Quazolast (RHC 3988) is a potent mediator release inhibitor and is a control against ragweed antigenic nasal challenge. quazolast is superior to placebo in preventing nasal congestion and nasal itching following ragweed nasal challenge.

Fexofenadine (Carboxyterfenadine), an antihistamine pharmaceutical drug, is used to treat allergy symptoms, such as nasal congestion, hay fever, and urticaria. Compared to first-generation antihistamines, Fexofenadine is less able to pass the blood-brain barrier and cause sedation.

Terpin hydrate, a cis-form hydrate, is derived from sources such as oil of turpentine, oregano, thyme, and eucalyptus. It is used as an insect repellent and expectorant. Terpin hydrate(cis-Terpin hydrate) is commonly used to loosen mucus and ease congestion in patients presenting with acute or chronic bronchitis, and related pulmonary conditions. It was popular in the United States since the late nineteenth century, but was removed from marketed medications in the 1990s after the U.S. Food and Drug Administration (FDA) stated that based on the evidence currently available, there are inadequate data to establish general recognition of the safety and effectiveness of these ingredients . Elixirs of terpin hydrate are still available with a prescription but must be prepared by a compounding pharmacy.

Epimagnolin A is a lignan obtained from the flower buds of Magnolia fargesii, which is traditionally used in Asian medicine for treating headache and nasal congestion.

Nebentan (YM598) is a potent, selective and orally active non-peptide endothelin ETA receptor antagonist through the modification of Bosentan . Nebentan inhibits [125I] endothelin-1 binding to cloned human endothelin ETA and ETB receptor, with Ki of 0.697 nM and 569 nM, respectively[1]. YM598 can ameliorate the progression of cor pulmonale and myocardial infarction in vivo[2]. Nebentan inhibits the specific binding of [125I] endothelin-1 to endothelin ETA and ETB receptors in a concentration dependent manner,Ki values are 0.697 nM and 1.53 nM for human and rat endothelin ETA receptors, respectively. In contrast, YM598 exhibits low affinities for human and rat endothelin ETB receptors, with Ki values of 569 nM and 155 nM,respectively[1].In measurement of intracellular Ca2+ concentration, Nebentan concentration-dependently inhibits the increase in [Ca2+]i induced by 10 nM endothelin-1 in both CHO cells and A10 cells, the IC50 values are 26.2 nM for CHO cells and 26.7 nM for A10 cells, respectively[1]. Nebentan (oral administration; 0.1-1 mg/kg; 4 weeks) significantly inhibits the progression of pulmonary hypertension and the development of right ventricular hypertrophy[2].Nebentan (oral administration; 1 mg/kg; 30 weeks) significantly ameliorates the poor survival rate of CHF rats, it markedly reduces the hypertrophy of both ventricles as well as pulmonary congestion[2]. [1]. Hironori Yuyama, et al. Pharmacological Characterization of YM598, an Orally Active and Highly Potent Selective Endothelin ET(A) Receptor Antagonist. Eur J Pharmacol. 2003 Sep 30;478(1):61-71. [2]. Akira Fujimori, et al. YM598, an Orally Active ET(A) Receptor Antagonist, Ameliorates the Progression of Cardiopulmonary Changes and Both-Side Heart Failure in Rats With Cor Pulmonale and Myocardial Infarction. J Cardiovasc Pharmacol. 2004 Nov;44 Suppl 1:S354-7.

Tetrahydrozoline hydrochloride (Murine Plus) is an imidazoline derivative with alpha receptor agonist activity.

Naphazoline nitrate is an α1-Adrenergic receptor agonist. It also induces autophagy and necrotic cell death in erythroleukemia cells and inhibits erythroid differentiation. It used to treat congestion and ocular pathologies.

Aniline-d5 is a deuterated compound of Aniline. Aniline has a CAS number of 62-53-3. Aniline has been reported to be toxic to the spleen via iron overload and induction of oxidative stress via Heme Oxygenase 1 up-regulation. Toxicity of this agent on the spleen is characterized by hyperplasia, fibrosis, and vascular congestion in rats. Studies suggest that this compound causes significant increase in both p-IKKα and p-IKKβ which in-turn increases NF-κB and AP-1 binding activity. In other experiments, Aniline displays a capacity to induce methemoglobinemia, glutathione depletion, membrane cytoskeletal changes, loss of circulating blood cells, and adversely affects blood stability.

Sovesudil (PHP-201) hydrochloride is a potent, ATP-competitive, locally acting Rho kinase (ROCK) inhibitor that acts on ROCK I (IC50: 3.7 nM) and ROCK II (IC50: 2.3 nM). Sovesudil hydrochloride is capable of lowering IOP without causing congestion.

Povafonidine (PGE-6201204) is a potent alpha-2 adrenoreceptor agonist. Povafonidine can constrict blood vessels and reduce mucosal congestion which can be used for nasal congestion research [1].

Tetrahydrozoline (Tetryzoline) nitrate is a derivative of imidazoline. It is an α-adrenergic agonist that causes vasoconstriction. Tetrahydrozoline is widely used for the nasal congestion and conjunctival congestion research [1] [2].

Synephrine (Oxedrine) is sympathetic alpha-adrenergic agonist used as a vasoconstrictor in circulatory failure, asthma, nasal congestion, and glaucoma.

OxyMetazoline is an α-adrenoceptor agonist that acts on α1A (IC50: 0.02 μM), α1B (IC50: 0.25 μM), α2A (IC50: 0.58 μM) and α2C (IC50: 0.13 μM). OxyMetazoline can be used in studies to relieve nasal mucosal congestion.

Tetrahydrozoline (Tetryzoline), an alpha agonist, have an effect on the constriction of conjunctival blood vessels. This contributes to relieve the redness of the eye resulted from minor ocular irritants.

Thonzylamine (neohetramine) is an antihistamine and anticholinergic drug. It is available as combination products with Clofedanol or Phenylephrine for temporary relief of symptoms of common cold, hay fever (allergic rhinitis) or other upper respiratory allergies.

Clocoumarol is an anticoagulant that prevents blood clotting. It also can inhibit the dilatation of the spleen and the congestion of lymph nodes.