Tribromoethanol is a popular injectable anesthetic agent commonly used for embryo-transfer surgery for the generation of transgenic mice and sometimes rats. In humans and animals, Tribromoethanol produces a generalized CNS depression, including both the respiratory and cardiovascular centers. It undergoes conjugation with glucuronic acid during metabolism in the liver, followed by excretion in the urine as TBE glucuronate. Tribromoethanol causes rapid and deep anesthesia followed by rapid and full postoperative recovery, but the margin of safety between anesthetic and the lethal dose is narrow. Depression of respiration and circulation, together with its general unpredictability, eventually discouraged its use. Although Tribromoethanol solutions are often referred to as Avertin, this is a misnomer. Avertin was the trade name for Winthrop Laboratories’ proprietary Tribromoethanol formulation, which is no longer available. Marketing of pharmaceutical-grade Tribromoethanol took place under several proprietary names, including Avertin, Bromethol, Ethobrom, and Narkolan, each as a 66.7% (w/w) solution of Tribromoethanol in tertiary-amyl alcohol, wherein each milliliter contained 1 g of Tribromoethanol. Although pharmaceutical-grade TBE has not been commercially available or routinely used for human or veterinary anesthesia for several years, the agent has received widespread acceptance for use in the various manipulations required for the production of genetically engineered mice and rats. Tribromoethanol is an attractive anesthetic choice for many researchers because it is easy and inexpensive to make in the laboratory from readily available reagents, requires no special equipment for its administration, and is not subject to federal or state drug enforcement agency storage or accountability regulations. More importantly, the i.p. injection of TBE results in the simple and rapid induction of short-term surgical anesthesia sufficient for the vasectomy, embryo transfer, and tail amputation for Southern blot analysis—all necessary elements in the production of genetically engineered animals.

AMG-517, a potent and selective vanilloid receptor (VR1) antagonist, was in clinical trials with Amgen for the treatment of pain. AMG 517 inhibits CAP- (500 nM), acid- (pH 5.0), or heat-(45 °C) induced 45Ca2+ influx into human TRPV1-expressing CHO Cells with IC50 of 0.76 nM, 0.62 nM and 1.3 nM. AMG-517 blocks capsaicin-, proton-, and heat-induced inward currents in TRPV1-expressing cells similarly. AMG-517 inhibits native TRPV1 activation by capsaicin in rat dorsal root ganglion neurons with an IC50 value of 0.68 nM. Oral administration of AMG-517 produces a dose-dependent increase in plasma concentrations, it also produces a dose-dependent decrease in the number of flinches induced by capsaicin treatment. The minimally effective dose (MED), based on a statistically significant difference in number of flinches from the vehicle versus capsaicin-administered group, is 0.3 mg/kg for AMG 517. The corresponding plasma concentrations are 90 to 100 ng/mL for AMG-517. AMG-517 (3 mg/kg) exhibits significant reductions in capsaicin-induced flinch up to 24 h after dosing. AMG 517 blocks thermal hyperalgesia in CFA model of pain. Unfortunately, clinical studies of AMG-517 were discontinued due to the hyperthermia observed after exposure to single and multiple doses.

Didiavalo (premethadone) is a methadone analog and precursor. Didiavalo possesses analgetic properties with the effective dose in rats 30 times higher than the analgesic dose of morphine.

Epipregnanolone is an epimer of endogenous neurosteroid pregnanolone, it has been shown to antagonize GABAA and NMDA receptors. In addition epipregnanolone inhibits calcium T-currents and stimulates TRPM3 channel. Epipregnanolone displays anesthetic properties. Epipregnanolone has been shown to reduce alcohol self-administration in rats.

Geraniol is a dietary monoterpene alcohol that is found in the essential oils of aromatic plants. To date, experimental evidence supports the therapeutic or preventive effects of geraniol on different types of cancer, such as breast, lung, colon, prostate, pancreatic, and hepatic cancer, and has revealed the mechanistic basis for its pharmacological actions. In addition, geraniol sensitizes tumor cells to commonly used chemotherapy agents. Geraniol controls a variety of signaling molecules and pathways that represent tumor hallmarks; these actions of geraniol constrain the ability of tumor cells to acquire adaptive resistance against anticancer drugs. It has been shown that geraniol inhibits HMG-CoA reductase in most types of tumor cells, which raises the possibility that the reduced prenylation of small G-proteins, such as Ras or RhoA, accounts for the antitumor effects of geraniol. In addition to its use in various commercial products, including cosmetics and fine fragrances, geraniol exerts a broad spectrum of pharmacological activities, such as anti-microbial, anti-inflammatory, anti-oxidant, anti-ulcer and neuroprotective activities. Geraniol is classified into the generally recognized-as-safe (GRAS) category by the Flavor and Extract Manufacturers Association (FEMA) and the Food and Drug Administration (FDA) of the United States.

