Severe hyponatremia and hyperkalemia induced by trimethoprim-sulfamethoxazole in patients with Pneumocystis carinii pneumonia

Low-dose trimethoprim-sulfamethoxazole for the treatment of Pneumocystis jirovecii pneumonia (LOW-TMP): protocol for a phase III randomised, placebo-controlled, dose-comparison trial

INTRODUCTION

Pneumocystis jirovecii pneumonia (PJP) is an opportunistic infection of immunocompromised hosts with significant morbidity and mortality. The current standard of care, trimethoprim-sulfamethoxazole (TMP-SMX) at a dose of 15-20 mg/kg/day, is associated with serious adverse drug events (ADE) in 20%-60% of patients. ADEs include hypersensitivity reactions, drug-induced liver injury, cytopenias and renal failure, all of which can be treatment limiting. In a recent meta-analysis of observational studies, reduced dose TMP-SMX for the treatment of PJP was associated with fewer ADEs, without increased mortality.

METHODS AND ANALYSIS

A phase III randomised, placebo-controlled, trial to directly compare the efficacy and safety of low-dose TMP-SMX (10 mg/kg/day of TMP) with the standard of care (15 mg/kg/day of TMP) among patients with PJP, for a composite primary outcome of change of treatment, new mechanical ventilation, or death. The trial will be undertaken at 16 Canadian hospitals. Data will be analysed as intention to treat. Primary and secondary outcomes will be compared using logistic regression adjusting for stratification and presented with 95% CI.

ETHICS AND DISSEMINATION

This study has been conditionally approved by the McGill University Health Centre; Ethics approval will be obtained from all participating centres. Results will be submitted for publication in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT04851015.

Analysis of the Clinical Characteristics of Hyponatremia Induced by Trimethoprim/Sulfamethoxazole

BACKGROUND

Trimethoprim-sulfamethoxazole (TMP/SMX) causes hyperkalemia, and hyponatremia caused by TMP/SMX is a challenge for clinicians. We described the clinical features of hyponatremia induced by TMP/SMX after collecting cases.

SUMMARY

The median age of the 24 patients (10 males and 14 females) was 67 years (range: 28-90 years). Hyponatremia induced by TMP/SMX manifested as nausea (41.7%) and vomiting (29.2%) or asymptomatic hyponatremia (20.8%). The median duration of hyponatremia was 5 days (range: 3-10 days). The median serum sodium concentration was 118 mmol/L (range: 101-128.1 mmol/L). The serum sodium levels gradually returned to the normal range at 4 days (median; range: 2-14 days) after withdrawing TMP/SMX.

KEY MESSAGES

TMP/SMX-induced hyponatremia is a rare and serious adverse reaction. Clinicians should be aware of electrolyte disturbances caused by TMP/SMX and should always consider electrolyte monitoring.

Clinical manifestations and associated factors in acquired hypoaldosteronism in endocrinological practice

INTRODUCTION

Hypoaldosteronism can be congenital or acquired, isolated or part of primary adrenal insufficiency, and caused by an aldosterone deficit, resistance, or a combination of both. Reduced mineralocorticoid action can induce a decrease in urine K+ and H+ excretion and an increase in urine Na+ excretion, leading to hyperkalemia, and/or hyponatremia, often combined with metabolic acidosis. We aimed to characterize the clinical manifestations of hypoaldosteronism, and their associated factors.

METHODS

Retrospective analysis of 112 episodes of hypoaldosteronism diagnosed in 86 adult patients from 2012-2019 by the Endocrinology and Nutrition Department of a tertiary hospital. The frequency of hyperkalemia, hypovolemic hyponatremia (HH) and metabolic acidosis (MA), and their associated factors were evaluated.

RESULTS

Patients had a median age of 77 [65 - 84], 55.4% were male. 94.6% cases showed hyperkalemia, 54.5% HH, and 60.3% MA. The mean serum K+ of all cases was 5.4 ± 0.5 mmol/L, Na+: 132.1 ± 6.3 mmol/L, HCO3: 22.6 ± 3.3 mmol/L. Hypoaldosteronism was isolated in the majority of cases: only 6/112 (5%) had primary adrenal insufficiency. Hypovolemia was associated with hyponatremia and a more florid clinical presentation. HH was associated with a combined presence of aldosterone-lowering and mineralocorticoid resistance factors. MA was associated with the presence of mineralocorticoid resistance factors.

CONCLUSIONS

Hypoaldosteronism in adult endocrinological clinical practice is primarily isolated, and acquired. It predisposes not only to the development of hyperkalemia and MA, but also to that of HH. Hypoaldosteronism must be considered in the differential diagnosis of HH with urinary sodium wasting.

