Antisialagogues are drugs or substances that decrease the flow rate of saliva and their effect is opposite to that of sialagogues. [1] Their origin may be both natural and synthetic.
Anticholinergics generally have antisialagogue effects, and most produce some level of sedation, both being advantageous in surgical procedures. [2]
Classic antisialagogues [1] include:
Cannabinoids are several structural classes of compounds found in the cannabis plant primarily and most animal organisms or as synthetic compounds. The most notable cannabinoid is the phytocannabinoid tetrahydrocannabinol (THC) (delta-9-THC), the primary psychoactive compound in cannabis. Cannabidiol (CBD) is also a major constituent of temperate cannabis plants and a minor constituent in tropical varieties. At least 113 distinct phytocannabinoids have been isolated from cannabis, although only four have been demonstrated to have a biogenetic origin. It was reported in 2020 that phytocannabinoids can be found in other plants such as rhododendron, licorice and liverwort, and earlier in Echinacea.
A designer drug is a structural or functional analog of a controlled substance that has been designed to mimic the pharmacological effects of the original drug, while avoiding classification as illegal and/or detection in standard drug tests. Designer drugs include psychoactive substances that have been designated by the European Union as new psychoactive substances (NPS) as well as analogs of performance-enhancing drugs such as designer steroids. Some of these were originally synthesized by academic or industrial researchers in an effort to discover more potent derivatives with fewer side effects and shorter duration and were later co-opted for recreational use. Other designer drugs were prepared for the first time in clandestine laboratories. Because the efficacy and safety of these substances have not been thoroughly evaluated in animal and human trials, the use of some of these drugs may result in unexpected side effects.
THC-O-acetate is the acetate ester of THC. The term THC-O-acetate and its variations are commonly used for two types of the substance, dependent on which cannabinoid it is synthesized from. The difference between Δ8-THC and Δ9-THC is bond placement on the cyclohexene ring.
Synthetic cannabinoids are a class of designer drug molecules that bind to the same receptors to which cannabinoids in cannabis plants attach. These novel psychoactive substances should not be confused with synthetic phytocannabinoids or synthetic endocannabinoids from which they are in many aspects distinct.
JWH-203 (1-pentyl-3-(2-chlorophenylacetyl)indole) is an analgesic chemical from the phenylacetylindole family that acts as a cannabinoid agonist with approximately equal affinity at both the CB1 and CB2 receptors, having a Ki of 8.0 nM at CB1 and 7.0 nM at CB2. It was originally discovered by, and named after, John W. Huffman, but has subsequently been sold without his permission as an ingredient of synthetic cannabis smoking blends. Similar to the related 2'-methoxy compound JWH-250, the 2'-bromo compound JWH-249, and the 2'-methyl compound JWH-251, JWH-203 has a phenylacetyl group in place of the naphthoyl ring used in most aminoalkylindole cannabinoid compounds, and has the strongest in vitro binding affinity for the cannabinoid receptors of any compound in the phenylacetyl group.
JWH-019 is an analgesic chemical from the naphthoylindole family that acts as a cannabinoid agonist at both the CB1 and CB2 receptors. It is the N-hexyl homolog of the more common synthetic cannabinoid compound JWH-018. Unlike the butyl homolog JWH-073, which is several times weaker than JWH-018, the hexyl homolog is only slightly less potent, although extending the chain one carbon longer to the heptyl homolog JWH-020 results in dramatic loss of activity. These results show that the optimum side chain length for CB1 binding in the naphthoylindole series is the five-carbon pentyl chain, shorter than in the classical cannabinoids where a seven-carbon heptyl chain produces the most potent compounds. This difference is thought to reflect a slightly different binding conformation adopted by the naphthoylindole compounds as compared to the classical cannabinoids, and may be useful in characterizing the active site of the CB1 and CB2 receptors.
A-834,735 is a drug developed by Abbott Laboratories that acts as a potent cannabinoid receptor full agonist at both the CB1 and CB2 receptors, with a Ki of 12 nM at CB1 and 0.21 nM at CB2. Replacing the aromatic 3-benzoyl or 3-naphthoyl group found in most indole derived cannabinoids with the 3-tetramethylcyclopropylmethanone group of A-834,735 and related compounds imparts significant selectivity for CB2, with most compounds from this group found to be highly selective CB2 agonists with little affinity for CB1. However, low nanomolar CB1 binding affinity is retained with certain heterocyclic 1-position substituents such as (N-methylpiperidin-2-yl)methyl (cf. AM-1220, AM-1248), or the (tetrahydropyran-4-yl)methyl substituent of A-834,735, resulting in compounds that still show significant affinity and efficacy at both receptors despite being CB2 selective overall.
