Hyponatremia Associated with Prophylactic Low-Dose Trimethoprim during Systemic Corticosteroid Therapy for AQP4-Positive Optic Neuritis in a Diabetic Patient

Severe hyponatremia due to trimethoprim-sulfamethoxazole-induced SIADH

Hyponatremia, a serum sodium level of <135 mEq/L, is the most common electrolyte abnormality occurring in 5%–35% of hospitalized patients. It is a predictor of increased morbidity and mortality. Diuretics, psychotropic, and antiepileptic drugs are commonly implicated in drug-induced hyponatremia. Trimethoprim-sulfamethoxazole and spironolactone are two commonly prescribed drugs; unfortunately, most providers are unfamiliar with these two drugs causing hyponatremia. Simultaneous use of trimethoprim-sulfamethoxazole and spironolactone can cause serious drug interactions that increase the risk of hyponatremia, hyperkalemia, and overall mortality. Despite recommendations to avoid using these two drugs concurrently, many healthcare providers continue to prescribe them together. We report a case of an elderly female with severe hyponatremia caused by trimethoprim-sulfamethoxazole superimposed on a chronic but stable mild hyponatremia.

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.

Comparison of combination therapy of prednisolone and cyclosporine with corticosteroid pulse therapy in Vogt-Koyanagi-Harada disease

PURPOSE

To compare the efficacy and safety of a combination therapy of prednisolone and cyclosporine and corticosteroid pulse therapy in Vogt-Koyanagi-Harada (VKH) disease.

STUDY DESIGN

A prospective, multicenter, randomized, non-inferiority trial.

METHODS

Patients of new-onset acute VKH disease at 11 centers in Japan between 2014 and 2018 were randomized to a combination (oral prednisolone 60 mg daily with gradual taper-off to 35 mg/day and cyclosporine 3 mg/kg/day) and corticosteroid (methylprednisolone 1000 mg for 3 days followed by oral prednisolone) groups, and were followed for 1 year.

RESULTS

Thirty-four were assigned to the combination and thirty-six patients to the corticosteroid group. Recurrence/worsening risk was 0.15 (95% confidence-interval [CI] 0.03-0.27) in the combination group and 0.25 (95% CI 0.11-0.39) in the corticosteroid group, with a risk difference of - 0.10 (90% CI - 0.27 to 0.06), demonstrating non-inferiority of the combination group with a non-inferiority margin of 0.20 (P = 0.0013). Serious adverse events occurred in three patients (two with hyponatremia and one with severe headaches) in the combination group and none in the corticosteroid group. Sunset glow fundus grades and cataract rates at 1 year were 0.57 (95% CI 0.42-71) and 4.3% in the combination group and 0.91 (95% CI 0.78-1.04) and 34.0% in the corticosteroid group, respectively.

CONCLUSIONS

Combination therapy was noninferior to corticosteroid therapy with respect to recurrence/worsening risk. Notably, the recurrence/worsening risk, sunset glow fundus grade, and cataract rate were lower in the combination group than in the corticosteroid group.