Prevalence and impact on outcome of sodium and potassium disorders in patients with community-acquired pneumonia: A retrospective analysis

INTRODUCTION

Disorders of sodium and potassium are common and predictors of adverse outcome. Prevalence and impact on outcome of hypokalemia, hyperkalemia, hyponatremia and hypernatremia were investigated in emergency patients with community-acquired pneumonia (CAP).

METHODS

Patients ≥18 years presenting to our emergency department between January 1st 2017 and December 31st 2018 with on-admission electrolyte measurements were included. Chart reviews were performed to identify patients with CAP.

RESULTS

19.948 cases had measurements of sodium and potassium of which 469 had CAP (2.4%). Prevalence of hypo- and hypernatremia was significantly increased in patients with compared to those without CAP (hyponatremia: 28.8% vs. 10.5% respectively, p<0.0001; hypernatremia: 1.9% vs. 0.6% respectively, p=0.002). The prevalence of hypo- and hyperkalemia was significantly higher in patients with than without CAP (hypokalemia 15.6% vs. 11.4% respectively, p=0.004; hyperkalemia: 4.5% vs. 2.0% respectively, p=0.001). Hyponatremia was significantly associated with longer hospital stay in patients with CAP (regression coefficient 0.194, standard error 0.079, p=0.015). None of the investigated electrolyte disorders were predictive of 30-day re-admission and 180-day pneumonia recurrence rates. Use of loop diuretics was an independent predictor for 30-day re-admission (OR 2.351 (1.099-5.03). p=0.028). Pneumonia Severity Index (PSI) risk class was an independent predictor of 180-day pneumonia recurrence (OR 1.494 (1.022-2.184), p=0.038).

CONCLUSION

Dysnatremias and dyskalemias are common findings complicating CAP in emergency patients. Prevalence of hyponatremia was highest followed by hypokalemia. Hyponatremia was an independent predictor of prolonged length of hospital stay. Loop diuretic use was associated with 30-day readmission and PSI risk class with 180-day pneumonia recurrence.

Trimethoprim-sulfamethoxazole-induced hyponatremia in an elderly lady with Achromobacter xylosoxidans pneumonia: Case report and insights into mechanism

RATIONALE

Hyponatremia occurs frequently in the hospital setting and may be attributable to a host of etiologies. Drugs are frequently implicated. Trimethoprim-sulfamethoxazole (TMP/SMX) represents a well-recognized pharmacologic precipitant of drug-induced hyponatremia, with several reports extant in the retrievable literature. Nephrologists thus debate the mechanisms giving rise to TMP/SMX-induced hyponatremia and the precise mechanism by which treatment with TMP/SMX generates reductions of serum sodium concentration remain controversial. The agent has a well-known effect of antagonizing the effects of aldosterone upon the distal nephron. Renal salt wasting and the syndrome of inappropriate antidiuretic hormone secretion represent implicated mechanistic intermediaries in TMP/SMX-induced hyponatremia.

PATIENT CONCERNS

The patient endorsed no explicit concerns.

DIAGNOSES

We describe the case of an 83-year-old female clinically diagnosed with pneumonia found to have an initial serum sodium in the range of 130 to 134 mEq/L consistent with mild hyponatremia upon admission. Sputum cultures grew Achromobacter xylosoxidans susceptible to TMP/SMX. The patient's serum sodium concentration precipitously decline following institution of treatment with TMP/SMX to 112 to 114 mEq/L during the course of 5 days.

INTERVENTIONS

Severe hyponatremia proved recalcitrant to initial therapy with supplemental salt tabs and standard doses of the vasopressin receptor antagonist tolvaptan.

OUTCOMES

Escalating doses of tolvaptan increased the patient's sodium to 120 to 124 mEq/L. The patient was transferred to another hospital for further management. During her stay, the patient did not exhibit frank or obvious clinical features consistent with hyponatremia nor readily appreciable evidence of volume depletion.

LESSONS

TMP/SMX represents a frequent, though underreported cause of hyponatremia in the hospital setting several authors believe natriuresis may represent the most common mechanism underlying TMP/SMX-induced hyponatremia. Evidence implicating natriuresis to be mechanistic in TMP/SMX-induced hyponatremia include clinically appreciable hypovolemia and resolution of hyponatremia with oral or intravenous salt repletion. Salt repletion failed to monotherapeutically enhance our patient's hyponatremiadisfavoring renal salt wasting as originately mechanistic. Contemporaneous refractoriness of serum sodium to fluid restriction nor standard doses of tolvaptan confounded our initial attempts to mechanistically attribute the patient's hyponatremia to a specific cause. Clinical euvolemia and rapid response of hyponatremia to exceptionally high doses of tolvaptan strongly favors syndrome of inappropriate antidiuretic hormone to represent the chief mechanism by which TMP/SMX exacerbates hyponatremia.

