosis drugs with good response to glucocorticoid replacement. The diagnosis was obtained through the clinical picture, positive tuberculin test and positive BCG (bacillus Calmette-Guérin) test on the histological sample. Anti-tuberculosis drugs and glucocorticoid replacement led to disappearance of the signs and symptoms.

CONCLUSIONS

This is the first description of an association between EIB and Addison's disease. It should be borne in mind that tuberculosis is an important etiological factor for Addison's disease.

Adverse effect of phenytoin on glucocorticoid replacement in a child with adrenal insufficiency

Chronic administration of antiepileptic agents such as phenytoin can increase clearance rates of cortisol and synthetic glucocorticoids through hepatic microsomal enzyme induction. However, data concerning an adverse interaction between antiepileptic and steroid drugs are scarce. We herein report an adolescent boy with primary adrenal insufficiency that developed glucocorticoid deficiency after added phenytoin treatment. The patient had an increased requirement for hydrocortisone replacement, and two episodes of vomiting, hyponatremia and mild hypoglycemia. His ACTH levels were markedly elevated. Fifteen days after stopping phenytoin, his serum ACTH concentration returned to normal range. Even though the hydrocortisone dose was gradually decreased, hyponatremia and vomiting have not recurred. In conclusion, we suggest that drugs such as phenytoin affecting hepatic clearance of synthetic glucocorticoids and mineralocorticoids should not be preferred for therapy in patients with adrenal insufficiency. If their use is vital, one should be aware of increased replacement requirements for steroid drugs, and patients should be closely monitored.

Drug-induced endocrine disorders in the intensive care unit

The neuroendocrine response to critical illness is key to the maintenance of homeostasis. Many of the drugs administered routinely in the intensive care unit significantly impact the neuroendocrine system. These agents can disrupt the hypothalamic-pituitary-adrenal axis, cause thyroid abnormalities, and result in dysglycemia. Herein, we review major drug-induced endocrine disorders and highlight some of the controversies that remain in this area. We also discuss some of the more rare drug-induced syndromes that have been described in the intensive care unit. Drugs that may result in an intensive care unit admission secondary to an endocrine-related adverse event are also included. Unfortunately, very few studies have systematically addressed drug-induced endocrine disorders in the critically ill. Timely identification and appropriate management of drug-induced endocrine adverse events may potentially improve outcomes in the critically ill. However, more research is needed to fully understand the impact of medications on endocrine function in the intensive care unit.

Pituitary tumours: inflammatory and granulomatous expansive lesions of the pituitary

Inflammatory and granulomatous diseases of the pituitary are rare causes of sellar masses. Lymphocytic hypophysitis is the most relevant of these disorders, and it is characterised by autoimmune pathogenesis with focal or diffuse inflammatory infiltration and varying degrees of pituitary gland destruction. Endocrine symptoms may include partial or total hypopituitarism, with adrenocorticotropic hormone (ACTH) deficiency being the earliest and most frequent alteration. Pituitary abscess is a rare but potentially life-threatening disease and, in 30-50% of patients, anterior pituitary hormone deficiencies or central diabetes insipidus (DI) at onset may be observed: the earliest manifestation being growth hormone deficiency (GHD), followed by follicle-stimulating hormone (FSH)/luteinising hormone (LH), thyroid-stimulating hormone (TSH) and ACTH deficiencies. Fungal infections of the pituitary are also very rare and include aspergillosis and coccidioidomycosis. Concerning pituitary involvement in systemic diseases, in sarcoidosis endocrine complications are rare, but the hypothalamus and pituitary are the glands most commonly affected. DI is reported in approximately 25-33 % of all neurosarcoidosis cases and is the most frequently observed endocrine disorder. Hyperprolactinaemia and anterior pituitary deficiencies may also occur. Rarely, partial or global anterior pituitary dysfunction may be present also in Wegener's granulomatosis, either at onset or in the course of the disease, resulting in deficiency of one or more of the pituitary axes. Other forms of granulomatous pituitary lesions include idiopathic giant cell granulomatous hypophysitis, Takayasu's disease, Cogan's syndrome and Crohn's disease. The hypotalamic-pituitary system is involved mainly in children with Langerhans' cells histiocytosis who develop DI, which is the most common endocrine manifestation. Anterior pituitary dysfunction is found more rarely and is almost invariably associated with DI. Pituitary involvement may also be observed in another form of systemic hystiocitosis, that is, Erdheim-Chester disease. Tuberculosis is a rare cause of hypophysitis, which may present with features of anterior pituitary dysfunction, such as hypopituitarism with hyperprolactinaemia. In conclusion, in patients with a sellar mass and unusual clinical presentation (DI, neurological symptoms), aggressiveness and onset and in the presence of systemic diseases, inflammatory and granulomatous pituitary lesions should be carefully considered in differential diagnosis.

