Dextromethorphan is a non-narcotic morphine derivative widely used as an antitussive for almost 40 years. It has attracted attention due to its anticonvulsant and neuroprotective properties. It is a cough suppressant in many over-the-counter cold and cough medicines. In 2010, the FDA approved the combination product dextromethorphan/quinidine for the treatment of pseudobulbar affect. Dextromethorphan suppresses the cough reflex by a direct action on the cough center in the medulla of the brain. Dextromethorphan shows high-affinity binding to several regions of the brain, including the medullary cough center. This compound is an NMDA receptor antagonist and acts as a non-competitive channel blocker. It is one of the widely used antitussives and is used to study the involvement of glutamate receptors in neurotoxicity. Dextromethorphan (DM) is a sigma-1 receptor agonist and an uncompetitive NMDA receptor antagonist. The mechanism by which dextromethorphan exerts therapeutic effects in patients with pseudobulbar affect is unknown. Dextromethorphan should not be taken with monoamine oxidase inhibitors due to the potential for serotonin syndrome. Dextromethorphan is extensively metabolized by CYP2D6 to dextrorphan, which is rapidly glucuronidated and unable to cross the blood-brain barrier.

Camphor is a bicyclic monoterpene ketone found widely in plants, especially cinnamomum camphora. Topically, camphor is used to relieve pain. It has been used to treat warts, cold sores, hemorrhoids, and osteoarthritis. It has also been applied topically as an analgesic and an antipruritic. It has been used as a counterirritant, and to increase local blood flow. Camphor has frequently been used topically to treat respiratory tract diseases involving mucous membrane inflammation. It is sometimes used topically to treat cardiac symptoms. Camphor is also used topically as an eardrop, and for treating minor burns. In inhalation therapy, camphor is used as an antitussive. Orally, camphor is used as an expectorant, antiflatulent, and for treating respiratory tract diseases. Today, most camphor is synthetic. It is approved by the FDA as a topical antitussive. Camphor is produced synthetically from the oil of turpentine. It has been used for centuries for its medicinal features, in religious rituals, and in cooking. It is no longer used as pesticide. In 1982, the US Food and Drug Administration restricted commercial products intended for medicinal use to contain <11% camphor.

Dextrorphan is an active metabolite of dextromethorphan, is an antitussive agent, which was found in cough medicines. Dextrorphan is a noncompetitive N-methyl-D-aspartate receptor (NMDAR) antagonist, sigma 1 receptor agonist, so as is an agonist of mu and kappa opioid receptors. In addition was found, that dextrorphan possessed anticonvulsive and neuroprotective effects.

Verticine is a steroidal alkaloid compound extracted from the Fritillaria species of medicinal plants. Verticine was not only able to block the Nav1.7 ion channel but also preferably inhibited the Kv1.3 ion channel. It inhibits the production of inflammatory cytokines induced by LPS through blocking MAPKs and NF-κB signaling pathways. Verticine inhibited the hERG peak tail currents in a concentration dependent manner. Verticine exhibits anti-inflammatory, antitussive, antihypertensive and pain suppression properties.

Narceine methyl ester and narceine are potent alkaloids which were isolated from Corydalis longipes were found effective in vitro at very low concentration, i.e., 100~500 ppm against spore germination of some test plant pathogenic fungi (Alternaria solani, A. tagetica, Cercospora abelmoschi, Curvularia maculans, Erysiphe cichoracearum, E. pisi, Fusarium udum, Helminthosporium oryzae, H. penniseti, Ustilago cynodontis). George Bell Frankforter was the first person to isolate narceine (in 1893) during his Ph.D. research for August Hofmann at the University of Berlin. Narceine has a weak morphine-like action, but is not much used in medicine. It may be administered in a pill, as a mild hypnotic and to allay cough; it is less depressant than morphine and does not constipate. Ethylnarceine is a narcotic, analgesic, and antitussive.

Narceine methyl ester and narceine are potent alkaloids which were isolated from Corydalis longipes were found effective in vitro at very low concentration, i.e., 100~500 ppm against spore germination of some test plant pathogenic fungi (Alternaria solani, A. tagetica, Cercospora abelmoschi, Curvularia maculans, Erysiphe cichoracearum, E. pisi, Fusarium udum, Helminthosporium oryzae, H. penniseti, Ustilago cynodontis). George Bell Frankforter was the first person to isolate narceine (in 1893) during his Ph.D. research for August Hofmann at the University of Berlin. Narceine has a weak morphine-like action, but is not much used in medicine. It may be administered in a pill, as a mild hypnotic and to allay cough; it is less depressant than morphine and does not constipate. Ethylnarceine is a narcotic, analgesic, and antitussive.

PIPAZETHATE is a non-narcotic oral antitussive agent. It acts centrally on the medullary cough center and is used for the treatment of cough.

Pentoxyverine is a non-opioid antitussive used to prevent cough caused by common cold. It is used as an active ingredient of several oral over-the-counter cough suppressants alone or in combination with other medications, especially decongestants. Certuss is a combination of pentoxyverine and guaifenesin. Pentoxyverine is FDA pregnancy category C drug. Known as anticonvulsant, and spasmolytic agent.

Pentoxyverine is a non-opioid antitussive used to prevent cough caused by common cold. It is used as an active ingredient of several oral over-the-counter cough suppressants alone or in combination with other medications, especially decongestants. Certuss is a combination of pentoxyverine and guaifenesin. Pentoxyverine is FDA pregnancy category C drug. Known as anticonvulsant, and spasmolytic agent.

Pentoxyverine is a non-opioid antitussive used to prevent cough caused by common cold. It is used as an active ingredient of several oral over-the-counter cough suppressants alone or in combination with other medications, especially decongestants. Certuss is a combination of pentoxyverine and guaifenesin. Pentoxyverine is FDA pregnancy category C drug. Known as anticonvulsant, and spasmolytic agent.