# Using Specific Steroid Molecules to Block Salt Retention in the Body > A 1976 medical patent describing the use of 11-beta,18-oxidopregnane compounds to help the body excrete sodium by blocking the salt-retaining effects of the hormone aldosterone. - **Patent:** US 4081538 - **Original title:** Aldosterone antagonists - **Owner:** Individual - **Granted:** 1978 - **Status:** Public domain (expired) - **Times cited:** 5 - **Field:** pharmaceutical, biotech ## What it does This patent details a method for treating patients who retain too much salt by administering specific chemical compounds known as 11-beta,18-oxidopregnanes. These molecules act as aldosterone antagonists, meaning they compete with or block the natural hormone aldosterone, which normally signals the kidneys to hold onto sodium. By inhibiting this hormone, the drug forces the kidneys to excrete more sodium, which can help lower blood pressure or reduce fluid buildup. The claims specify a range of chemical structures, including 18-deoxyaldosterone, that can be used to achieve this effect. ## What it does NOT cover - Does not cover the use of spironolactone or other non-oxidopregnane class diuretics. - Does not cover treatments for conditions unrelated to mineralocorticoid-induced sodium retention. - Does not claim the synthesis process for creating these specific chemical compounds. ## The clever bit The invention identifies that by modifying the 11-beta,18-oxido structure of the pregnane backbone, one can create a molecule that binds to the aldosterone receptor without triggering the same salt-retaining response as the hormone itself. ## Real-world examples 1. Experimental diuretic therapies 2. Research into mineralocorticoid receptor antagonists ## Why it matters This patent represents an early effort to pharmacologically manage fluid balance by targeting the mineralocorticoid pathway. While aldosterone antagonists are now a standard class of drugs for heart failure and hypertension, this patent highlights the foundational exploration of steroid-based molecules to modulate kidney function. ## Frequently asked questions ### What does Using Specific Steroid Molecules to Block Salt Retention in the Body cover? A 1976 medical patent describing the use of 11-beta,18-oxidopregnane compounds to help the body excrete sodium by blocking the salt-retaining effects of the hormone aldosterone. ### Who owns patent US 4081538? Individual owns this patent, granted in 1978. ### When does this patent expire? This patent has expired and is now in the public domain — anyone can use the invention freely. ### What is patent US 4081538 cited by? This patent has been cited by 5 later patents that build on its ideas. ### What problem does this patent solve? This patent represents an early effort to pharmacologically manage fluid balance by targeting the mineralocorticoid pathway. While aldosterone antagonists are now a standard class of drugs for heart failure and hypertension, this patent highlights the foundational exploration of steroid-based molecules to modulate kidney function. ### What does this patent NOT cover? Does not cover the use of spironolactone or other non-oxidopregnane class diuretics. **Full plain-English explainer:** https://patentbrief.org/patent/us/4081538/aldosterone-antagonists **Original patent:** https://patents.google.com/patent/US4081538 --- _Source: PatentBrief — https://patentbrief.org. 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