Clinically Significant Drug–Drug Interactions Between Oral Anticancer Agents and Nonanticancer Agents: Profiling and Comparison of Two Drug Compendia

Background:

Use of oral anticancer agents is gaining wide acceptance in the treatment of cancer. However, patients receiving oral therapy are at high risk for drug–drug interactions (DDIs).

Objective:

To create a drug profile for each clinically significant DDI involving selected oral anticancer agents and evaluate the agreement between 2 commonly used DDI compendia: Drug Interaction Facts (DIF) 2008 and Micromedex DRUGDEX.

Methods:

DDI profiles were developed based on primary and tertiary literature reviews. DIF 2008 and Micromedex DRUGDEX were compared to assess the consistency of listings, severity, and scientific evidence ratings of DDIs involving the oral anticancer agents that were selected. The Spearman correlation test was used to assess the correlation of the severity ratings between the 2 compendia.

Results:

A total of 184 DDIs were identified. A DDI profile was created for 40 of these that met the predetermined criteria for clinically significant interactions. The comparative assessment showed inconsistency in DDI listings (15.2% of those identified were listed in DIF only and 46.7% were listed in Micromedex only), severity ratings (Spearman correlation coefficient 0.49), and scientific evidence ratings (disagreement 25.8%).

Conclusions:

The discrepancies in DDI listing and rating systems between the compendia evaluated here reflect the need for more studies to standardize the definitions and classifications of DDIs.

Glucocorticoid replacement therapy in patients with Addison's disease

One hundred and fifty years ago, Thomas Addison published his classic paper on the 'Constitutional and Local Effects of Disease of the Supra-renal Capsules', in which he described 11 patients with the disorder that would come to bear his name. Adrenal insufficiency is a rare disease, but its prevalence is increasing. The most frequent causes of adrenal insufficiency in western countries are autoimmune adrenalitis, but other causes include, tuberculosis systemic fungal infections, AIDS, metastatic carcinoma and isolated glucocorticoid deficiency. It is clear that autoimmunity precedes overt Addison's disease by years, as in many autoimmune endocrine disorders. Adrenocortical function is lost over a period of years as it progresses to overt Addison's disease. This editorial discusses the controversial glucocorticoid replacement therapy in patients with Addison's disease, and aims to provide a good review of literature and suggested guidelines for appropriate treatment of this disease.

Why is the management of glucocorticoid deficiency still controversial: a review of the literature

All endocrinologists would like to make glucocorticoid replacement therapy for their hypoadrenal patients as physiological as possible. Many would like the reassurance of a method of monitoring such treatment to confirm that they are achieving this aim. Advances in our knowledge of the normal physiology are relevant to our attempts to do this. The cortisol production rate in normal subjects is lower than was previously believed. The normal pattern of glucocorticoid secretion includes both a diurnal rhythm and a pulsatile ultradian rhythm. Glucocorticoid access to nuclear receptors is 'gated' by the 11-beta-hydroxysteroid dehydrogenase enzymes, which interconvert active cortisol and inactive cortisone. Such complexities make the target of physiological glucocorticoid replacement therapy hard to achieve. The available evidence suggests that conventional treatment of hypoadrenal patients may result in adverse effects on some surrogate markers of disease risk, such as a lower bone mineral density than age-sex matched controls, and increases in postprandial glucose and insulin concentrations. Although the quality of life of hypoadrenal patients may be impaired, there is no evidence of an improvement on higher doses of steroids, although quality of life is better if the hydrocortisone dose is split up, with the highest dose taken in the morning. Thus the evidence suggests that most patients may safely be treated with a low dose of glucocorticoid (e.g. 15 mg hydrocortisone daily) in two or three divided doses, with education about the appropriate action to take in the event of intercurrent illnesses.

