Emetine is a principal alkaloid of ipecac, isolated from the ground roots of Uragoga ipecacuanha. Early use of emetine was in the form of oral administration of the extract of ipecac root, or ipecacuanha. This extract contains several, including cephaeline, and others. The identification of emetine as a more potent agent improved the treatment of amoebiasis. While the use of emetine still caused nausea, it was more effective than the crude extract of ipecac root. Additionally, emetine could be administered hypodermically which still produced nausea, but not to the degree experienced in oral administration. Emetine dihydrochloride hydrate is used in the laboratory to block protein synthesis in eukaryotic cells. It does this by binding to the 40S subunit of the ribosome. Emetine induces hypotension by blocking adrenoreceptors. Also, emetine was identified as a specific inhibitor of HIF-2α protein stability and transcriptional activity. Heavy or over usage of emetine can carry the risk of developing proximal myopathy and/or cardiomyopathy.

Emetine is a principal alkaloid of ipecac, isolated from the ground roots of Uragoga ipecacuanha. Early use of emetine was in the form of oral administration of the extract of ipecac root, or ipecacuanha. This extract contains several, including cephaeline, and others. The identification of emetine as a more potent agent improved the treatment of amoebiasis. While the use of emetine still caused nausea, it was more effective than the crude extract of ipecac root. Additionally, emetine could be administered hypodermically which still produced nausea, but not to the degree experienced in oral administration. Emetine dihydrochloride hydrate is used in the laboratory to block protein synthesis in eukaryotic cells. It does this by binding to the 40S subunit of the ribosome. Emetine induces hypotension by blocking adrenoreceptors. Also, emetine was identified as a specific inhibitor of HIF-2α protein stability and transcriptional activity. Heavy or over usage of emetine can carry the risk of developing proximal myopathy and/or cardiomyopathy.

Chlorobutanol, or trichloro-2-methyl-2-propanol, is an analgesic and sedative hypnotic in man, and an experimental general anesthetic. It has antibacterial and antifungal properties. It is also used chemical preservative for parenteral drugs. It was found, that chlorobutanol inhibited mammalian Nav 1.2 channels at concentrations less than those used to preserve parenteral solutions. Its mechanism of inhibiting Na channels differs from that of local anesthetics in that it does not show use dependent or state dependent inhibition.

Procaine is an anesthetic agent indicated for production of local or regional anesthesia, particularly for oral surgery. Procaine (like cocaine) has the advantage of constricting blood vessels which reduces bleeding, unlike other local anesthetics like lidocaine. Procaine is an ester anesthetic. It is metabolized in the plasma by the enzyme pseudocholinesterase through hydrolysis into para-aminobenzoic acid (PABA), which is then excreted by the kidneys into the urine. Procaine acts mainly by inhibiting sodium influx through voltage gated sodium channels in the neuronal cell membrane of peripheral nerves. When the influx of sodium is interrupted, an action potential cannot arise and signal conduction is thus inhibited. The receptor site is thought to be located at the cytoplasmic (inner) portion of the sodium channel. Procaine has also been shown to bind or antagonize the function of N-methyl-D-aspartate (NMDA) receptors as well as nicotinic acetylcholine receptors and the serotonin receptor-ion channel complex.

Noscapine (also known as Narcotine, Nectodon, Nospen, Anarcotine and (archaic) Opiane) is a benzylisoquinoline alkaloid from plants of the poppy family, without painkilling properties. This agent is primarily used for its antitussive (cough-suppressing) effects. Noscapine is often used as an antitussive medication. A 2012 Dutch guideline, however, does not recommend its use for coughing. Noscapine can increase the effects of centrally sedating substances such as alcohol and hypnotics. Noscapine should not be taken in conjunction with warfarin as the anticoagulant effects of warfarin may be increased. Noscapine, and its synthetic derivatives called noscapinoids, are known to interact with microtubules and inhibit cancer cell proliferation. Mechanisms for its antitussive action are unknown, although animal studies have suggested central nervous system as a site of action. Furthermore, noscapine causes apoptosis in many cell types and has potent antitumor activity against solid murine lymphoid tumors (even when the drug was administered orally) and against human breast and bladder tumors implanted in nude mice. Because noscapine is water-soluble and absorbed after oral administration, its chemotherapeutic potential in human cancer merits thorough evaluation. Antifibrotic effect of noscapine based on novel mechanism, which it shows through EP2 prostaglandin E2 receptor-mediated activation of protein kinase A.

