Nedocromil is a medication considered as mast cell stabilizer used to treat itching associated with allergic conjunctivitis. Nedocromil has been shown to inhibit the in vitro activation of, and mediator release from, a variety of inflammatory cell types associated with asthma, including eosinophils, neutrophils, macrophages, mast cells, monocytes, and platelets. Nedocromil inhibits activation and release of inflammatory mediators such as histamine, prostaglandin D2 and leukotrienes c4 from different types of cells in the lumen and mucosa of the bronchial tree. These mediators are derived from arachidonic acid metabolism through the lipoxygenase and cyclo-oxygenase pathways. The mechanism of action of nedocromil may be due partly to inhibition of axon reflexes and release of sensory neuropeptides, such as substance P, neurokinin A, and calcitonin-geneñrelated peptides. The result is inhibition of bradykinin-induced bronchoconstriction. Nedocromil does not possess any bronchodilator, antihistamine, or corticosteroid activity. Nedocromil is indicated for the treatment of itching associated with allergic conjunctivitis.

Clofazimine (Lamprene®) is a fat-soluble riminophenazine dye used for the treatment of leprosy. It has been used investigationally in combination with other antimycobacterial drugs to treat Mycobacterium avium infections in AIDS patients. Clofazimine (Lamprene®) exerts a slow bactericidal effect on Mycobacterium leprae (Hansen’s bacillus). It inhibits mycobacterial growth and binds preferentially to mycobacterial DNA. It also exerts anti-inflammatory properties in controlling erythema nodosum leprosum reactions. However, its precise mechanisms of action are unknown.

Cinoxacin is a synthetic antibacterial agent for oral administration. Cinoxacin mode of action involves the inhibiting of DNA gyrase, a type II topoisomerase, and topoisomerase IV. Adverse effects are nausea, anorexia, vomiting, abdominal cramps/pain, perverse taste, diarrhea, headache, dizziness, rash, urticaria, pruritus, edema and other.

Oxolinic acid is a synthetic quinolone antibiotic related to nalidixic acid. It is authorized in veterinary medicine for use in finfish, calves, pigs, and poultry. It acts by inhibiting bacterial type II topoisomerase activity. Oxolinic acid has been used in human medicine in several countries in the past. Its use in human medicine has largely been replaced by the fluoroquinolone antibiotics.

Trioxsalen (trimethylpsoralen, trioxysalen or trisoralen) is a furanocoumarin and a psoralen derivative. It is obtained from several plants, mainly Psoralea corylifolia. Like other psoralens it causes photosensitization of the skin. It is administered either topically or orally in conjunction with UV-A (the least damaging form of ultraviolet light) for phototherapy treatment of vitiligo1 and hand eczema.2 After photoactivation it creates interstrand cross-links in DNA, which can cause programmed cell death unless repaired by cellular mechanisms. In research it can be conjugated to dyes for confocal microscopy and used to visualize sites of DNA damage.3 The compound is also being explored for development of antisense oligonucleotides that can be cross-linked specifically to a mutant mRNA sequence without affecting normal transcripts differing at even a single base pair.Trioxsalen was discontinued by the manufacturer in December 2002.

Methysergide is an oral, synthetic ergot alkaloid, structurally related to the oxytocic agent methylergonovine and to the potent hallucinogen LSD. Methysergide is used prophylactically to reduce the frequency and intensity of severe vascular headaches. Although methysergide is an ergot alkaloid, it is a weak vasoconstrictor and oxytocic. Methysergide is a more potent antagonist of peripheral serotonin receptors than other ergot alkaloids. Methysergide is not just a 5HT2 antagonist, it is also a 5HT1 agonist. Although methysergide and sumatriptan both stimulate serotonin receptors centrally, methysergide is intended for prophylaxis while sumatriptan is indicated for treatment of an acute attack. Methysergide was approved by the FDA in 1962. Methysergide was formerly used for prophylaxis of cluster headaches/migraine headaches, but is no longer recommended due to retroperitoneal/retropulmonary fibrosis.