Laropiprant is a drug, which was used in combination with nicotinic acid (also known as niacin) and was known under tradename: tredaptive. Tredaptive was indicated as adjunctive therapy to diet for use in patients with primary hypercholesterolaemia (heterozygous familial and non-familial) or mixed dyslipidaemia. The marketing authorisation for Tredaptive has been withdrawn at the request of the marketing-authorisation holder due to increases in side effects with no cardiovascular benefit. Laropiprant is a selective antagonist of the prostaglandin D(2) (PGD(2)) receptor subtype 1 (DP1). It also has the affinity to interact with thromboxane A2 receptor (TP), although it is approximately 190-fold less potent when compared to DP1. Activation of TP has been shown to induce platelet aggregation in vitro, whereas activation of human platelet DP1 inhibits platelet aggregation. These in vitro data indicate that laropiprant may alter platelet function either by enhancement of platelet reactivity through DP1 antagonism or by inhibition of platelet aggregation through TP antagonism. Also were clinical trials phase II for the laropiprant alone, there were shown, that drug did not demonstrate efficacy in asthmatic patients or patients with allergic rhinitis.

Proxyphylline is a xanthine derivative that acts as a cardiac stimulant, vasodilator and bronchodilator. In combination with ephedrine it’s used for relief of acute bronchial asthma and for reversible bronchospasm associated with chronic bronchitis and emphysema. Proxyphylline is readily absorbed from the gastrointestinal tract and it’s not converted to theophylline in the body. The clinical studies are agreed with the property of proxyphylline to inhibit the cyclic nucleotide phosphodiesterases.

Vapiprost is a potent dicyclopentadiene thromboxane receptor antagonist that was being developed by Glaxo Wellcome in Japan. Vapiprost has been shown to be a potent and specific thromboxane (Tx)A2 receptor blocking drug in vitro using platelets and both vascular and airways smooth muscle preparations from different species. The drug is active in various experimental models of thrombosis. The potential clinical applications for a thromboxane receptor blocking drug include the treatment of thrombotic events and occlusive vascular disease. Phase III trials were underway in Japan for the treatment of deep vein thrombosis, which later were discontinued.

DIMEFLINE is a pneumokinetic and respiratory stimulant. It has been used for the treatment of respiratory insufficiency. The mechanism of action is unknown.

Oxilofrine is a sympathomimetic used to treat hypotensive states, with cardiac stimulatory effects similar to those of ephedrine. It has never been approved for use in the USA as a prescription drug or as a dietary supplement. Oxilofrine has been found (1) to act predominantly as a beta1 agonist increasing the speed and force of heart muscle contraction (inotropic effects), specifically, increasing left ventricular ejection fraction and stroke volume; (2) to increase blood pressure; (3) to have variable effects on heart rate; and (4) to potentially increase oxygen uptake by the lungs.

Trimetoquinol hydrochloride dilates bronchial muscle selectively by stimulating Beta 2-receptors. It is used for the relief of bronchoconstriction associated with bronchitis, asthmatic bronchitis and bronchial asthma. Since the concurrent use of the drug with catecholamines such as Epinephrine and Isoproterenol may induce arrythmia or cardiac arrest in some cases, concurrent use is not recommended. Adverse reactions : Palpitation may occur occasionally, and alteration of blood pressure and precordial pain may appear rarely; headache may occur occasionally; tremor, dizziness, feverish sensation may also be encountered in a rare incidence; occasionally, nausea and anorexia may appear.

Seratrodast belongs to a class of medication called thromboxane A2/prostaglandin endoperoxide receptor antagonist. Seratrodast blocks the broncho-constrictor effects of certain chemicals (prostaglandins) in the body. Seratrodast also decreases the inflammation by antagonising the thromboxane A2 receptor. Adverse effects include gastrointestinal disturbances, drowsiness, headache, palpitations, and hepatitis. Seradair may interact with Ozagrel.

APAFANT is a platelet activating factor receptor (PAF-R) antagonist shown to have anticancer and cell differentiation effects. APAFANT has been found to be a specific PAF-R antagonist in pulmonary vasculature and when administered intratracheally in rats. APAFANT was observed to decrease lung nuclear factor-κB (NF-κB) activation, myeloperoxidase activity, and lavage neutrophil numbers. It has been shown to be a cytodifferentiating agent in murine erythroleukemia cells in vitro.

Cilomilast (Ariflo) is an oral selective phosphodiesterase (PDE) IV inhibitor under development by GlaxoSmithKline Pharmaceuticals for treatment of COPD. After the demise of Merck's PDE-IV inhibitor (licensed from Celltech Group) in April 2003, Ariflo has emerged as the frontrunner in this new class of agents for inflammatory airways diseases, such as COPD. GlaxoSmithKline filed for drug approval with the US FDA at the end of 2002 and in January 2003 with the European Medicines Evaluation Agency (EMEA). In October 2003 the FDA issued an approvable letter for use of Ariflo in maintenance of lung function in COPD patients poorly responsive to salbutamol, despite an earlier decision by the FDA advisory panel to reject approval. Cilomilast shows high selectivity for cAMP-specific PDE4, an isoenzyme that predominates in pro-inflammatory and immune cells and that is 10-fold more selective for PDE4D than for PDE4A, -B or -C. In vitro, cilomilastsuppresses the activity of several pro-inflammatory and immune cells that have been implicated in the pathogenesis of asthma and COPD. Moreover, it is highly active in animal models of these diseases. Cilomilast has been shown to exert potent anti-inflammatory effects both in vitro and in vivo.

Pleconaril (Picovir) is an antiviral drug that was being developed by Schering-Plough for prevention of asthma exacerbations and common cold symptoms in patients exposed to picornavirus respiratory infections. Pleconaril binds to a hydrophobic pocket in viral protein 1, the major protein which comprises the capsid (the outer "shell") of picornaviruses. In enteroviruses, this prevents the virus from exposing its RNA, and in rhinoviruses, it also prevents the virus from attaching itself to the host cell. The results of two randomized, double-blind, placebo studies found Pleconaril treatment could benefit patients suffering from colds due to picornaviruses. Participants in the studies were healthy adults from Canada and the United States, with self-diagnosed colds that had occurred within 24 hours of trial enrollment. Participants were randomly given a placebo or two 200 mg tablets to take three times daily for five days. To increase absorption it was recommended to be taken after a meal. To monitor the effectiveness of Pleconaril, Participants recorded the severity of their symptoms and nasal mucosal samples were obtained at enrollment, day 3, day 6 and day 18. The two studies had a total of 2096 participates and more than 90% (1945) completed the trial. The most common reason for a participant not finishing the trial was an adverse event. Pleconaril treatment showed a reduction in nose blowing, sleep disturbance, and less cold medication used. The U.S. Food and Drug Administration rejected pleconaril in 2002 due to the side effects. The most commonly reported side effects were mild to a moderate headache, diarrhea, and nausea.