Acne is a multifactorial inflammatory disease that affects the skin’s oil glands and hair follicles. Current acne treatments target the three main factors leading to breakouts: excess sebum production, bacteria growth, and clogged pores. This pharmacology lecture covers topics such as pathophysiology of acne formation, overproduction of sebum, follicular hyperkeratinization, the role of P. acnes bacteria, genetic & hormonal influences (the role of estrogen and testosterone), mechanism of action and side effects of common acne treatments; retinoids, pertinent antibiotics, and hormonal therapies. Drugs mentioned include; Tretinoin, Adapalene, Tazarotene, Isotretinoin, Sulfamethoxazole, Trimethoprim, Clindamycin, Doxycycline, Minocycline, Erythromycin, Azithromycin, Benzoyl Peroxide, Spironolactone, and Oral Contraceptives; Ethinyl Estradiol, Norgestimate, Desogestrel.
In this lecture we’re gonna cover the pharmacology so let’s get right into it by first discussing the pathophysiology of acne. that affects the skin’s oil glands and hair follicles. to hair follicles and release a fatty substance acne occurs when sebum and dead skin cells overtime as sebum and dead skin cells accumulate to form an open comedo knows as blackhead or
Closed comedo knows as whitehead. and the third one is presence of acne-causing so, overproduction of sebum is generally the the sebaceous glands, which leads to clogged the most common causes affecting activity our genes influence the size and activity of the sebaceous glands. hormones, which cause the sebaceous glands to enlarge and produce more sebum. cause of acne
That is follicular hyperkeratinization. as a result dead cells tend to clump together, blocking pores and causing a backup of sebum in the follicle. specifically p. acnes that thrives in the oily depths of our pores. causes the bacterium to proliferate and turn now, let’s move on to discussing the mechanism the available pharmacotherapeutic options can be divided into
Three main groups; (1) retinoids, (2) antimicrobials, and (3) hormonal therapy. retinoids are a class of compounds derived similarities with vitamin a. their main targets are epidermal cells known as suprabasal keratinocytes. retinoic acid is then shuttled by cellular the nucleus where it binds to either the retinoic acid receptors (rars) or the retinoid x receptors (rxrs).
On target genes causing activation of transcription factors. and amphiregulin (ar), which through the interaction cause proliferation of basal keratinocytes, through this action, retinoids promote shedding at the surface, which leads to expulsion of mature comedones and suppression of microcomedo formation. now, in general all retinoids share the same agents, oral retinoid
Called isotretinoin that is, it inhibits the proliferation and thereby shrinking the sebaceous glands and decreasing sebum production. number of leukocytes that aggregate at the now, when it comes to side effects topical agents are known to cause skin dryness, irritation, oral isotretinoin, on the other hand, is much and thus is associated with more severe side or bone pain,
And gastrointestinal disorders among many others. now let’s move on to our second group of drugs used in treatment of acne that is antimicrobials. as you may already know the drugs of choice for this, are antibiotics. which block two consecutive steps in the biosynthesis cells for eventual production of dna, rna, and amino acids. other antibiotics include clindamycin,
Doxycycline, which disrupt bacterial ribosome to inhibit protein synthesis. for more detailed explanation of these and now, when it comes to side effects, if antibiotic on the other hand if antibiotic is applied now, unfortunately overuse of antibiotics to limit the resistance, topical agent called so benzoyl peroxide reduces the likelihood its unique mechanism of action,
Which involves since p. acnes bacteria cannot survive in in addition to its antimicrobial properties, benzoyl peroxide appears to have an anti-inflammatory when it comes to side effects, because benzoyl complaints are similar to other topical acne treatments and include dryness, redness, itching, and burning. used in treatment of acne that is hormonal therapy. and sebum
Production play a central role in acne formation. majority of the circulating androgens are however they are also produced locally by now, sebum production is mainly regulated by dehydroepiandrosterone-sulfate although dhea-s is considered a weak androgen, it into stronger androgens, starting with despite their formation within the sebocytes, these androgens can also be
Absorbed from the outside. once inside the cell, testosterone and dihydrotestosterone which then enters the nucleus and binds to that lead to sebocyte proliferation and enhanced sebum excretion. this can lead to overstimulation of androgen sebum production, subsequent clogging of the now, to mitigate this problem, agent called to block the androgen receptors within sebocytes
And thus inhibit androgen-induced sebocyte proliferation. in females, such as those relating to menstrual the main culprit in this case appears to be leads to increased testosterone to estrogen ratios during specific segments of the menstrual cycle. in addition to that, estrogen increases production which is a protein that regulates certain hormones including testosterone
And dihydrotestosterone, so another option for treating hormonal acne cycle with the use of oral contraceptives that work by few different mechanisms. hormone-binding globulin thereby decreasing levels of free testosterone. which in turn decreases androgen synthesis by the ovaries. and lastly, oral contraceptives inhibit 5α-reductase, of testosterone to the most potent
And active androgen, dihydrotestosterone. estradiol, combined with differing progestin components. it’s prudent to select oral contraceptive now, when it comes to side effects, spironolactone on the other hand, side effects of oral contraceptives breakthrough bleeding, weight gain and increased risk of blood clots. i hope you enjoyed this video, and as always, stay tuned for more.
Transcribed from video
Pharmacology – ACNE TREATMENTS (MADE EASY) By Speed Pharmacology