Trimethoprim-associated electrolyte and acid-base abnormalities

INTRODUCTION

The antimicrobial trimethoprim is structurally related to potassium-sparing diuretics and may consequently lead to derangements in electrolyte and acid-base balance. Since no report so far analyzed the literature documenting individual cases with electrolyte and acid-base derangements induced by trimethoprim, a systematic review was carried out.

EVIDENCE ACQUISITION

We retained 53 reports documenting 68 cases (42 males and 26 females 23 to 96 years of age) of electrolyte or acid-base derangements occurring on trimethoprim for about 5 days.

EVIDENCE SYNTHESIS

One hundred five electrolyte imbalances were detected in the 68 patients: hyperkalemia (>5.0 mmol/L) in 62 (91%), hyponatremia (<135 mmol/L) in 29 (43%) and metabolic acidosis (pH<7.38 and bicarbonate <19 mmol/L) in 14 (21%) cases. Following possible predisposing factors for electrolyte and acid-base abnormalities were found in 54 (79%) patients: high-dose trimethoprim, comedication with drugs that have been associated with electrolyte and acid-base derangements, preexisting kidney disease, age ≥80 years and diabetes mellitus.

CONCLUSIONS

High-dose trimethoprim, comedicated with drugs that have been associated with electrolyte and acid-base derangements, poor kidney function, age ≥80 years and diabetes mellitus predispose to trimethoprim-associated electrolyte and acid-base abnormalities. Clinicians must recognize patients at risk, possibly avoid drug combinations that may worsen the problem and monitor the laboratory values.

Hyponatremia With Intravenous Sulfamethoxazole/Trimethoprim in Children

Background: Intravenous (IV) sulfamethoxazole/trimethoprim (SMX/TMP) has been associated with hyponatremia in adults. Objective: The primary objective was to identify the number of patients with a serum sodium <135 mEq/L. Secondary objectives between the hyponatremic versus nonhyponatremic groups included demographic comparisons, median serum sodium concentrations, SMX/TMP cumulative dose, number of diuretics, and other medications causing hyponatremia. Methods: This was a retrospective study of children <18 years receiving IV SMP/TMX. Comparisons were conducted via Mann-Whitney-Wilcoxon and Mantel-Haenszel χ² tests with an a priori P value <0.05. Results: Sixty-one patients received 66 total courses; 20 courses (30.3%) were associated with hyponatremia with a decrease in the median nadir serum sodium concentration of 133 and 138 mEq/L in the hyponatremic and nonhyponatremic groups, respectively (P<0.001). The median age (interquartile range) was lower in the hyponatremic versus nonhyponatremic group, but this was not statistically significant: 0.6 (0.1-5.5) versus 3.9 (0.3-11.0) years; P=0.077. There was no significant difference in the median cumulative dose (mg/kg) between groups; P=0.104. In addition, there was a significant difference in the number of children in the hyponatremic versus nonhyponatremic groups receiving diuretics (16 [80.0%] vs 23 [50.0%], P=0.023) and other medications that cause hyponatremia (7 [35.0%] vs 5 [10.9%], P=0.034), respectively. Furosemide was noted to be the medication most associated with hyponatremia. Conclusion and Relevance: Approximately one-third administered IV SMX/TMP developed hyponatremia. Concomitant furosemide administration was one of the most common risk factors. Clinicians should be aware of this potential adverse event when initiating IV SMX/TMP in children.

A case of extreme hyponatremia without neurologic symptoms

Our case report highlights that profound hyponatremia with sodium level 101 mmol/L could have no CNS symptoms, and drugs and endocrine disorders are relatively common causes and should be considered in the differential diagnosis of hyponatremia. Standard dose trimethoprim-sulfamethoxazole-induced hyponatremia is rare but still worth close attention in clinical practice.

Incidence of Hyponatremia with High-Dose Trimethoprim-Sulfamethoxazole Exposure

BACKGROUND

Trimethoprim-sulfamethoxazole (TMP-SMX) is a commonly prescribed antibiotic used at high doses for treatment of pneumocystis pneumonia and other infections. Trimethoprim is structurally related to the potassium-sparing diuretic amiloride and has been associated with hyperkalemia and hyponatremia through blocking of epithelial sodium channels in the distal nephron. The incidence of hyponatremia in hospitalized patients treated with high-dose TMP-SMX is unknown.

