ATC Group: D11AX Other dermatologicals

Brimonidine is an alpha₂-adrenergic receptor agonist that is 1000-fold more selective for the alpha₂-adrenoceptor than the alpha₁-adrenoreceptor. This selectivity results in no mydriasis and the absence of vasoconstriction in microvessels associated with human retinal xenografts.

Caffeine is structurally related to the methylxanthines theophylline and theobromine. Caffeine’s main action is as a CNS stimulant.

Calcium gluconate is the gluconate salt of calcium. An element or mineral necessary for normal nerve, muscle, and cardiac function, calcium as the gluconate salt helps to maintain calcium balance and prevent bone loss when taken orally.

Deoxycholic acid is a cytolytic drug, which when injected into localized subcutaneous fat, physically disrupts the cell membrane of adipocytes. The destruction of adipocytes elicits a tissue response in which macrophages are attracted to the area to eliminate cellular debris and lipids, which are then cleared through natural processes.

Diclofenac is a non-steroidal anti-inflammatory drug. The mechanism of action of diclofenac in AK may be related to the inhibition of the cycloxygenase pathway leading to reduced prostaglandin E₂ (PGE₂) synthesis. In addition, immunohistochemistry (IHC) from skin biopsies ac revealed that the clinical effects of diclofenac in AK are primarily due to anti-inflammatory, anti-angiogenic and possibly anti-proliferative effects and apoptosis-inducing mechanisms.

Eflornithine irreversibly inhibits ornithine decarboxylase, an enzyme involved in the production of the hair shaft by the hair follicle. Eflornithine has been shown to reduce the rate of hair growth.

Finasteride is a competitive inhibitor of human 5α-reductase, an intracellular enzyme which metabolises testosterone into the more potent androgen, dihydrotestosterone (DHT). In benign prostatic hyperplasia (BPH), enlargement of the prostate gland is dependent upon the conversion of testosterone to DHT within the prostate. Finasteride is highly effective in reducing circulating and intraprostatic DHT. Finasteride has no affinity for the androgen receptor.

Hydroquinone is a skin bleaching agent. Topical application of hydroquinone produces a reversible depigmentation of the skin by inhibition of the enzymatic oxidation of tyrosine to 3,4-dihydroxyphenylalanine (dopa).

Ivermectin is a member of the avermectin class and has high affinity with glutamate-gated chloride channels present in invertebrate nerve and muscle cells. Its binding to these channels promotes an increase in membrane permeability to chloride ions, leading to hyperpolarization of the neural or muscle cell. This results in neuromuscular paralysis and may lead to the death of certain parasites.

Little is known about the way the lithium ion can modify neurotransmission within the CNS. Many of the proposed mechanisms have suggested an inhibitory effect on components of various neurotransmitter signalling pathways, such as cyclic AMP formation, cyclic GMP formation, G-proteins or inositol phosphate metabolism.

Magnesium sulfate is a saline purgative. It can be employed locally in various inflammatory conditions, due to its osmotic action.

Topical administration of minoxidil stimulates hair growth in men and women with androgenic alopecia. The mechanism of stimulating hair growth from minoxidil is not fully understood, but some actions of minoxidil include increasing hair diameter, stimulating new growth and prolonging the developmental phase, and stimulating hair follicle transition from resting phase (telogen) in the growth phase (regenerative).

Tiratricol (3,3',5-triiodothyroacetic acid) is a naturally circulating metabolite of active thyroid hormone (T3) with a high degree of structural similarity and follows the same downward degradation pathway (deiodination and conjugation) and elimination via bile and urine. Tiratricol has been demonstrated to be able to enter MCT8 dependent cells without a functioning MCT8 transporter unlike T3 and T4. Tiratricol can thereby replace T3 in MCT8 dependent tissues and restore normal thyroid hormone activity across tissues.