Mequitamium iodide (LG 30435) is a quaternary ammonium phenothiazine. Mequitamium iodide was found to bind with high affinity only to histamine H1 receptors and to muscarinic acetylcholine receptors. The (+)-(S)-enantiomer is 10-fold more potent than (-)-(R)-enantiomer as a histamine antagonist, while the two enantiomers show the same antimuscarinic activity in vitro. In animal models, it exerts antiasthmatic and antiallergic properties. It was being clinically investigated as a treatment of asthma and rhinitis.

Clorisamine is an antihistamine drug developed by Schering in the 1970s. The drug was evaluated in phase 1 clinical trial on healthy volunteers. The results show that in a therapeutic dose of 2 mg the drug did not have any effects which might lead to an impairment of driving ability.

Oglufanide, an angiogenesis inhibitor, an immunomodulator, that originally was developed and registered in Russia under the brand name timogen. Oglufanide inhibits vascular endothelial growth factor (VEGF), which may inhibit angiogenesis. This agent has also been reported to stimulate the immune response to hepatitis C virus and intracellular bacterial infections. Oglufanide was studied in the USA for the treatment of cancer, and in September 2001, it was granted Orphan Drug designation for the treatment of ovarian cancer. In addition, in Australia this drug was involved in phase II clinical trial for the treatment of hepatitis C. Oglufanide is also participated in phase III trials for patients with Kaposi's sarcoma, however, this study was discontinued.

Napactadine is a bicyclic antidepressant agent. It is a histamine-H1 receptor antagonist. Preliminary results indicated a marked improvement in depressive symptomalology within 7 days of treatment, as measured by the Hamilton depression scale. However, clinical studies were discontinued after chronic administration of napactadine because an elevation in liver enzyme levels was observed in some patients.

Pyroxamine (also known as AHR 224) is benzhydryl ethers of 3-pyrrolidinol patented by A. H. Robins Co., Inc. as antihistamine with bronchodilation activity. In preclinical studies, Pyroxamine shows moderate inhibition of histamine-induced ulceration in guinea pigs

Omtriptolide (previously known as PG490-88 or F60008), an immunosuppressant that has been shown to be the safe and potent antitumor agent and it has been approved entry into Phase I clinical trial for the treatment of prostate cancer in the USA. In addition, the drug is participating in phase I clinical trial for the treatment of myeloid leukemia. Experiments on animals have shown omtriptolide was highly effective in the prevention of murine graft-versus-host disease (GVHD). The immunosuppressive effect of the drug was mediated by inhibition of alloreactive T cell expansion through interleukin-2 production. However, this study was discontinued. Recently published article has shown omtriptolide possesses the potential as a prophylactic agent to prevent ischemia/reperfusion (I/R)-induced lung injury.

Amoxydramine is tertiary dialkylarylcarbinol derivative patented by American chemical company Allied Chemical Corp as an antitussive, sedative, and antihypertensive agent.

Diethazine is the antimuscarinic agent. It has actions similar to those of ethopropazine but it is more toxic. Diethazine is used for the palliative treatment of the parkinsonian syndrome. It is more useful in the treatment of Parkinson’s disease than in allergies. Blockade of single contractions observed in these experiments after administration of diethazine was independent of the frequency of stimulation of the nerve. This suggests that the drug acts directly on the postsynaptic receptor in the endplate.

Omtriptolide (previously known as PG490-88 or F60008), an immunosuppressant that has been shown to be the safe and potent antitumor agent and it has been approved entry into Phase I clinical trial for the treatment of prostate cancer in the USA. In addition, the drug is participating in phase I clinical trial for the treatment of myeloid leukemia. Experiments on animals have shown omtriptolide was highly effective in the prevention of murine graft-versus-host disease (GVHD). The immunosuppressive effect of the drug was mediated by inhibition of alloreactive T cell expansion through interleukin-2 production. However, this study was discontinued. Recently published article has shown omtriptolide possesses the potential as a prophylactic agent to prevent ischemia/reperfusion (I/R)-induced lung injury.