Symptomatic hypocalcemia and hypomagnesemia with renal magnesium wasting associated with pentamidine therapy in a patient with AIDS

An overview of diagnosis and management of drug-induced hypomagnesemia

Magnesium (Mg) is commonly addressed as the "forgotten ion" in medicine. Nonetheless, hypomagnesemia should be suspected in clinical practice in patients with relevant symptomatology and also be considered a predisposing factor for the development of other electrolyte disturbances. Furthermore, chronic hypomagnesemia has been associated with diabetes mellitus and cardiovascular disease. Hypomagnesemia as a consequence of drug therapy is relatively common, with the list of drugs inducing low serum Mg levels expanding. Culprit medications linked to hypomagnesemia include antibiotics (e.g. aminoglycosides, amphotericin B), diuretics, antineoplastic drugs (cisplatin and cetuximab), calcineurin inhibitors, and proton pump inhibitors. In recent years, the mechanisms of drug-induced hypomagnesemia have been unraveled through the discovery of key Mg transporters in the gut and kidney. This narrative review of available literature focuses on the pathogenetic mechanisms underlying drug-induced hypomagnesemia in order to increase the insight of clinicians toward early diagnosis and effective management.

Hypomagnesemia in the Cancer Patient

Hypomagnesemia is a common medical problem that contributes to the morbidity and mortality of patients with cancer. This review summarizes magnesium physiology and highlights the mechanisms underlying magnesium disturbances due to cancer and cancer treatment. The causes of hypomagnesemia can be categorized according to the pathophysiologic mechanism: decreased intake, transcellular shift, gastrointestinal losses, and kidney losses. Patients with cancer are at risk for opportunistic infections, frequently experience cardiovascular complications, and often receive classes of medications that cause or exacerbate hypomagnesemia. Also, cancer-specific therapies are responsible for hypomagnesemia, including platinum-based chemotherapy, anti-EGF receptor mAbs, human EGF receptor-2 target inhibitors (HER2), and calcineurin inhibitors. Urinary indices, such as the fractional excretion of magnesium, can provide useful information about the etiology. The management of hypomagnesemia depends on the magnitude of hypomagnesemia and the underlying cause. We recommended checking serum magnesium at the beginning of treatment and as part of routine monitoring throughout cancer treatment. Opportunities exist for potential research and practice improvement, including further characterization of hypomagnesemia regarding the clinical effect on cancer outcomes, preventing hypomagnesemia in patients receiving high-risk anticancer agents, and developing effective therapeutic strategies.

Safety profile of the concomitant use of foscarnet and aerosolized pentamidine in allogeneic hematopoietic stem cell transplantation recipients

BACKGROUND

Concomitant use of foscarnet and intravenous pentamidine can very frequently cause severe hypocalcemia. However, it is unknown whether aerosolized pentamidine has a similar adverse interaction with foscarnet. The present study was aimed at examining the safety profile of concomitantly used foscarnet and aerosolized pentamidine in patients receiving allogeneic hematopoietic stem cell transplantation.

METHODS

Data from allogeneic hematopoietic stem cell recipients who had been administered foscarnet therapy for over 7 days were analyzed. We compared electrolyte abnormalities and serum creatinine level between patients who received aerosolized pentamidine concomitantly and those who did not.

RESULTS

A total of 84 consecutive patients and 135 episodes of foscarnet therapy between May 2011 and April 2016 were evaluable. Of these 135 episodes, 25 episodes of therapy included concurrent therapy with 300 mg dose of aerosolized pentamidine once a month (pentamidine group) and 110 episodes did not (non-pentamidine group). The incident rates of grade 3/4 hypocalcemia did not significantly differ between the pentamidine and non-pentamidine groups (P = .207; 0/25 [0%] vs 10/110 [9.1%], respectively). In addition, we observed no significant difference in the incident rates of grade 3/4 serum creatinine increase between the two groups (P = 1.00; 0/25 [0%] vs 4/110 [3.6%], respectively).

CONCLUSION

Our results suggest that the drug interactions between foscarnet and aerosolized pentamidine may not be clinically significant.

The role of magnesium sulfate in the intensive care unit

Magnesium (Mg) has been developed as a drug with various clinical uses. Mg is a key cation in physiological processes, and the homeostasis of this cation is crucial for the normal function of body organs. Magnesium sulfate (MgSO4) is a mineral pharmaceutical preparation of magnesium that is used as a neuroprotective agent. One rationale for the frequent use of MgSO4 in critical care is the high incidence of hypomagnesaemia in intensive care unit (ICU) patients. Correction of hypomagnesaemia along with the neuroprotective properties of MgSO4 has generated a wide application for MgSO4 in ICU.