Betadex is a nonreducing cyclic compound composed of seven alpha-(1-4) linked D-glucopyranosyl units. It is a pharmacologically inactive substance. Betadex is useful for stabilizing, solubilizing or delivering intermediate size molecules. Cyclodextrins are cyclic oligosaccharides that have been used to modulate the composition of cholesterol and other lipids in biological membranes and have also been used as pharmaceutical excipients in the formulation of hydrophobic drugs. More recently, 2-Hydroxypropyl-β-cyclodextrins (HPβCDs) have gained attention as a potential therapeutic intervention for Niemann-Pick Disease Type C1 (NPC1) disease. HPβCDs are complex mixtures of different species, and variations in production may lead to differences in composition. 2-Hydroxypropyl-β-cyclodextrin dose-dependent effects against dysfunctional intracellular cholesterol trafficking in NPC1 cells.

Oliceridine (TRV-130) is a potent μ-opioid receptor agonist. In cell-based assays, TRV130 elicits robust G protein signaling, with potency and efficacy similar to morphine, but with far less β-arrestin recruitment and receptor internalization. In rodents, TRV130 is potently analgesic while causing less gastrointestinal dysfunction and respiratory suppression than morphine at equianalgesic doses. Oliceridine is being developed by Trevena for the first-line treatment of moderate-to-severe acute postoperative pain. Phase III development is underway for the treatment of postoperative pain in the US. Phase II development is underway for the treatment of acute pain in the US.

Levobupivacaine (CHIROCAINE®) is a (S)-enantiomer of bupivacaine and it is related chemically and pharmacologically to the amino amide class of local anesthetics. Local anesthetics block the generation and the conduction of nerve impulses by increasing the threshold for electrical excitation in the nerve, by slowing propagation of the nerve impulse, and by reducing the rate of rise of the action potential. In general, the progression of anesthesia is related to the diameter, myelination, and conduction velocity of affected nerve fibers. Clinically, the order of loss of nerve function is as follows: 1) pain, 2) temperature, 3) touch, 4) proprioception and 5) skeletal muscle tone. Levobupivacaine (CHIROCAINE®) is a safer alternative for regional anesthesia than bupivacaine. It demonstrated less affinity and strength of depressant effects onto myocardial and central nervous vital centers in pharmacodynamic studies, and a superior pharmacokinetic profile.

Pipecuronium is a piperazinyl androstane derivative, which is a non-depolarizing neuromuscular blocking agent, which was approved under brand name arduan for injection. It is a long-acting neuromuscular blocking agent, indicated as an adjunct to general anesthesia, to provide skeletal muscle relaxation during surgery. Arduan can also be used to provide skeletal muscle relaxation for endotracheal intubation. Pipecuronium undergoes very little metabolism and is excreted by the kidney and the liver. Owing to its relatively long duration of action and to the residual postoperative neuromuscular block (RPONB), the use of pipecuronium was discontinued in the United States and in several European countries. Because of its excellent safety profile, the use of pipecuronium has been maintained in several countries including China, Russia, Brazil, and Hungary, among others. Its safe use, however, is dependent on the availability of a reliable reversal drug. Although widely used, there are concerns with the use of neostigmine for reversal. Arduan is a powerful competitive antagonist of acetylcholine, since it can bind pre- and postsynaptic (N1) receptors of the transmitters.

Dezocine was discovered and patented by American Home Products Corp. in 1978. Dezocine is a partial opiate drug and was used for pain management under brand name Dalgan. But then usage of this drug was discontinued in US. Dezocine acts as a partial μ-receptor agonist, a κ-receptor antagonist, and a norepinephrine and serotonin reuptake inhibitor (via norepinephrine transporter and serotonin transporter). Dezocine shares the CNS depressant and respiratory depressant effects of opioid analgesics. Dezocine has not been shown to produce clinically significant cardiovascular adverse effects.