Safety of low dose glucocorticoid treatment in rheumatoid arthritis: published evidence and prospective trial data

Adverse effects of glucocorticoids have been abundantly reported. Published reports on low dose glucocorticoid treatment show that few of the commonly held beliefs about their incidence, prevalence, and impact are supported by clear scientific evidence. Safety data from recent randomised controlled clinical trials of low dose glucocorticoid treatment in RA suggest that adverse effects associated with this drug are modest, and often not statistically different from those of placebo.

Steroid hormone biotransformation and xenobiotic induction of hepatic steroid metabolizing enzymes

Normal reproductive development depends on the interplay of steroid hormones with their receptors at specific tissue sites. The concentrations of hormone ligands in the circulation and at target sites are maintained through coordinated regulation on steroid biosynthesis and degradation. Changed bioavailability of steroids, through alteration of steroidogenesis or biotransformation rates, leads to changes in endocrine function. Steroid hormones lose their receptor reactivity in most cases when they are bound to binding proteins, while metabolic conversion can result in either active or inactive metabolites. Hydroxylation by cytochrome P450 (CYP) enzymes and conjugation with glucuronide and sulfate are among the major hepatic pathways of steroid inactivation. The expression of these biotransformation enzymes can be induced by many xenobiotics. The barbiturate phenobarbital and the environmental toxicant 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE) are among the well characterized inducers for the CYP 2B and 3A enzymes and selected conjugation enzymes. The induction of the steroid biotransformation enzymes is partly mediated through the activation of a group of nuclear receptors including the glucocorticoid receptor, the constitutive androstane receptor (CAR), the pregnane X receptor (PXR), and the peroxisome proliferator activated receptors (PPAR). Drug or chemical-induced increases in hepatic enzyme activities are often a basis for drug-drug interactions that lead to enhanced elimination and reduced therapeutic efficacy of steroidal drugs. The effects of enzyme induction on endogenous steroid clearance, along with its possible consequence, are less well understood. While enzyme induction by xenobiotics may increase clearance of the endogenous steroid, regulatory mechanisms for steroid homeostasis may adapt and compensate for altered clearance.

The endocrinology of adrenal tuberculosis: the effects of tuberculosis on the hypothalamo-pituitary-adrenal axis and adrenocortical function

Tuberculosis may affect many of the endocrine glands including the hypothalamus, pituitary, thyroid and adrenals. The most commonly involved endocrine organ in tuberculosis is the adrenal gland. Adrenal glands may be directly or indirectly affected by tuberculosis. Tuberculous Addison's disease is still an important cause of primary adrenocortical insufficiency particularly in the developing countries. Recent improvements in imaging techniques and modern endocrinological tests for the investigation of adrenal function have given us greater insight into the endocrinology of adrenal tuberculosis. Hypothalamo-pituitary-adrenal (HPA) axis is also involved in tuberculosis and recent findings revealed that HPA axis is activated rather than underactivated in active pulmonary tuberculosis. Activated HPA axis in tuberculosis causes increased cortisol secretion which results in a shift in the Th1/Th2 balance towards Th2. T cell dysfunction due to high cortisol and low DHEAS levels may be responsible for immunologically-mediated tissue damage in tuberculosis. In this review, recent findings concerning the adrenocortical function, radiological changes in adrenal glands and HPA axis involvement in tuberculosis are discussed.

Troglitazone induces CYP3A4 activity leading to falsely abnormal dexamethasone suppression test