Magnesium in man: implications for health and disease

Magnesium (Mg(2+)) is an essential ion to the human body, playing an instrumental role in supporting and sustaining health and life. As the second most abundant intracellular cation after potassium, it is involved in over 600 enzymatic reactions including energy metabolism and protein synthesis. Although Mg(2+) availability has been proven to be disturbed during several clinical situations, serum Mg(2+) values are not generally determined in patients. This review aims to provide an overview of the function of Mg(2+) in human health and disease. In short, Mg(2+) plays an important physiological role particularly in the brain, heart, and skeletal muscles. Moreover, Mg(2+) supplementation has been shown to be beneficial in treatment of, among others, preeclampsia, migraine, depression, coronary artery disease, and asthma. Over the last decade, several hereditary forms of hypomagnesemia have been deciphered, including mutations in transient receptor potential melastatin type 6 (TRPM6), claudin 16, and cyclin M2 (CNNM2). Recently, mutations in Mg(2+) transporter 1 (MagT1) were linked to T-cell deficiency underlining the important role of Mg(2+) in cell viability. Moreover, hypomagnesemia can be the consequence of the use of certain types of drugs, such as diuretics, epidermal growth factor receptor inhibitors, calcineurin inhibitors, and proton pump inhibitors. This review provides an extensive and comprehensive overview of Mg(2+) research over the last few decades, focusing on the regulation of Mg(2+) homeostasis in the intestine, kidney, and bone and disturbances which may result in hypomagnesemia.

Hypomagnesemia: a clinical perspective

Although magnesium is involved in a wide spectrum of vital functions in normal human physiology, the significance of hypomagnesemia and necessity for its treatment are under-recognized and underappreciated in clinical practice. In the current review, we first present an overview of the clinical significance of hypomagnesemia and normal magnesium metabolism, with a focus on renal magnesium handling. Subsequently, we review the literature for both congenital and acquired hypomagnesemic conditions that affect the various steps in normal magnesium metabolism. Finally, we present an approach to the routine evaluation and suggested management of hypomagnesemia.

Magnesium homeostasis and hypomagnesemia in children with malignancy

Hypomagnesemia is not uncommon among children with malignancies. It is especially seen in association with certain medications and can be further complicated by the presence of diarrhea and malnutrition. Severe hypomagnesemia may cause disturbances in the neuromuscular and cardiovascular systems. All patients with hypomagnesemia should be supplemented with the mineral, and urgent treatment is indicated when serum magnesium decreases below 1.0 mg/dl, a level under which symptoms may develop. This review addresses the essentials of magnesium physiology, and pathophysiology of hypomagnesemia, its etiologies, clinical manifestations and ways to treat it, with an emphasis on the child with hematologic/oncologic disorders.

Drug-induced alterations in Mg2+ homoeostasis

Magnesium (Mg2+) balance is tightly regulated by the concerted actions of the intestine, bone and kidneys. This balance can be disturbed by a broad variety of drugs. Diuretics, modulators of the EGFR (epidermal growth factor receptor), proton pump inhibitors, antimicrobials, calcineurin inhibitors and cytostatics may all cause hypomagnesaemia, potentially leading to tetany, seizures and cardiac arrhythmias. Conversely, high doses of Mg2+ salts, frequently administered as an antacid or a laxative, may lead to hypermagnesaemia causing various cardiovascular and neuromuscular abnormalities. A better understanding of the molecular mechanisms underlying the adverse effects of these medications on Mg2+ balance will indicate ways of prevention and treatment of these adverse effects and could potentially provide more insight into Mg2+ homoeostasis.

Renal involvement in leishmaniasis: a review of the literature

Leishmaniasis, an infectious disease endemic in tropical, Asian and southern European countries, is caused by obligate intramacrophage protozoa and is transmitted through the bite of infected female sandflies. More than 20 leishmanial species are responsible for four main clinical syndromes: cutaneous leishmaniasis; mucocutaneous leishmaniasis; visceral leishmaniasis, also known as kala-azar, and post-kala-azar dermal leishmaniasis. Visceral leishmaniasis can present with varying clinical features and the kidney can also be involved. Both glomerular and tubular function can be altered and patients can develop proteinuria, haematuria, abnormalities in urinary concentration and acidification and acute and chronic renal insufficiency. Not only the disease itself but also the therapy administered might be responsible for the renal involvement in kala-azar. Indeed, some of the agents with efficiency against visceral leishmaniasis, such as pentavalent antimonial drugs, amphotericin B, pentamidine, miltefosine, paromomycin and simataquine, may be associated with a high risk of renal toxicity. In this article, the literature on renal involvement in visceral leishmaniasis is reviewed.

