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

DIMETHOXANATE is a phenothiazine, which is used as a cough suppressant.

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.

Piperidione (Sedulon) is a sedative and antitussive drug used in pulmonary pathology. It was used as a liquid formulation (syrup).

Ethylmorphine is a derivative of morphine with analgesic and antitussive effect. It acts by activating the opioid receptors and thus has a direct influence on the CNS system. Ethylmorphine was approved in Europe for the treatment of dry cough (Codethyline, Dionine).

Eucalyptol is a natural organic compound with fresh mint-like smell and a spicy, cooling taste. Eucalyptol comprises up to 90 percent of the essential oil of some species of the generic product Eucalyptus oil, hence the common name of the compound. It is also found in camphor laurel, bay leaves, tea tree, mugwort, sweet basil, wormwood, rosemary, common sage, Cannabis sativa and other aromatic plant foliage. Eucalyptol with a purity from 99.6 to 99.8 percent can be obtained in large quantities by fractional distillation of eucalyptus oil. Eucalyptol is an ingredient in many brands of mouthwash and cough suppressant, as well as an inactive ingredient in body powder. The typical concentrations of eucalyptol in cosmetic products have been reported to be 1.6% in perfume, 0.4% in soap, 0.1% in creams and lotions and 0.04% in detergents. Committee of Experts on Flavouring Substances of the Council of Europe (CEFS) proposed upper levels of 0.1 mg/kg in beverages and 5 mg/kg in food with the exception of 15 mg/kg in candy and confectionery and 50 mg/kg in alcoholic beverages. Eucalyptol controls airway mucus hypersecretion and asthma via anti-inflammatory cytokine inhibition. Eucalyptol is an effective treatment for nonpurulent rhinosinusitis. Eucalyptol reduces inflammation and pain when applied topically.

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.

Stepronin is clinically used as an expectorant. It inhibits airway secretion in vitro by both decreasing Cl- secretion from epithelial cells and mucus glycoprotein secretion from submucosal glands. The mucolytic activity of stepronine does not involve the gastric mucous coating and that the drug does not exert adverse effects on the gastric mucosa. It is a new chemical immunosuppressant drug, which has the effect of preventing graft-versus-host-disease (GVHD) in a mouse model. The mechanism by which this compound acts as an immunosuppressant appears to be similar to cyclosporine A (CyA), although, in contrast to CyA, it is not toxic for animals and humans. Stepronin has an antiviral effect as well and is able to block, indirectly, the human immunodeficiency virus–1 (HIV-1) replication in mononuclear cells in vitro.

Cloperastine (INN) or cloperastin is an antitussive and antihistamine that is marketed as a cough suppressant in Japan, Hong Kong, and in some European countries. It was first introduced in 1972 in Japan, and then in Italy in 1981. The precise mechanism of action of cloperastine is not fully clear, but several different biological activities have been identified for the drug, of which include: ligand of the gamma1 receptor (Ki = 20 nM) (likely an agonist), GIRK channel blocker (described as "potent"), antihistamine (Ki = 3.8 nM for the H1 receptor), and anticholinergic. Cloperastine possesses dual activity. It also acts as a mild bronchorelaxant and has antihistaminic activity, without acting on the central nervous system or the respiratory center.

S-Carboxymethylcysteine (carbocysteine or SCMC; also available in the lysinate form, SCMC-Lys) is a mucoactive drug, has antioxidant and anti-inflammatory properties. Carbocysteine has been recently recognized as an effective and safe treatment for the long-term management of COPD, able to reduce the incidence of exacerbations and improve patient quality of life. Moreover, carbocysteine was effective in counteracting some symptoms associated with cancer cachexia. Preclinical and clinical studies have demonstrated that the antioxidant and anti-inflammatory properties of carbocysteine are more important than mucolysis itself for its therapeutic efficacy. Therefore, carbocysteine may be able to reverse the oxidative stress associated with several chronic inflammatory diseases, such as cardiovascular diseases and neurodegenerative disorders.