After evaluating a patient who appeared to have a falsely abnormal response to the dexamethasone suppression test while taking troglitazone, we examined the effects of troglitazone on the activity of hepatic CYP3A4 and the screening tests for Cushing's syndrome. We studied five healthy women and three healthy men, aged 25 +/- 2 yr, before and after treatment with troglitazone (600 mg daily) for 28 d. Baseline 0800 h cortisol and corticosterone were similar before and after troglitazone treatment. Before troglitazone treatment, all subjects suppressed 0800 h cortisol below 1.8 micro g/dl (mean, 0.66 +/- 0.08 micro g/dl) during the 1-mg overnight dexamethasone suppression test (DST), whereas during troglitazone treatment none of the subjects suppressed 0800 h cortisol below 1.8 micro g/dl (mean, 9.0 +/- 1.8 micro g/dl). Serum dexamethasone levels decreased by 66 +/- 4%, and the erythromycin breath test measurements increased by 27 +/- 8%, indicating increased CYP3A4 activity during troglitazone treatment. The hydrocortisone suppression test (HST) was performed by administering 50 mg hydrocortisone at 2300 h. Using the criterion of suppression of 0800 h plasma corticosterone by more than 50%, the specificity of the HST was 100% both before and after troglitazone treatment. In conclusion, troglitazone induced the activity of CYP3A4 leading to falsely abnormal DST. HST is a useful alternative to the DST in patients taking medications that increase the activity of CYP3A4.

Clinically significant interactions with drugs used in the treatment of tuberculosis

Clinically significant interactions occurring during antituberculous chemotherapy principally involve rifampicin (rifampin), isoniazid and the fluoroquinolones. Such interactions between the antituberculous drugs and coadministered agents are definitely much more important than among antituberculous drugs themselves. These can be associated with consequences even amounting to therapeutic failure or toxicity. Most of the interactions are pharmacokinetic rather than pharmacodynamic in nature. The cytochrome P450 isoform enzymes are responsible for many interactions (especially those involving rifampicin and isoniazid) during drug biotransformation (metabolism) in the liver and/or intestine. Generally, rifampicin is an enzyme inducer and isoniazid acts as an inhibitor. The agents interacting significantly with rifampicin include anticoagulants, anticonvulsants, anti-infectives, cardiovascular therapeutics, contraceptives, glucocorticoids, immunosuppressants, psychotropics, sulphonylureas and theophyllines. Isoniazid interacts principally with anticonvulsants, theophylline, benzodiapines, paracetamol (acetaminophen) and some food. Fluoroquinolones can have absorption disturbance due to a variety of agents, especially the metal cations. Other important interactions of fluoroquinolones result from their enzyme inhibiting potential or pharmacodynamic mechanisms. Geriatric and immunocompromised patients are particularly at risk of drug interactions during treatment of their tuberculosis. Among the latter, patients who are HIV infected constitute the most important group. This is largely because of the advent of new antiretroviral agents such as the HIV protease inhibitors and the non-nucleoside reverse transcriptase inhibitors in the armamenterium of therapy. Compounding the complexity of drug interactions, underlying medical diseases per se may also contribute to or aggravate the scenario. It is imperative for clinicians to be on the alert when treating tuberculosis in patients with difficult co-morbidity requiring polypharmacy. With advancement of knowledge and expertise, it is hoped that therapeutic drug monitoring as a new paradigm of care can enable better management of these drug interactions.

Altered corticosteroid metabolism differentially affects pituitary corticotropin response

To evaluate the effects of altered corticosteroid metabolism on the hypothalamic-pituitary-adrenal axis, we examined rats treated with glycyrrhizic acid (G rats) or rifampicin (R rats) for 7 days. The half-life of exogenously administered hydrocortisone as a substitute for corticosterone was longer in G rats and shorter in R rats, with no differences in basal plasma levels of ACTH or corticosterone. The ACTH responses to human corticotropin-releasing factor (CRF) or insulin-induced hypoglycemia were greater in G rats and tended to be smaller in R rats compared with those in the control rats, whereas the corticosterone response was similar. No difference was observed in the content and mRNA level of hypothalamic CRF among the groups. The number and mRNA level of CRF receptor and type 1 11 beta-hydroxysteroid dehydrogenase (11-HSD1) mRNA level in the pituitary were increased in G rats but not changed in R rats, suggesting that chronically increased intrapituitary corticosterone upregulates pituitary CRF receptor expression. In contrast, CRF mRNA levels in the pituitary were increased in R rats. Our data indicate novel mechanisms of corticosteroid metabolic modulation and the involvement of pituitary 11-HSD1 and CRF in glucocorticoid feedback physiology.

