A Systematic Critical Review of Clinical Pharmacokinetics of Torasemide.

PURPOSE: Torasemide is a potassium-sparing loop diuretic used to treat fluid retention associated with congestive heart failure and kidney and hepatic diseases. This systematic review was conducted to combine all accessible data on the pharmacokinetics (PK) of torasemide in healthy and diseased populations, which may help clinicians avert adverse drug reactions and determine the correct dosage regimen. METHODS: Four databases were systematically searched to screen for studies associated with the PK of torasemide, and 21 studies met the eligibility criteria. The review protocol was registered in the PROSPERO database (CRD42023390178). RESULTS: A decrease in maximum plasma concentration (C max ) was observed for torasemide after administration of the prolonged-release formulation in comparison to that after administration of the immediate-release formulation, that is, 1.12 ± 0.17 versus 1.6 ± 0.2 mcg/mL. After administering an oral dose of torasemide, a 2-fold increase in the area under the concentration-time curve (AUC) was reported in patients with congestive heart failure compared with the healthy population. Moreover, the patients with renal failure (clearance < 30 mL/min) showed an increase in value of AUC 0-∞ that is, 42.9 versus 8.091 mcg.h -1 .mL -1 compared with healthy subjects. In addition, some studies have reported interactions with different drugs, in which irbesartan showed a slight increase in the AUC 0-∞ of torasemide, whereas losartan and empagliflozin did not. CONCLUSIONS: The current review summarizes all available PK parameters of torasemide that may be beneficial for avoiding drug-drug interactions in subjects with renal and hepatic dysfunction and for predicting doses in patients with different diseases.

Rationale and Design of the Genotype-Blinded Trial of Torasemide for the Treatment of Hypertension (BHF UMOD).

BACKGROUND: Genome-wide association studies have identified single nucleotide polymorphisms (SNPs) near the uromodulin gene (UMOD) affecting uromodulin excretion and blood pressure (BP). Uromodulin is almost exclusively expressed in the thick ascending limb (TAL) of the loop of Henle and its effect on BP appears to be mediated via the TAL sodium transporter, NKCC2. Loop-diuretics block NKCC2 but are not commonly used in hypertension management. Volume overload is one of the primary drivers for uncontrolled hypertension, so targeting loop-diuretics to individuals who are more likely to respond to this drug class, using the UMOD genotype, could be an efficient precision medicine strategy. METHODS: The BHF UMOD Trial is a genotype-blinded, multicenter trial comparing BP response to torasemide between individuals possessing the AA genotype of the SNP rs13333226 and those possessing the G allele. 240 participants (≥18 years) with uncontrolled BP, on ≥1 antihypertensive agent for ≥3 months, will receive treatment with Torasemide, 5 mg daily for 16 weeks. Uncontrolled BP is average home systolic BP (SBP) >135 mmHg and/or diastolic BP >85 mmHg. The primary outcome is the change in 24-hour ambulatory SBP area under the curve between baseline and end of treatment. Sample size was calculated to detect a 4 mmHg difference between groups at 90% power. Approval by West of Scotland Research Ethics Committee 5 (16/WS/0160). RESULTS: The study should conclude August 2021. CONCLUSIONS: If our hypothesis is confirmed, a genotype-based treatment strategy for loop diuretics would help reduce the burden of uncontrolled hypertension. CLINICAL TRIALS REGISTRATION: https://clinicaltrials.gov/ct2/show/NCT03354897.