Nephrotoxicity as a complication of antiretroviral therapy

Since 1984, human immunodeficiency virus-associated nephropathy has been established as a clinical entity that presents with nephrotic syndrome and progressive kidney failure. The pathological description is usually consistent with a collapsing form of focal segmental glomerulosclerosis. Podocytes and renal tubular cells have been proposed as a reservoir for the human immunodeficiency virus. This nephropathy is the third leading cause of end-stage renal disease in the population of African descent. It is documented that highly active antiretroviral therapy (HAART) successfully reverses or at least controls nephropathy in HIV-positive patients. The success of the treatment of HIV nephropathy now poses 2 problems to nephrologists: (1) an increased population of HIV-positive patients with chronic kidney disease not yet on dialysis and (2) potential nephrotoxicity of antiretroviral medications as well as medications used to treat opportunistic infections. HAART is defined by the combination of 2 reverse transcriptase inhibitors with a protease inhibitor or 3 reverse-transcriptase inhibitors. Many of these antiretrovirals have well-defined nephrotoxic effects. The objective of this text is to review data pertaining to some of the most common antiretrovirals (ARTs) and include information regarding nephrotoxicity of the medications frequently used to combat opportunistic infections. ARTs included in the review are (1) nucleoside reverse-transcriptase inhibitors (zidovudine and didanosine), (2) nucleotide reverse transcriptase inhibitors (adefovir and tenofovir), (3) the protease inhibitors (indinavir and saquinavir), and (4) the HIV fusion inhibitors.

Alterations in electrolyte equilibrium in patients with acute leukemia

BACKGROUND AND AIM

A wide array of disturbances in electrolyte equilibrium is commonly seen in patients with acute leukemia (AL). These abnormalities present a potential hazard in these patients, as that of enhancing the cardiotoxic effects of certain chemotherapeutic regimens. The literature dealing with AL-related electrolyte abnormalities and their interactions in leukemic patients was reviewed.

DATA SYNTHESIS

Sources included MEDLINE and EMBASE. The search strategy was based on the combination of 'acute leukemia', 'electrolyte abnormalities', 'acid-base disorders', 'potassium', 'sodium', 'magnesium', 'calcium', and 'phosphorus'. References of retrieved articles were also screened. A decrease in serum potassium, mainly owing to lysozyme-induced tubular damage, appears to be one of the most frequent and potentially hazardous abnormalities. Other clinically significant metabolic perturbations include hyponatremia and hypercalcemia.

CONCLUSION

A broad spectrum of electrolyte abnormalities is encountered in the clinical setting of AL, which are related to the disease process per se and/or to the therapeutic interventions. Clinicians should be vigilant for early detection and appropriate management of these disorders before the initiation of chemotherapy regimens as well as during treatment.

Drug-induced hypomagnesaemia : scope and management

Nearly 50 medications have been implicated as inducing hypomagnesaemia, sometimes based on insufficient data regarding clinical significance and frequency of occurrence. In fact, clinical effects attributed to hypomagnaesemia have been reported in only 17 of these drugs. A considerable amount of literature relating to individual drugs has been published, yet a comprehensive overview of this issue is not available and the hypomagnesaemic effect of a drug could be either overemphasised or under-rated. In addition, there are neither guidelines regarding treatment, prevention and monitoring of drug-induced hypomagnesaemia nor agreement as to what serum level of magnesium may actually be defined as 'hypomagnesaemia'. By compiling data from published papers, electronic databases, textbooks and product information leaflets, we attempted to assess the clinical significance of hypomagnesaemia induced by each drug. A practical approach for managing drug-induced hypomagnesaemia, incorporating both published literature and personal experience of the physician, is proposed. When drugs classified as inducing 'significant' hypomagnesaemia (cisplatin, amphotericin B, ciclosporin) are administered, routine magnesium monitoring is warranted, preventive treatment should be considered and treatment of hypomagnesaemia should be initiated with or without overt clinical manifestations. In drugs belonging to the 'potentially significant' category, among which are amikacin, gentamicin, laxatives, pentamidine, tobramycin, tacrolimus and carboplatin, magnesium monitoring is justified when either of the following occurs: clinical manifestations are apparent; persistent hypokalaemia, hypocalcaemia or alkalosis are present; other precipitating factors for hypomagnesaemia coexist; or treatment is with more than one potentially hypomagnesaemic drug. No preventive treatment is required and treatment should be initiated only if hypomagnesaemia is accompanied by symptoms or clinically significant relevant laboratory findings. In those drugs whose hypomagnesaemic effect is labelled as 'questionable', including furosemide and hydrochlorothiazide, routine monitoring and treatment are not required.