Primary hypoadrenalism assessed by the 1 microg ACTH test in hospitalized patients with active pulmonary tuberculosis

Primary hypoadrenalism, assessed by 250 microg ACTH stimulation, is uncommon in patients with active pulmonary tuberculosis (PTB). Since 1 microg ACTH produces an equivalent +30 min cortisol response to 250 microg in control subjects, the 250 microg dose is supraphysiological and may lack sensitivity for the diagnosis of hypoadrenalism. Furthermore, the impact of coexistent HIV infection on the prevalence of primary hypoadrenalism in PTB is uncertain. We thus determined the cortisol response to an intravenous bolus of 1 microg ACTH in 21 controls, 18 HIV-positive (BMI 19.5+/-0.9 kg/m(2), albumin 24+/-1.4 g/l, CD4 count 192+/-47/mm(3)) and 22 HIV-negative (BMI 19.3+/-0.8 kg/m(2), albumin 29+/-1 g/l, CD4 count 652+/-76/mm(3)) patients with active PTB. The mean basal cortisol was greater in patients than in controls (559 vs. 373 nmol/l, p=0. 0009). The mean cortisol after 1 microg ACTH stimulation did not, however, differ significantly when comparing either patients and controls or patients who were HIV-positive and -negative (p>0.05). Using the minimum +30 min cortisol derived from the 21 controls as a marker of normal adrenal function (414 nmol/l), a single patient was classified as hypoadrenal. In conclusion, primary hypoadrenalism, as assessed by the 1 microg ACTH test, is uncommon in a cohort of ill, hospitalized patients with active PTB, irrespective of HIV status.

SXR, a novel steroid and xenobiotic-sensing nuclear receptor

An important requirement for physiologic homeostasis is the detoxification and removal of endogenous hormones and xenobiotic compounds with biological activity. Much of the detoxification is performed by cytochrome P-450 enzymes, many of which have broad substrate specificity and are inducible by hundreds of different compounds, including steroids. The ingestion of dietary steroids and lipids induces the same enzymes; therefore, they would appear to be integrated into a coordinated metabolic pathway. Instead of possessing hundreds of receptors, one for each inducing compound, we propose the existence of a few broad specificity, low-affinity sensing receptors that would monitor aggregate levels of inducers to trigger production of metabolizing enzymes. In support of this model, we have isolated a novel nuclear receptor, termed the steroid and xenobiotic receptor (SXR), which activates transcription in response to a diversity of natural and synthetic compounds. SXR forms a heterodimer with RXR that can bind to and induce transcription from response elements present in steroid-inducible cytochrome P-450 genes and is expressed in tissues in which these catabolic enzymes are expressed. These results strongly support the steroid sensor hypothesis and suggest that broad specificity sensing receptors may represent a novel branch of the nuclear receptor superfamily.

Mineralocorticoid insufficiency due to suramin therapy

BACKGROUND

During a Phase I trial of suramin, a novel antineoplastic agent with activity against hormone-refractory prostate carcinoma, the authors observed two patients with clinical mineralocorticoid insufficiency in spite of hydrocortisone replacement therapy.

METHODS

The authors retrospectively assessed adrenal cortical function in 20 such patients via adrenocorticotropic stimulation testing, measuring both cortisol and aldosterone responses, either at the time or treatment of immediately after discontinuation of treatment.

RESULTS

Two of 9 patients (22%) treated at relatively low dose levels (< or = 1200 mg/m2 on Day 1) demonstrated adrenal cortical insufficiency, as compared with 9 of 11 patients (32%) treated with relatively high doses (> 1200 mg/m2 on Day 1) (P = 0.03 by 1-tailed Fisher's exact test). There appeared to be a cumulative dose-response relationship to the development of glucocorticoid insufficiency, with no instances being observed at doses < 4.8 g/m2 and uniform toxicity occurring at doses > 7.6 g/m2. Long term glucocorticoid insufficiency was present in 1 of 5 patients (20%) tested at an interval of > 90 days after discontinuation of suramin treatment. All instances of glucocorticoid insufficiency were associated with mineralocorticoid insufficiency. Suramin did not affect the absorption or excretion of exogenously administered glucocorticoid in one patient.

CONCLUSIONS

Suramin causes both primary mineralocorticoid and primary glucocorticoid insufficiency. This may occur in a dose-dependent manner. Long term glucocorticoid insufficiency appears to occur in a minority of patients treated with low doses of suramin. Patients receiving high doses of suramin for treatment of advanced carcinoma should receive at least physiologic replacement doses of both mineralocorticoid and glucocorticoid. Higher doses of glucocorticoid may be required in selected patients.