Lobeline is an alkaloid found in "Indian tobacco" (Lobelia inflata), "Devil's tobacco" (Lobelia tupa), "cardinal flower" (Lobelia cardinalis), "great lobelia" (Lobelia siphilitica), and Hippobroma longiflora. Additionally, it is also found in Lobelia Chinensis. In its pure form, it is a white amorphous powder which is freely soluble in water. Lobeline has been sold, in tablet form, for use as a smoking cessation aid, and may have application in the treatment of other drug addictions such as addiction to amphetamines, cocaine, or alcohol. Lobeline has multiple mechanisms of action, acting as a VMAT2 ligand, which stimulates dopamine release to a moderate extent when administered alone, but reduces the dopamine release caused by methamphetamine. It also inhibits the reuptake of dopamine and serotonin and acts as a mixed agonist-antagonist at nicotinic acetylcholine receptors to which it binds at the subunit interfaces of the extracellular domain. It is also an antagonist at μ-opioid receptors. It seems to be a P-glycoprotein inhibitor, according to at least one study. It has been hypothesized that P-glycoprotein inhibition reduces chemotherapeutic resistance in cancer, presumably affecting any substrates of P-gp.

Pyridoxal phosphate (PLP, pyridoxal 5'-phosphate, P5P) is a coenzyme, the active form of vitamin B6. Pyridoxal 5′-phosphate (PLP) is used as a cofactor for a wide range of enzymes including mitochondrial cysteine desulfurase, cystathionine γ-synthase (CGS), ornithine 4,5-aminomutase (OAM), and d-serine dehydratase. The versatility of PLP arises from its ability to covalently bind the substrate, and then to act as an electrophilic catalyst, thereby stabilizing different types of carbanionic reaction intermediates. PLP acts as a coenzyme in all transamination reactions, in various beta-elimination reactions, in the condensation reaction in heme synthesis.

An alkaloid found in opium but not closely related to the other opium alkaloids in its structure or pharmacological actions. Papaverine is a vasodilating agent. Papaverine is used for the treating certain conditions that are accompanied by smooth muscle spasms (eg, blood vessel, urinary, gallbladder, or intestinal spasm). Papaverine is a nonxanthine phosphodiesterase inhibitor for the relief of cerebral and peripheral ischemia associated with arterial spasm and myocardial ischemia complicated by arrhythmias. The main actions of Papaverine are exerted on cardiac and smooth muscle. Like qathidine, Papaverine acts directly on the heart muscle to depress conduction and prolong the refractory period. Papaverine relaxes various smooth muscles. This relaxation may be prominent if spasm exists. The muscle cell is not paralyzed by Papaverine and still responds to drugs and other stimuli causing contraction. The antispasmodic effect is a direct one, and unrelated to muscle innervation. Papaverine is practically devoid of effects on the central nervous system. Papaverine relaxes the smooth musculature of the larger blood vessels, especially coronary, systemic peripheral, and pulmonary arteries. Papaverine is a potent, specific inhibitor of PDE10A. Papaverine for treatment of erectile dysfunction (ED) is excluded from coverage.

p-Chlorocresol (p-chloro-m-cresol; PCMC; brand name: Preventol CMK) possesses disinfectant and antiseptic properties. Chlorocresol is used in various preparations for skin disinfection and wounds. It also used as a preservative in creams and other preparations for external use which contain water. For use as a disinfectant such as a hand wash, it is commonly dissolved in alcohol in combination with other phenols. It is a moderate allergen for sensitive skin. Chlorocresol produces potentially life-threatening effects which include dermatitis, which are responsible for the discontinuation of chlorocresol therapy. The symptomatic adverse reactions produced by chlorocresol are more or less tolerable and if they become severe, they can be treated symptomatically, these include hypersensitivity reactions, irritation of eyes.