HIV infection--a risk factor for osteoporosis

Osteopenia and osteoporosis have recently been described as complications of antiretroviral therapy in HIV-infected patients. The advent of highly active antiretroviral therapy in conjunction with improved standard antiviral and antibiotic regimens has dramatically changed the clinical course of HIV infection, resulting in prolonged survival. The pathogenesis and role of each individual medication are poorly understood. Avascular necrosis has also been described in AIDS patients receiving or not receiving antiretroviral therapy. This article is a clinically focused review of the literature on osteopenia, osteoporosis, and mineral metabolism related to HIV infection. In patients with HIV infection, the risks of osteopenia and osteoporosis are not very clear. The suggested risk factors for the development of osteopenia are use of protease inhibitors, longer duration of HIV infection, high viral load, high lactate levels, low bicarbonate levels, raised alkaline phosphatase level, and lower body weight before antiretroviral therapy. There have also been a few case reports of pathologic fractures in AIDS patients with antiretroviral therapy-induced osteopenia and osteoporosis. The underlying mechanism triggering bone loss in HIV-infected patients is unknown. The proinflammatory cytokines tumor necrosis factor and interleukin-6 have been found to be constitutionally produced in increased amounts in HIV-positive individuals, and they may have a role in osteoclast activation and resorption. Serum markers of bone formation are decreased and resorption is increased in patients with advanced clinical disease. Hypocalcemia, hypercalcemia, and abnormalities of the parathyroid hormone axis have been described in HIV infection. Histomorphometric analyses have shown altered bone remodeling in HIV-infected patients when compared with controls. Patients with known risk factors for osteoporosis-advancing age, low body weight, and prolonged duration of HIV infection-and those receiving protease inhibitor treatment should be considered for dual x-ray absorptiometry imaging. If bone mineral density is osteopenic or osteoporotic, then the patient should also be screened for other known medical causes of osteoporosis and consider treatment with a bisphosphonate or, if hypogonadal, testosterone replacement under close monitoring.

Magnesium in disease: a review with special emphasis on the serum ionized magnesium

This review deals with the six main clinical situations related to magnesium or one of its fractions, including ionized magnesium: renal disease, hypertension, pre-eclampsia, diabetes mellitus, cardiac disease, and the administration of therapeutic drugs. Issues addressed are the physiological role of magnesium, eventual changes in its levels, and how these best can be monitored. In renal disease mostly moderate hypermagnesemia is seen; measuring ionized magnesium offers minimal advantage. In hypertension magnesium might be lowered but its measurement does not seem relevant. In the prediction of severe pre-eclampsia, elevated ionized magnesium concentration may play a role, but no unequivocal picture emerges. Low magnesium in blood may be cause for, or consequence of, diabetes mellitus. No special fraction clearly indicates magnesium deficiency leading to insulin resistance. Cardiac diseases are related to diminished magnesium levels. During myocardial infarction, serum magnesium drops. Total magnesium concentration in cardiac cells can be predicted from levels in sublingual or skeletal muscle cells. Most therapeutic drugs (diuretics, chemotherapeutics, immunosuppressive agents, antibiotics) cause hypomagnesemia due to increased urinary loss. It is concluded that most of the clinical situations studied show hypomagnesemia due to renal loss, with exception of renal disease. Keeping in mind that only 1% of the total body magnesium pool is extracellular, no simple measurement of the real intracellular situation has emerged; measuring ionized magnesium in serum has little added value at present.

Renal complications in HIV disease

Renal consequences of HIV disease are diverse: some unique attributable to HIV infection per se and some coincidental reflecting the nature and severity of underlying primary illness. In addition, renal sequelae may also be iatrogenic, owing to a variety of therapeutic agents employed in the management of HIV infection. Renal failure from any cause, both reversible (acute) and irreversible (ESRD), contributes greatly to morbidity and mortality in HIV-infected patients. An understanding of the spectrum of renal derangements is essential for clinicians to manage patients with HIV disease better.