Corticosteroids in tuberculosis

OBJECTIVE

To examine the effects of corticosteroids used for concomitant disease states in patients with latent or active tuberculosis (TB). The role of corticosteroids in the treatment of extrapulmonary TB is also discussed.

DATA SOURCES

A MEDLINE search was conducted for the years 1953-1995. The International Pharmaceutical Abstracts service was also used to conduct an extensive literature review. In addition, relevant articles were cross-referenced to screen for additional information.

STUDY SELECTION/DATA EXTRACTION

During the literature review, emphasis was placed on human studies and individual case reports.

DATA SYNTHESIS

The resurgence of TB in this decade has affected many populations, especially immunocompromised patients. These patients may need corticosteroid therapy for various concomitant diseases that might predispose a patient to develop primary TB infection or reactivate latent TB infection. In appropriate patients, prophylaxis with isoniazid is recommended. Corticosteroid therapy may benefit patients with some forms of extrapulmonary TB. After steroid therapy, improved survival and more rapid reduction of tuberculous symptoms have been noted in cases of tuberculous pleurisy, endobronchial TB, tuberculous meningitis, and tuberculous pericarditis. Corticosteroids may also be useful in controlling both fever and hypersensitivity reactions in pulmonary and extrapulmonary TB, although not routinely used for this purpose.

CONCLUSIONS

Corticosteroids may play an important role in TB infection by promoting reactivation of latent infection. Corticosteroids may modify symptoms of some forms of extrapulmonary TB, although randomized, placebo-controlled studies are needed before corticosteroids will have a definitive place in the standard therapy of TB.

Endocrinologic complications of HIV infection

A variety of endocrine disorders occur in HIV-infected patients. The abnormalities may be a consequence of HIV infection, or may result from opportunistic infections, associated malignancies, illness-associated cytokine production, or use of therapeutic agents. Observations and controversies concerning adrenal, gonadal, thyroidal, and metabolic abnormalities are discussed. Heightened awareness of problems that might otherwise be overlooked will permit timely diagnosis and treatment of identified problems, which will enhance and potentially prolong the lives of people infected with HIV.

Tuberculosis: An Update for Clinicians

Tuberculosis is the most common cause of death due to a single pathogen world wide, and the number of tuberculosis cases in the United States has increased significantly since 1985. Drug-resistant tuberculosis is also increasing, and multidrug-resistant tuberculosis (resistant to isoniazid and rifampin) has fueled deadly epidemics in New York and Florida. The clinical manifestations of tuberculosis in patients with human immunodeficiency virus (HIV) infection are distinctive; chest radiographic findings include primary tuberculosis and an extremely high frequency of extrapulmonary tuberculosis. Promising new diagnostic tests for tuberculosis are based on amplification of mycobacterial DNA by polymerase chain reaction, but they have not yet been adapted to the clinical laboratory. Most tuberculosis patients in the United States should receive initial treatment with isoniazid, rifampin, pyrazinamide, and ethambutol. For drug-susceptible tuberculosis, these drugs are continued for 2 months, followed by isoniazid and rifampin for 4 months, which yields a cure rate of greater than 95%. For isoniazid-resistant organisms, rifampin, pyrazinamide, and ethambutol, with or without isoniazid, can be given for 6 months. For HIV-infected patients with drug-susceptible or isoniazid-resistant tuberculosis, we recommend continuation of therapy for a minimum of 9 months. Most forms of extrapulmonary tuberculosis due to drug-susceptible organisms are treated for 6 months, except for meningeal, miliary, and skeletal tuberculosis, for which a minimum of 12 months of therapy is recommended. To reduce nosocomial transmission of tuberculosis, health cafe facilities should institute administrative controls to reduce exposure to infectious patients, engineering controls to reduce the concentration of infectious droplet nuclei, and personal respiratory protection of health care workers with appropriate masks. Administrative controls are probably the most important part of a tuberculosis infection control program. Health care workers who were recently infected with Mycobacterium tuberculosis can be identified by serial skin testing, and those who convert their skin tests from negative to positive should receive chemoprophylaxis with isoniazid to prevent development of tuberculosis.

