Caffeine is a methylxanthine alkaloid found in the seeds, nuts, or leaves of a number of plants native to South America and East Asia that is structurally related to adenosine and acts primarily as an adenosine receptor antagonist with psychotropic and anti-inflammatory activities. Upon ingestion, caffeine binds to adenosine receptors in the central nervous system (CNS), which inhibits adenosine binding. This inhibits the adenosine-mediated downregulation of CNS activity; thus, stimulating the activity of the medullary, vagal, vasomotor, and respiratory centers in the brain. The anti-inflammatory effects of caffeine are due the nonselective competitive inhibition of phosphodiesterases. Caffeine is used by mouth or rectally in combination with painkillers (such as aspirin and acetaminophen) and a chemical called ergotamine for treating migraineheadaches. It is also used with painkillers for simple headaches and preventing and treating headaches after epidural anesthesia. Caffeine creams are applied to the skin to reduce redness and itching in dermatitis. Healthcare providers sometimes give caffeine intravenously (by IV) for headache after epidural anesthesia, breathing problems in newborns, and to increase urine flow. In foods, caffeine is used as an ingredient in soft drinks, energy drinks, and other beverages.

Iomeprol is a nonionic, monomeric iodinated contrast medium. Iomeprol helps optimize images obtained with sophisticated multidetector computed tomography (MDCT) technology, especially for neurological, brain, liver, cardiac and vascular scanning. The mechanism of action of Iomeprol is as a X-Ray Contrast Activity. Launched by the Bracco Group in 1995, Iomeprol (Iomeron) currently is registered in more than 40 countries worldwide, including all major European markets, Japan, and major Middle East and Asian Pacific countries.

Macimorelin (AEZS 130) is an orally active, small-molecule, peptidomimetic growth hormone secretagogue receptor (GHSR1A) agonist (ghrelin analogue), being developed by AEterna Zentaris for the diagnosis of adult growth hormone deficiency (AGHD; somatotropin deficiency), and for the treatment of cachexia associated with chronic disease such as AIDS and cancer. Macimorelin was approved by the FDA in December 2017 under the market name Macrilen for oral solution. Macimorelin stimulates GH release by activating growth hormone secretagogue receptors present in the pituitary and hypothalamus. Macimorelin has been granted orphan drug designation by the FDA for diagnosis of AGHD.

Technetium Tc 99m apcitide is a radiopharmaceutical containing a metastable nuclear isomer of technetium-99. Upon radioactive decay with a half-life of 6 hours gamma-rays which can be detected using conventional equipment for X-ray diagnostics. Tc 99m contains the small-molecule synthetic peptide apcitide which binds to the PIIb/IIIa receptors on the surface of activated platelets, which are a major component in active thrombus formation. The localization of radioactivity may be recorded by gamma-ray detection camera. Tc 99m apcitide is indicated for scintigraphic imaging of acute venous thrombosis in the lower extremities in patients with signs and symptoms of acute blood clots. It is marketed by Bayer under tradename AcuTect.

Mangafodipir (sold under the brand name Teslascan as mangafodipir trisodium) is a contrast agent delivered intravenously to enhance contrast in magnetic resonance imaging (MRI) of the liver. Mangafodipir is a manganese (Mn2+) chelate with the ligand fodipir (dipyridoxyl diphosphate or DPDP). Mangafodipir trisodium is metabolised (dephosphorylated) and partially transmetallated (manganese exchanged for zinc) after intravenous administration. Manganese that is released from mangafodipir is taken up by hepatocytes thereby increasing the SI of normal liver tissue. This may result in an improvement of the detection of liver metastases, which usually have no hepatocytes. The metabolites of fodipir are renally excreted, whilst the biliary route mainly excretes manganese. Mangafodipir was withdrawn from the US market in 2003 and the European market in 2012.

Ioxilan is a nonionic X-ray contrast agent approved by the United States Food and Drug Administration for X-ray imaging contrast enhancement. Ioxilan can be administered intravenously for excretory urography and contrast-enhanced computed tomography (CT) imaging of the head and body. Ioxilan can also be given intraarterially for cerebral arteriograpy, coronary arteriography and left ventriculography, visceral angiography, aortography, and peripheral arteriography.

Iobenguane I-131 is a radioactive therapeutic agent. The drug contains radioactive isotope I-131, which decays by electron emission with a half-life of about 8 days. By the chemical structure, iobenguane is similar to the neurotransmitter norepinephrine and is subject to the same uptake and regulation pathways. After intravenous administration, iobenguane I-131 accumulates within pheochromocytoma and paraganglioma cells, and radiation from the radioactive decay causes cell death and tumor necrosis. Iobenguane I-131 was approved by the FDA for the treatment of adult and pediatric patients with iobenguane scan positive, unresectable, locally advanced or metastatic pheochromocytoma or paraganglioma who require systemic anticancer therapy. Iobenguane I-131 is investigated in clinical trials as a treatment of neuroblastoma, ganglioneuroblastoma and other tumors of neuroendocrinal origin.

Perflubron is a contrast agent used for signal enhancement during the indicated ultrasound imaging procedures. Perflubron is a constituent of blood substitute, indicated for liquid breathing.

Iotrol, a nonionic dimeric, intrathecal contrast medium for myelography. This agent does not exhibit any cytotoxic effect on human healthy nucleus pulposus (NP) cells.