Hypocalcemic emergencies

Chronic hypocalcemia occurs frequently, although emergent hypocalcemia does not. When hypocalcemia is suspected, verification of ionized hypocalcemia is required and an etiopathologic search warranted. Etiology-specific therapy is suggested, although at times emergent intravenous calcium is indicated. Long-term nonspecific therapy includes oral calcium and vitamin D supplementation.

Magnesium deficiency: pathophysiologic and clinical overview

Magnesium is an essential cation, involved in many enzymatic reactions, as a cofactor to adenosine triphosphatases. It is critical in energy-requiring metabolic processes, as well as protein synthesis and anaerobic phosphorylation. Serum Mg concentration is maintained within a narrow range by the kidney and small intestine since under conditions of Mg deprivation both organs increase their fractional absorption of Mg. If Mg depletion continues, the bone store contributes by exchanging part of its content with extracellular fluid (ECF). The serum Mg can be normal in the presence of intracellular Mg depletion, and the occurrence of a low level usually indicates significant Mg deficiency. Hypomagnesemia is frequently encountered in hospitalized patients and is seen most often in patients admitted to intensive care units. The detection of Mg deficiency can be increased by measuring Mg concentration in the urine or using the parenteral Mg load test. Hypomagnesemia may arise from various disorders of the gastrointestinal tract, conditions affecting Mg renal handling, or cellular redistribution of Mg. The gastrointestinal causes include the following: protein-calorie malnutrition, the intravenous administration of Mg-free fluids and total parenteral nutrition, chronic watery diarrhea and steatorrhea, short bowel syndrome, bowel fistula, continuous nasogastric suctioning, and, rarely, primary familial Mg malabsorption. The renal causes include Bartter's and Gitelman's syndrome, post obstructive diuresis, post acute tubular necrosis, renal transplantation, and interstitial nephropathy. Many therapeutic agents cause renal Mg wasting and subsequent deficiency. These include loop and thiazide diuretics, aminoglycosides, cisplatin, pentamidine, and foscarnet. Magnesium deficiency is seen frequently in alcoholics and diabetic patients, in whom a combination of factors contributes to its pathogenesis. Hypomagnesemia is known to produce a wide variety of clinical presentations, including neuromuscular irritability, cardiac arrhythmias, and increased sensitivity to digoxin. Refractory hypokalemia and hypocalcemia can be caused by concomitant hypomagnesemia and can be corrected with Mg therapy. The dose and route of administration of Mg in the treatment of hypomagnesemia is dictated by the clinical presentation, the degree of Mg deficiency, and the renal function.

Aetiology and pathogenesis of hormonal and metabolic disorders in HIV infection

Many hormonal and metabolic disturbances are documented in HIV infection, the most important of which is the wasting syndrome associated with progressive HIV infection. We are only now beginning to understand the pathogenesis of these disturbances. In rare cases, infiltration of endocrine tissue by secondary infectious or malignant processes is the underlying cause of hormonal insufficiency. In most instances, however, hypofunction is secondary to the well-known effects of severe illness. Similarly, hyperfunction of the adrenal axis along with many of the derangements in substrate metabolism are also likely to be secondary to severe illness, perhaps through activation of cytokines and other molecules. Specific disturbances in asymptomatic patients are more difficult to document and may represent unique and as yet unexplained manifestations of HIV disease. Hypermetabolism and depletion of lean body mass are most profound in the acutely ill patient with active secondary infection. At this stage, the HIV-infected patient is in a catabolic state and adaptive mechanisms which normally decrease energy expenditure and preserve lean body mass are either overridden or not operative. Strategies to reverse the catabolic state and diminish wasting are only now being developed.

Torsade de pointes and elevated magnesium and calcium requirements associated with intravenous pentamidine

We present a report of markedly elevated calcium and magnesium requirements in an AIDS patient receiving central venous nutrition. These increased requirements were attributed to urinary magnesium losses associated with intravenous pentamidine therapy. The combination of intravenous pentamidine and electrolyte abnormalities resulted in the development of the dysrhythmia, torsade de pointes, in the patient. A review of literature presenting similar cases is included. Nutrition practitioners should be aware of the often prolonged effect of intravenous pentamidine on magnesium and calcium homeostasis so that adequate supplementation will be provided, perhaps preventing the development of life-threatening torsade de pointes.