Endocrine implications of human immunodeficiency virus infection

Endocrine abnormalities occur frequently in HIV-infected patients. Although the majority of endocrine disorders reflect chronic infection, stress, and malnutrition, some disorders are characteristic of HIV infection or AIDS and deserve particular clinical attention. Identification of HIV patients at risk of frank endocrine disorders, rapid and correct diagnosis, and appropriate management are essential steps to minimize morbidity and mortality. Finally, increasing evidence from in vitro studies suggests that various hormones may influence HIV replication as well as the course of HIV disease and associated disorders. Future studies on the molecular mechanisms of hormones on HIV action and clinical studies on the effects of hormones as adjunctives to established forms of therapy may stimulate development of novel therapeutic strategies that will benefit HIV-infected patients.

Clinical features of adrenal insufficiency in patients with acquired immunodeficiency syndrome

OBJECTIVE

Adrenal insufficiency (AI) is a well known complication of AIDS. However, the clinical and biochemical features of AI in HIV infected patients have not been extensively studied.

DESIGN

A retrospective clinical study.

PATIENTS

We reviewed clinical records of 74 AIDS patients with clinical and/or biochemical indications of AI who underwent Synacthen testing in order to determine adrenocortical function during a 5-year period.

MEASUREMENTS

AI was diagnosed when cortisol levels failed to rise above 496 nmol/l at any time during the test. Cortisol was measured by RIA.

RESULTS

Sixteen patients (22%) were diagnosed with AI. Most were young males and all of them had a known risk factor, principally i.v. drug users. The main complaint was fatigue. Hyponatraemia or hyperkalaemia were uncommon. All of them were severely immunosuppressed, with AIDS-defining conditions from at least 6 months before the diagnosis of AI, and had been diagnosed with at least one disease that has been reported to produce AI in AIDS patients. Survival was poor. Thirteen of these patients (81%) died within 6 months. Basal cortisol levels were lower than 275 nmol/l in 75% of patients with AI but in only 2% of the group of 58 patients who had normal adrenal responses to Synacthen.

CONCLUSIONS

Adrenal insufficiency features in AIDS patients with advanced disease, without specific findings and with a history of previous opportunistic diseases. Basal cortisol values at 0830 h lower than 275 nmol/l are highly suggestive of adrenal insufficiency in patients with AIDS.

Acute adrenocortical failure due to tuberculosis

A 55-year-old woman presented with acute adrenal failure, active pulmonary tuberculosis and an enlarged adrenal mass which was subsequently removed surgically. Histopathologic examination disclosed adrenal tuberculoma. It was concluded that tuberculosis might result not only in chronic adrenocortical insufficiency but also in acute adrenal failure.

Endocrine manifestations of human immunodeficiency virus (HIV) infection

Endocrine manifestations of HIV infection include both pathological changes and disturbances in function. Mechanisms include direct infection of glands by HIV or opportunistic organisms, infiltration by neoplasms, side effects of drugs, and production of humoral factors that may alter metabolism. The adrenal gland is most often affected, but virtually every endocrine system may be involved. Dysfunction is often subtle, with symptoms overlapping those of the HIV infection itself. Endocrine manifestations may be found at any time in the course of the disease, from the asymptomatic HIV-positive stage through full-blown AIDS. Optimal management of these patients may include a careful search for, and appropriate treatment of, associated endocrine abnormalities.

Diagnostic and therapeutic problems in a case of adrenal tuberculosis and acute Addison's disease

A case of adrenal tuberculosis with acute Addison's disease is presented. The case showed diagnostic and therapeutic problems, the latter concerning the untoward effects due to metabolic interferences and pharmacologic interactions among antitubercular drugs, substitutive corticosteroid therapy and hepatic metabolism. The side-effects, interactions and metabolism of drugs used during the course of disease are discussed.

Addisonian crisis induced by treatment with rifampicin

A patient with spinal tuberculosis and subclinical adrenal tuberculosis who developed acute Addisonian crisis on starting anti-tuberculosis therapy including rifampicin is reported. The possibility that many patients with tuberculosis have adrenal involvement with limited hormonal reserve and that they may develop incipient adrenal failure on commencing treatment is discussed.