Something strange kept showing up in the slide shows at a significant cardiovascular conference in São Paulo, Brazil, in 1984. Photographs of a snake, the Brazilian pit viper, Bothrops jararaca, with its characteristic zigzag markings and tongue that appeared to be made for maximum alarm, were repeatedly displayed by researchers between the graphs and the clinical data. The pictures weren’t ornamental. They were the story of origin.
Captopril, the medication under discussion, was derived from a peptide present in the venom of that snake, and the researchers presenting it seemed unable to help but remind their audience of the improbable route that had led them to this point. According to legend, some of them even planned a visit to a nearby snake farm so conference attendees could get a close-up look at the animal. The scientists’ proud presentation of the animal whose bite had effectively given them a new class of medicine has an almost theatrical quality.
Snake Venom & Heart Medicine — Key Drugs, Science & History
| The Founding Discovery | Captopril — the first ACE inhibitor, derived from bradykinin-potentiating peptides (BPPs) found in the venom of the Brazilian pit viper Bothrops jararaca; FDA-approved in 1981 for hypertension and diabetic nephropathy; fundamentally changed how physicians treat high blood pressure |
| The Snake Behind Captopril | Bothrops jararaca — Brazilian pit viper, native to South America; characterized by striking zig-zag markings; its venom causes dramatic blood pressure drops in bite victims, which first alerted researchers to its cardiovascular potential |
| Other Approved Venom Drugs | Eptifibatide (from Sistrurus miliarius barbouri — pygmy rattlesnake) and Tirofiban (from Echis carinatus — saw-scaled viper) — both FDA-approved in 1998 for acute coronary syndrome; prevent platelet aggregation and blood clots during heart attacks |
| Ischemic Heart Disease Scale | Ischemic heart disease (IHD) is the leading cause of death worldwide, accounting for 16% of total global disease burden; includes heart attacks, unstable angina, and sudden cardiac death |
| How Venom Works in the Body | Snake venom proteins and peptides — comprising 90–95% of venom dry weight — target specific receptors, ion channels, and enzymes in the cardiovascular system; effects include blood pressure changes, coagulation disruption, and tissue-level cardiac protection |
| Key Molecule Classes | Bradykinin-Potentiating Peptides (BPPs), Natriuretic Peptides (NPs), Disintegrins, Three-Finger Toxins (3FTx), Phospholipases A2 (PLA2s), fibrinolytic enzymes — each targeting different aspects of cardiovascular function |
| Stroke Application | Defibrase — derived from Bothrops moojeni venom; approved in China (2006) for stroke and ischemic attack treatment; approved in Japan for sudden deafness; converts plasminogen into plasmin to dissolve dangerous blood clots |
| Pain Application | Cobratide — derived from Naja naja atra (Chinese cobra); approved in China in 1978 for moderate to severe chronic pain; blocks nicotinic acetylcholine receptors to interrupt pain signaling |
| Next Frontier: AI + Venom | Nature Reviews Chemistry and recent research highlight deep learning and AI as tools for mining venom toxin libraries across 130+ snake species — dramatically accelerating discovery of new cardiovascular drug candidates from venom compounds |
| Key Research Bodies | PubMed Central (NIH), ScienceDirect, ResearchGate — ongoing clinical and preclinical studies on venom-derived compounds for IHD, atherosclerosis, hypertension, cancer, and diabetes treatment |
| Conservation Concern | Climate change is threatening wild snake populations globally — raising concerns that the biological library these species represent, including undiscovered medicinal compounds, could be lost before it is fully explored |
When the FDA approved captopril in 1981 for the treatment of hypertension and diabetic nephropathy, it became the first ACE inhibitor and significantly altered cardiovascular care. Bradykinin-potentiating peptides, which cause a sharp drop in blood pressure in bite victims, were the mechanism it mimicked and had been present in Bothrops jararaca’s venom for decades before anyone considered the possibility of using the same mechanism therapeutically. Tens of millions of people worldwide have been prescribed the medication that was created after researchers asked that question and received a reasonably prompt response. A deadly drug that, with the correct molecular translation, became something that prolonged heartbeats is one of the more subtly amazing tales in contemporary pharmacology.
Captopril was not the end of the venom-to-drug pipeline. In 1998, the FDA approved eptifibatide and tirofiban, two additional compounds derived from snakes, to treat acute coronary syndrome, which includes heart attacks. Both function by keeping platelets from aggregating and creating the blood clots that obstruct coronary arteries.
The venom of the pygmy rattlesnake, Sistrurus miliarius barbouri, a diminutive and unassuming snake indigenous to the American Southeast, is the source of eptifibatide. The saw-scaled viper Echis carinatus, which is found throughout the Middle East and South Asia, is the ancestor of tirofiban. It is one of the snakes that kills more people from snakebite than nearly any other species on the planet. It’s difficult to overlook the irony of that specific lineage. The molecular template for a medication that saves lives by precisely controlling coagulation disruption came from the snake that kills people by doing so.
This is the fundamental paradox of venom medicine, and it is better to sit with it than to ignore it. Evolution created snake venom with the ability to cause harm, including tissue breakdown, blood flow disruption, paralysis, and death. It is pharmacologically intriguing due to the same characteristics that make it deadly. selectivity. Strength. the capacity to precisely target very specific receptors or enzymes. Proteins and peptides make up 90 to 95 percent of the dry weight of snake venom, and these molecules have undergone millions of years of evolutionary pressure to become incredibly skilled at what they do. In essence, what happens if we take that precision and reroute it toward healing rather than harm is what drug developers, working in the opposite direction, are asking.
According to the state of the research, the answer could be quite a bit. Researchers are currently studying venom compounds from over 130 species of snakes in the Viperidae, Crotalidae, and Elapidae families—more than 130 species have been cataloged in recent analyses—in an effort to find compounds with potential uses in chronic pain, diabetes, cancer, cardiovascular disease, and stroke. Since 1978, cobratide—derived from the Chinese cobra—has been used in China to treat moderate to severe pain. It blocks nicotinic acetylcholine receptors with a specificity that has proven difficult for synthetic substances to match.
Defibrase, which is derived from another species of Brazilian pit viper, has been approved in China for the treatment of stroke. It does this by breaking up clots that prevent blood flow to the brain by converting plasminogen into plasmin. These are approved medications that are currently being used in clinical settings, but most people outside of specialized medical circles are unaware of them. They are not experimental curiosities.
The role artificial intelligence is beginning to play in this field is truly novel. In order to quickly screen molecular structures for therapeutic signatures that would take years for human researchers to manually identify, deep learning models are currently being applied to venom toxin libraries. It’s possible that the most significant venom-derived cardiovascular medication hasn’t been found yet; it might be waiting for a researcher with the necessary equipment to locate it in the venom gland of a species that is still being cataloged in Central Africa or Southeast Asia.
Even though that possibility is still theoretical, it becomes less so as computational tools advance. As this field develops, it seems possible that the story of captopril in 1981 will be remembered as the beginning of something much bigger rather than as its conclusion. It all started at the snake farm in São Paulo, where the delegates from the 1984 conference went to see the pit viper. The researchers are currently analyzing hundreds of venom proteomes using machine learning models to determine the next steps.
