Cyclosporins are cyclic polypeptide macrolides that were originally derived from the soil fungus Tolypocladium inflatum. Cyclosporine (also known as cyclosporine A) was discovered by Sandoz and developed for the tretment of immune disorders. The drug was approved by FDA for such diseases as Rheumatoid Arthritis, Psoriasis (Neoral), Keratoconjunctivitis sicca (Restasis) and prevention of transplant rejections (Neoral and Sandimmune). Cyclosporine’s primary immunosuppressive mechanism of action is inhibition of T-lymphocyte function. Upon administration cyclosporine binds to cyclophilin A and thus inhibits calcineurin, leading to immune system suppression.

Ketoconazole is an azole antifungal. Ketoconazole was the first broad-spectrum oral antifungal agent available to treat systemic and superficial mycoses. Evidence of hepatotoxicity associated with its use emerged within the first few years of its approval. Due to its hepatotoxic side effects, oral ketoconazole was withdrawn from the European and Australian markets in 2013. The United States imposed strict relabeling requirements and restrictions for prescription, with Canada issuing a risk communication echoing these concerns. Today, oral ketoconazole is only indicated for endemic mycoses, where alternatives are not available or feasible. Meanwhile, topical ketoconazole is effective, safe, and widely prescribed for superficial mycoses, particularly as the first-line treatment for tinea versicolor. Topically administered ketoconazole is usually prescribed for fungal infections of the skin and mucous membranes, such as athlete's foot, ringworm, candidiasis (yeast infection or thrush), jock itch, and tinea versicolor. Topical ketoconazole is also used as a treatment for dandruff (seborrheic dermatitis of the scalp) and for seborrheic dermatitis on other areas of the body, perhaps acting in these conditions by suppressing levels of the fungus Malassezia furfur on the skin. Ketoconazole interacts with 14-α demethylase, a cytochrome P-450 enzyme necessary for the conversion of lanosterol to ergosterol. This results in inhibition of ergosterol synthesis and increased fungal cellular permeability. Other mechanisms may involve the inhibition of endogenous respiration, interaction with membrane phospholipids, inhibition of yeast transformation to mycelial forms, inhibition of purine uptake, and impairment of triglyceride and/or phospholipid biosynthesis. Ketoconazole can also inhibit the synthesis of thromboxane and sterols such as aldosterone, cortisol, and testosterone. Ketoconazole is active against clinical infections with Blastomyces dermatitidis, Coccidioides immitis, Histoplasma capsulatum, Paracoccidioides brasiliensis.

Geclosporin (Cyclosporine) is an immunosuppressive agent, that is used to prevent rejection of a transplanted organ by the body. Geclosporin is isolated from a fungus, Beauveria nivea, and was first discovered in 1970. By suppressing the immune system, this drug prevents white blood cells from rejecting the transplanted organ. Geclosporin primarily does this by suppressing T cells and T cell cytokine production, but also acts in other ways, for example by inhibiting growth and activation of B cells and antigen presenting cells, and by reducing antibody production. Geclosporin is usually combined with other compounds, and has been studied as potential treatment for a large range of disorders. It is used for the treatment of several other conditions, such as severe recalcitrant plaque psoriasis, severe active rheumatoid artritis, and to prevent rejection of donor cells as a result of bone marrow transplantation. Relapse after discontinuation of this compound is to be expected, and therefore, patients should receive maintenance therapy at the lowest effective dosage. The most common adverse events are hypertrichosis, gingival hyperplasia, and neurological and gastrointestinal effects. Renal dysfunction is also possible, but irreversible damage is rare.

Enisoprost is a prostaglandin E1 analog. Enisoprost exerts immunosuppressive activity and gastric antisecretory effect. Enisoprost was being studied for the treatment of peptic ulcer and transplant rejection. Enisoprost development has been discontinued.

Rioprostil is a methylprostaglandin E1 analog. Rioprostil inhibits gastric acid secretion and enhances the gastric mucus-bicarbonate barrier. In peptic ulcer cases, it facilitates the healing process and the elimination of pain. Rioprostil can also be used to prevent recurrence of duodenal ulcers. However, its development has been discontinued in 2000.

The ciclosporin analogue ciclosporin H is a potent and selective inhibitor of mediator release from basophils induced by activation of the formyl peptide receptor, and therefore has potential as an anti-inflammatory agent. It acts by interfering with agonist binding to formylmethionylleucylphenylalanine (FMLP) receptors. Unlike ciclosporin [ciclosporin A], ciclosporin H has Dmethyl valine (rather than the Lisomer) at position 11, has an extremely low affinity for cyclophilin, and is devoid of immunosuppressive activity. Ciclosporin H was undergoing preclinical investigation with researchers at the University of Naples Federico II in Italy as an antiinflammatory agent. However, no recent development has been reported.