Adenosine triphosphate (ATP) is an adenine nucleotide containing three phosphate groups esterified to the sugar moiety. Adenosine triphosphate is the energy source in living cells. In physiological conditions, the average concentration varies from 3150 mM in mammalian cells to 1500–1900 mM in human blood cells. Extracellular adenosine and adenosine triphosphate (ATP) are involved in biological processes including neurotransmission, muscle contraction, cardiac function, platelet function, vasodilatation, signal transduction and secretion in a variety of cell types. A large family of membrane-bound receptors mediates cell signalling by ATP and adenosine. These purinergic receptors ultimately determine the variety of effects induced by extracellular ATP and adenosine. ATP and adenosine have strong negative chronotropic and dromotropic effects on the mammalian heart. The sensitivity of the sinus node and the atrioventricular node to ATP and adenosine manifests pronounced variability among species. For more than three decades, ATP has been used routinely in Europe in the acute therapy of paroxysmal supraventricular tachycardia. ATPace™, an injectable formulation of adenosine 5′-triphosphate (ATP), was developed by Cordex Pharma, Inc. (Cordex) as a diagnostic and therapeutic drug for the management of cardiac bradyarrhythmias. Extracellular ATP exerts multiple effects in various cell types by activating cell-surface receptors known as P2 receptors. In the heart, ATP suppresses the automaticity of cardiac pacemakers and atrioventricular (AV) nodal conduction via adenosine, the product of its degradation by ecto-enzymes, as well as by triggering a cardio-cardiac vagal reflex. ATP, given as a rapid intravenous bolus injection, has been used since the late 1940s as a highly effective and safe therapeutic agent for the acute termination of reentrant paroxysmal supraventricular tachycardia (PSVT) involving the AV node. In addition, preliminary studies have shown that ATP can also be used as a diagnostic agent for the identification of several cardiac disorders including sinus node dysfunction (sick sinus syndrome), dual AV nodal pathways, long QT syndrome, and bradycardic syncope. The US Food and Drug Administration has approved Cordex formulation for ATP as an Investigational New Drug and two pathways for its marketing approval; one therapeutic, i.e., acute termination of paroxysmal PSVT, and the other diagnostic, i.e., the identification of patients with bradycardic syncope who can benefit from pacemaker therapy. However later ATPace development for the treatment of bradycardia and paroxysmal supraventricular tachycardia was discontinued.

Tylosin (trade names Tylocine, Tylan) is a bacteriostat feed additive used in veterinary medicine. It has a broad spectrum of activity against Gram-positive organisms and a limited range of Gram-negative organisms. It is found naturally as a fermentation product of Streptomyces fradiae. It is a macrolide antibiotic. Tylosin is used in veterinary medicine to treat bacterial infections in a wide range of species and has a high margin of safety. Tylosin is certified by the FDA but is only approved for use in livestock such as cattle, chickens, swine, and turkeys. The FDA has prohibited the use of tylosin in dogs and cats, except where it is specifically prescribed by a veterinarian. Tylosin has a bacteriostatic effect on susceptible organisms, caused by inhibition of protein synthesis through binding to the 50S subunit of the bacterial ribosome.

Farnesol, (2E,6E)- is an isoprenoid found in many aromatic plants and is also produced in humans, where it acts on numerous nuclear receptors and has received considerable attention due to its apparent anticancer properties. Farnesol is present in many essential oils such as citronella, neroli, cyclamen, lemon grass, tuberose, rose, musk, balsam, and tolu. It is used in perfumery to emphasize the odors of sweet floral perfumes. Its method of action for enhancing perfume scent is as a co-solvent that regulates the volatility of the odorants. It is especially used in lilac perfumes. Farnesol is a natural pesticide for mites and is a pheromone for several other insects. In a 1994 report released by five top cigarette companies, farnesol was listed as one of 599 additives to cigarettes. Farnesol has been suggested to function as a chemopreventative and anti-tumor agent. Farnesol is subject to restrictions on its use in perfumery as some people may become sensitized to it, however, the evidence that farnesol can cause an allergic reaction in humans is disputed.