JWH-198 is a drug from the aminoalkylindole and naphthoylindole families which acts as a cannabinoid receptor agonist. It was invented by the pharmaceutical company Sanofi-Winthrop in the early 1990s. JWH-198 has a binding affinity at the CB1 receptor of 10 nM, binding around four times more tightly than the parent compound JWH-200, which has no substitution on the naphthoyl ring. It has been used mainly in molecular modelling of the cannabinoid receptors.
MDA-19 (also known as BZO-HEXOXIZID) is a drug that acts as a potent and selective agonist for the cannabinoid receptor CB2, with reasonable selectivity over the psychoactive CB1 receptor, though with some variation between species. In animal studies it was effective for the treatment of neuropathic pain, but did not effect rat locomotor activity in that specific study. The pharmacology of MDA-19 in rat cannabinoid receptors have been demonstrated to function differently than human cannabinoid receptors with MDA-19 binding to human CB1 receptors 6.9x higher than rat CB1 receptors.
UR-144 (TMCP-018, KM-X1, MN-001, YX-17) is a drug invented by Abbott Laboratories, that acts as a selective full agonist of the peripheral cannabinoid receptor CB2, but with much lower affinity for the psychoactive CB1 receptor.
XLR-11 (5"-fluoro-UR-144 or 5F-UR-144) is a drug that acts as a potent agonist for the cannabinoid receptors CB1 and CB2 with EC50 values of 98 nM and 83 nM, respectively. It is a 3-(tetramethylcyclopropylmethanoyl)indole derivative related to compounds such as UR-144, A-796,260 and A-834,735, but it is not specifically listed in the patent or scientific literature alongside these other similar compounds, and appears to have not previously been made by Abbott Laboratories, despite falling within the claims of patent WO 2006/069196. XLR-11 was found to produce rapid, short-lived hypothermic effects in rats at doses of 3 mg/kg and 10 mg/kg, suggesting that it is of comparable potency to APICA and STS-135.
AB-FUBINACA is a psychoactive drug that acts as a potent agonist for the cannabinoid receptors, with Ki values of 0.9 nM at CB1 and 23.2 nM at CB2 and EC50 values of 1.8 nM at CB1 and 3.2 nM at CB2. It was originally developed by Pfizer in 2009 as an analgesic medication but was never pursued for human use. In 2012, it was discovered as an ingredient in synthetic cannabinoid blends in Japan, along with a related compound AB-PINACA, which had not previously been reported.
AB-PINACA is a compound that was first identified as a component of synthetic cannabis products in Japan in 2012.
5F-PB-22 is a designer drug which acts as a cannabinoid agonist. The structure of 5F-PB-22 appears to have been designed with an understanding of structure–activity relationships within the indole class of cannabinoids.
AB-CHMINACA is an indazole-based synthetic cannabinoid. It is a potent agonist of the CB1 receptor (Ki = 0.78 nM) and CB2 receptor (Ki = 0.45 nM) and fully substitutes for Δ9-THC in rat discrimination studies, while being 16x more potent. Continuing the trend seen in other cannabinoids of this generation, such as AB-FUBINACA and AB-PINACA, it contains a valine amino acid amide residue as part of its structure, where older cannabinoids contained a naphthyl or adamantane residue.
ADB-PINACA is a cannabinoid designer drug that is an ingredient in some synthetic cannabis products. It is a potent agonist of the CB1 receptor and CB2 receptor with EC50 values of 0.52 nM and 0.88 nM respectively. Like MDMB-FUBINACA, this compound contains an amino acid residue of tert-leucine.
5F-ADB (also known as 5F-MDMB-PINACA) is an indazole-based synthetic cannabinoid from the indazole-3-carboxamide family, which has been used as an active ingredient in synthetic cannabis products and has been sold online as a designer drug. 5F-ADB is a potent agonist of the CB1 receptor, though it is unclear whether it is selective for this target. 5F-ADB was first identified in November 2014 from post-mortem samples taken from an individual who had died after using a product containing this substance. Subsequent testing identified 5F-ADB to have been present in a total of ten people who had died from unexplained drug overdoses in Japan between September 2014 and December 2014. 5F-ADB is believed to be extremely potent based on the very low levels detected in tissue samples, and appears to be significantly more toxic than earlier synthetic cannabinoid drugs that had previously been sold.
THJ-2201 is an indazole-based synthetic cannabinoid that presumably acts as a potent agonist of the CB1 receptor and has been sold online as a designer drug.
ADB-CHMINACA (also known as MAB-CHMINACA) is an indazole-based synthetic cannabinoid. It is a potent agonist of the CB1 receptor with a binding affinity of Ki = 0.289 nM and was originally developed by Pfizer in 2009 as an analgesic medication. It was identified in cannabinoid blends in Japan in early 2015.
5F-MDMB-PICA is a designer drug and synthetic cannabinoid. In 2018, it was the fifth-most common synthetic cannabinoid identified in drugs seized by the Drug Enforcement Administration.