Magnesium homeostasis and clinical disorders of magnesium deficiency

OBJECTIVE

To survey the causes of clinical hypomagnesemia and Mg deficiency. The relationship of hypomagnesemia to digitalis toxicity, congestive heart failure, arrhythmias, and acute myocardial infarction is discussed, as is the clinical interrelationship of Mg and K concentrations, the principal intracellular cations.

DATA SOURCES

A MEDLINE search and retrieval was used to identify relevant references.

STUDY SELECTION

Clinical reports, as well as studies, were selected for this review.

DATA EXTRACTION

There were very few placebo-controlled clinical studies. Clinical observations were related primarily to compilation of series in which Mg was administered and clinical results reported. In addition, conclusions derived from review articles on the subject of clinical Mg depletion were used.

DATA SYNTHESIS

Clinical diagnosis of Mg deficiency is ascertained most expeditiously by estimating serum Mg concentrations. Although available on order by physicians, the lack of routine serum Mg analysis as part of the "electrolyte panel" impedes the diagnosis of clinical Mg deficiency. Renal loss of Mg resulting from the widespread use of loop diuretics is responsible for significant numbers of patients with Mg deficiency and hypomagnesemia. Life-threatening cardiac arrhythmias and seizures represent the most serious manifestations of clinical hypomagnesemia and Mg depletion. In the most critically ill patients, treatment with intravenous Mg is recommended. Oral repletion of Mg is reserved for the less critically ill hospitalized patients and ambulatory patients. Close attention must be paid to optimizing K replenishment in hypokalemic patients by concurrent treatment of any accompanying hypomagnesemia to avoid the problem of refractory K repletion.

CONCLUSIONS

Hypomagnesemia is one of the most frequent serum electrolyte abnormalities in current clinical practice. Routine inclusion of serum Mg analysis in the electrolyte panel will enhance the clinical recognition and treatment of hypomagnesemic Mg-depleted patients. Failure to respond to treatment of recurrent ventricular tachycardia/fibrillation to usual antiarrhythmic therapy in patients with acute myocardial infarction, idiopathic dilated cardiomyopathy, and congestive heart failure should alert the clinician to consider administering intravenous Mg. Repair of coexisting hypomagnesemia in hypokalemic patients is essential to avoid the problem of refractory K repletion caused by coexisting Mg depletion. More controlled clinical studies of Mg deficiency are necessary to ascertain the cost-effectiveness of Mg replacement therapy.

Magnesium and its therapeutic uses: a review

Magnesium has been reported as an effective medical therapy in an expanding array of conditions. Evidence investigating magnesium's use is presented, with a number of studies suggesting it should be seriously considered in such conditions as ischemic heart disease, cardiac arrhythmias, and asthma. Magnesium balance and metabolism are briefly reviewed, and then various hypotheses are presented that may explain magnesium's physiologic mechanisms of action, most likely involving calcium and potassium flux across cellular membranes in smooth muscle. In a number of the conditions to be discussed, it has been uncertain whether magnesium administration serves the purpose of merely correcting an underlying deficiency state or of utilizing a specific pharmacologic effect of magnesium. Magnesium deficiency is a relatively common condition, and predisposing factors as well as recent methods for assessing total body stores of magnesium are discussed. Physicians should be familiar with the numerous conditions and therapeutics that are risk factors for an underlying magnesium deficiency and in which empiric magnesium replacement should be considered. Guidelines for administration of parenteral magnesium are presented with specific focus on the low risk of adverse effects, as suggested by the large and rapid dosing regimens used in many of the clinical studies discussed here.

Endocrine manifestations of AIDS

The endocrine manifestations of AIDS are now appreciated to involve virtually any of the endocrine organs. Some of these manifestations are subtle and clinically not apparent. Others, like adrenal involvement, can eventuate, although rarely, into frank glandular insufficiency. This Endocrine Rounds case illustrates a number of endocrine manifestations of AIDS and discusses their involvement from clinical and pathophysiologic aspects.

Case report: pentamidine and polymorphic ventricular tachycardia revisited

Pentamidine isethionate has been associated with ventricular tachyarrhythmias, including torsade de pointes. This article reports two cases of this complication and reviews all reported cases to date. Pentamidine-induced torsade de pointes may be related to serum magnesium levels and hypomagnesemia may synergistically induce torsade. Torsade de pointes occurred after an average of 10 days of treatment with pentamidine. In these patients, no other acute side effects of pentamidine were observed. Torsade de pointes can be treated when recognized early, possibly without discontinuation of pentamidine. When QTc interval prolongation is observed, early magnesium supplementation is advocated.