METHODS

We performed a single-center retrospective chart review of all hospitalized patients who received high-dose TMP-SMX (n = 235) from January 2012 to July 2014. Patients with congestive heart failure, cirrhosis, estimated glomerular filtration rate <30 mL/min/1.73 m², baseline hyponatremia, and those on other medications associated with hyponatremia were excluded. Hyponatremia was defined as a serum sodium level <136 mEq/L.

RESULTS

Analysis was restricted to 76 unique patients who received more than 8 mg/kg/d of TMP for ≥3 days. Mean starting serum sodium at time of TMP-SMX initiation was 138.4 ± 2.1 mEq/L. Fifty-five patients (72.3%) developed hyponatremia while on therapy, of which 43.6% (n = 24) were cases of serum sodium <130 mEq/L. Mean sodium at the time of nadir was 131.6 ± 5.1 mEq/L. Hyponatremia was noted, on average, 5.5 days after initiation of therapy, with more severe hyponatremia development among African American patients. Urine sodium concentrations were available for 40.0% (22/55) of incident hyponatremia cases, with mean urinary sodium of 104.8 ± 55.9 mEq/L. Hyponatremia often resolved within 3 weeks of drug discontinuation.

CONCLUSIONS

There is a high incidence (72.3%) of hyponatremia associated with the use of high-dose TMP-SMX among hospitalized patients. This is an overlooked and potentially reversible cause of hyponatremia.

Trimethoprim-associated hyponatremia

Hyponatremia associated with diuretic use can be clinically difficult to differentiate from the syndrome of inappropriate antidiuretic hormone secretion (SIADH). We report a case of a 28-year-old man with HIV (human immunodeficiency virus) and Pneumocystis pneumonia who developed hyponatremia while receiving trimethoprim-sulfamethoxazole (TMP/SMX). Serum sodium level on admission was 135 mEq/L (with a history of hyponatremia) and decreased to 117 mEq/L by day 7 of TMP/SMX treatment. In the setting of suspected euvolemia and Pneumocystis pneumonia, he was treated initially for SIADH with fluid restriction and tolvaptan without improvement in serum sodium level. A diagnosis of hyponatremia secondary to the diuretic effect of TMP subsequently was confirmed, with clinical hypovolemia and high renin, aldosterone, and urinary sodium levels. Subsequent therapy with sodium chloride stabilized serum sodium levels in the 126- to 129-mEq/L range. After discontinuation of TMP/SMX treatment, serum sodium, renin, and aldosterone levels normalized. TMP/SMX-related hyponatremia likely is underdiagnosed and often mistaken for SIADH. It should be considered for patients on high-dose TMP/SMX treatment and can be differentiated from SIADH by clinical hypovolemia (confirmed by high renin and aldosterone levels). TMP-associated hyponatremia can be treated with sodium supplementation to offset ongoing urinary losses if the TMP/SMX therapy cannot be discontinued. In this Acid-Base and Electrolyte Teaching Case, a less common cause of hyponatremia is presented, and a stepwise approach to the diagnosis is illustrated.

Trimethoprim-sulfamethoxazole-induced hyperkalemia in a patient with normal renal function

The authors present a case of Trimethoprim-sulfamethoxazole-induced hyperkalemia in a patient with normal renal function. While toxicity of this drug has been reported in patients with renal insufficiency, this case highlights the toxicity associated with normal kidney function. Due to its popularity in the medical field and to the largely unrecognized effect of hyperkalemia, it is important to consider such adverse effects when prescribing TMX-SMX. One must be reminded of the possibility of the development of life-threatening hyperkalemia in relatively healthy patients.

Electrolyte disturbances associated with commonly prescribed medications in the intensive care unit

Electrolyte imbalances are common in critically ill patients. Although multiple disease states typically encountered in the intensive care unit may be responsible for the development of electrolyte disorders, medications may contribute to these disturbances as well. Medications can interfere with the absorption of electrolytes, alter hormonal responses affecting homeostasis, as well as directly impact organ function responsible for maintaining electrolyte balance. The focus on this review is to identify commonly prescribed medications in the intensive care unit and potential electrolyte disturbances that may occur as a result of their use. This review will also discuss the postulated mechanisms associated with these drug-induced disorders. The specific drug-induced electrolyte disorders discussed in this review involve abnormalities in sodium, potassium, calcium, phosphate, and magnesium. Clinicians encountering electrolyte disturbances should be vigilant in monitoring the patient's medications as a potential etiology. Insight into these drug-induced disorders should allow the clinician to provide optimal medical management for the critically ill patient, thus improving overall healthcare outcomes.