Acetylleucine is a drug that is used for symptomatic treatment of acute vestibular vertigo and dizziness. Its pharmacodynamics are not fully understood. The hypothesis is that it restores the membrane potential, via an interaction with membrane phospholipids on the injured side of vestibular neurons mainly in the thalamus or parietal region of the cortex. Clinical trials on animals showed an improvement in locomotor balance after forced rotation or unilateral vestibular neurotomy. Acetylleucine has a marketing authorisation in France although there is no evidence of its efficacy on human. Acetylleucine neither reduced the nausea associated with this provocative stimulus, nor hastened the acquisition or retention of vestibular habituation of motion sickness and nystagmus.

Ergosterol was discovered over 100 years ago in the plant pathogenic ergot fungus Claviceps purpurea. Ergosterol is the major fungal membrane sterol that regulates membrane fluidity, plasma membrane biogenesis and function. Antifungal drugs such as Amphotericin B exerts its action by simply binding ergosterol. Vitamin D2 (ergocalciferol) is derived from ergosterol by UVB irradiation. Ergocalciferol is used for treating low parathyroid hormone levels, rickets (a vitamin D deficiency condition), and low phosphate levels in the body.

Indium sulfate (In2(SO4)3) is a grayish-white powder. It is hydroscopic and has a monoclinic crystal structure. Indium sulfate is being marketed as the newest miracle dietary supplement and is falsely advertised as a dietary aid as an enhancer of food and mineral absorption, an anti-aging supplement, a blood pressure lowering supplement. There is no scientific support for claims that indium has beneficial effects. Indium sulfate can cause the accumulation of indium in the kidney, oxidative damage, pathological changes and dysfunction in the kidney of rats.

Thallium is a soft, silvery-white metal that tarnishes easily. Most thallium is used by the electronics industry in photoelectric cells. Thallium oxide is used to produce special glass with a high index of refraction, and also low melting glass that becomes fluid at about 125K. An alloy of mercury containing 8% thallium has a melting point 20°C lower than mercury alone. This can be used in low temperature thermometers and switches. Thallium is more toxic to humans than mercury, cadmium, lead, copper or zinc and has been responsible for many accidental, occupational, deliberate, and therapeutic poisonings since its discovery in 1861. Its chemical behavior resembles the heavy metals (lead, gold and silver) on the one hand and the alkali metals (K, Rb, Cs) on the other. It occurs almost exclusively in natural waters as monovalent thallous cation. The solubility of thallous compounds is relatively high so that monovalent thallium is readily transported through aqueous routes into the environment. Thallium can be transferred from soils to crops readily and accrues in food crops. The fascinating chemistry and high toxicity potential make thallium and its compounds of particular scientific interest and environmental concern. Radioactive isotope thallium-201 is a radiopharmaceutical used in myocardial perfusion imaging (MPI) using either planar or single photon emission computed tomography (SPECT) techniques for the diagnosis and localization of myocardial infarction. Thallium-201 may also have prognostic value regarding survival, when used in the clinically stable patient following the onset of symptoms of an acute myocardial infarction, to assess the site and size of the perfusion defect. Additionally, Thallium-201 may be used in conjunction with exercise stress testing as an adjunct in the diagnosis of ischemic heart disease (atherosclerotic coronary artery disease) and is also indicated for the localization of sites of parathyroid hyperactivity in patients with elevated serum calcium and parathyroid hormone levels.

Rubidium Rb-82 is a radioactive drug is indicated for Positron Emission Tomography (PET) imaging of the myocardium under rest or pharmacologic stress conditions to evaluate regional myocardial perfusion in adult patients with suspected or existing coronary artery disease. Rb-82 is analogous to potassium ion (K+) in its biochemical behavior and is rapidly extracted by the myocardium proportional to the blood flow. Rb+ participates in the sodium-potassium (Na+/K+) ion exchange pumps that are present in cell membranes. The intracellular uptake of Rb-82 requires maintenance of ionic gradient across cell membranes. Rb-82 radioactivity is increased in viable myocardium reflecting intracellular retention, while the tracer is cleared rapidly from necrotic or infarcted tissue. Rubidium Rb-82, a nonreactor produced tracer, is believed to have superior accuracy compared to Tc-99m and Tl-201 SPECT, with 5-20 times lower radiation dose. Specific drug-drug interactions have not been studied. Unintended radiation exposure has occurred in some patients who received rubidium Rb-82 chloride injections at clinical sites where generator eluate testing appeared insufficient.

Neridronic acid (6-amino-1-idroxyesilidene-1,1-bisphosphonate) is a nitrogen-containing bisphosphonate licensed in Italy for the treatment of osteogenesis imperfecta and Paget’s disease of bone. The pharmacodynamic profile is similar to that of other nitrogen-containing bisphosphonates and is characterized by its high affinity for bone tissue particularly at sites undergoing a process of remodeling. In growing children affected by osteogenesis imperfect, neridronic acid rapidly increases bone mineral density as measured by dual X-ray absorptiometry and this is associated with a significant decrease in fracture cumulative number. Similar results have been obtained also in newborns (<12-month-old) and in adult patients. In Paget’s disease of bone, 200 mg intravenous neridronic acid is associated with a 65% rate of full remission and a biochemical response (decrease of > 75% of bone turnover markers) in 95% of the patients. Neridronic acid treatment has been reported to be effective also in other skeletal diseases such as osteoporosis, algodystrophy, hypercalcemia of malignancy and bone metastasis. Neridronic acid has been developed only for parenteral use, and it is the only one used as the intramuscular injection. This avoids all the limitations of oral bisphosphonates and may be offered for a home treatment with simple nursing assistants

Incadronate (Disodium Cycloheptylaminomethylene diphosphate) is used to treat malignancy-associated hypercalcemia (MAH) in Japan. Experiments on rodents have revealed that this drug could be an effective agent for the treatment of various arthritic conditions, including human rheumatoid arthritis. In addition was shown, that incadronate induced growth inhibition and apoptotic death of pancreatic cancer cells. Incadronate also inhibited migration presumably by preventing the activation of Rho by lysophosphatidic acid. Thus, this drug can be of value in regimens for the treatment of pancreatic cancer.

Isaxonine (N-isopropyl-amino-2-pyrimidine orthophosphate) is able to accelerate nerve regeneration and functional recovery. Isaxonine has specific affinity for peripheral nerves. It acts directly on the neuron or indirectly by stimulating the production of a growth factor remains unknown. It demonstrates activity in the treatment of neuropathies of various etiology. Isaxonine treatment may be associated with hepatotoxicity.

Osmium is a shiny, silver metal that resists corrosion. It is the densest of all the elements and is twice as dense as lead. Osmium has only a few uses. It is used to produce very hard alloys for fountain pen tips, instrument pivots, needles and electrical contacts. It is also used in the chemical industry as a catalyst. Osmium has no known biological role. The metal is not toxic, but its oxide is volatile and very toxic, causing lung, skin and eye damage. Osmium compounds are attracting increasing attention as potential anticancer drugs. Osmium complexes are considered interesting alternatives to ruthenium-based anticancer agents because of their relative inertness and sufficient stability under physiological conditions.