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53-422: The scalp is the anatomical area bordered by the face anteriorly and the neck to the sides and posteriorly. Scalp or SCALP may also refer to: Scalp The scalp is usually described as having five layers, which can be remembered using the mnemonic 'SCALP': The blood supply of the scalp is via five pairs of arteries, three from the external carotid and two from the internal carotid : Because

106-466: A genetic mutation , causing deficiency of the 5α-reductase enzyme and male hormone dihydrotestosterone (DHT), which was found to have been the etiology behind abnormalities in male sexual development. Upon maturation, these individuals were observed to have smaller prostates which were underdeveloped, and were also observed to lack incidence of male pattern baldness. In 1975, copies of Imperato-McGinley's presentation were seen by P. Roy Vagelos , who

159-480: A 93% reduction in facial hirsutism and a 73% reduction of bodily hirsutism after 2 years of treatment. Other studies using finasteride for hirsutism have also found it to be effective. Finasteride is sometimes used in hormone replacement therapy for transgender women due to its antiandrogenic effects, in combination with a form of estrogen . However, little clinical research of finasteride use for this purpose has been conducted and evidence of safety or efficacy

212-621: A conference on birth defects. She reported on a group of intersex children in the Caribbean who appeared sexually ambiguous at birth, and were initially raised as girls, but then grew external male genitalia and other masculine characteristic after onset of puberty. These children, despite being raised as girls until puberty, were generally heterosexual, and were termed " Guevedoces " by their local community, which means "penis at twelve" in Spanish. Her research group found these children shared

265-409: A mean age of 62.4) are at increased risk for impotence, erectile dysfunction (ED), decreased libido, and ejaculation disorder for the first year of treatment. The rates became indistinguishable from placebo after 2–4 years and these side effects usually got better over time. Finasteride may cause persistent adverse sexual, neurological and physical effects in a subset of men. A 2019 metastudy surveyed

318-402: A potent 5α-reductase inhibitor but a weak inhibitor of 5β-reductase, the medication decreases circulating levels of 5α-reduced steroids like allopregnanolone but does not reduce concentrations of 5β-reduced steroids like pregnanolone . Pregnanolone acts as a potent GABA A receptor positive allosteric modulator similarly to allopregnanolone. The mean oral bioavailability of finasteride

371-921: A proposed post-finasteride syndrome (PFS), although some within the medical community question whether there is enough evidence to support a causal relationship between finasteride usage and PFS. Individuals claiming to experience PFS report sexual, neurological, hormonal and psychological side effects that persist for an extended period after stopping the drug. Reported symptoms include penile atrophy and tissue changes, decreased ejaculate volume and quality, reduced libido, erectile dysfunction, loss of penile sensitivity, decreased orgasm sensation, dry skin, metabolic changes, muscle and strength loss, gynecomastia , depression, anxiety, panic attacks, insomnia, anhedonia , concentration problems, memory impairment and suicidal ideation . A meta-analysis found significant association between finasteride use and post-discontinuation depression, suicidal ideation, and sexual dysfunction, but

424-441: A “danger zone” though. The clinically important layer is the aponeurosis. Scalp lacerations through this layer mean that the "anchoring" of the superficial layers is lost and gaping of the wound occurs which would require suturing. This can be achieved with simple or vertical mattress sutures using a non-absorbable material, which are subsequently removed at around days 7–10. All the current hair transplantation techniques utilize

477-481: Is 76 L. Its plasma protein binding is 90%. The drug has been found to cross the blood–brain barrier , whereas levels in semen were found to be undetectable. Finasteride is extensively metabolized in the liver , first by hydroxylation via CYP3A4 and then by aldehyde dehydrogenase . It has two major metabolites , which are the tert - butyl side chain monohydroxylated and monocarboxylic acid metabolites. These metabolites show approximately 20% of

530-492: Is a synthetic androstane steroid and 4-azasteroid . It is an analogue of androgen steroid hormones like testosterone and DHT. As an unconjugated steroid, finasteride is a highly lipophilic compound. In 1942, James Hamilton observed that prepubertal castration prevents the later development of male pattern baldness in mature men. In 1974, Julianne Imperato-McGinley of Cornell Medical College in New York attended

583-494: Is approximately 65%. The absorption of finasteride is not affected by food. At steady-state with 1 mg/day finasteride, mean peak concentrations of finasteride were 9.2 ng/mL (25 nmol/L). Conversely, following a single 5 mg dose of finasteride, mean peak levels of finasteride were 37 ng/mL (99 nmol/L), and plasma concentrations increased by 47–54% following 2.5 weeks of continued daily administration. The volume of distribution of finasteride

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636-537: Is its DCF Tooltip Dénomination Commune Française . It is also known by its former developmental code names MK-906 , YM-152 , and L-652,931 . Finasteride is marketed primarily under the brand names Propecia, for pattern hair loss, and Proscar, for BPH, both of which are products of Merck & Co . There is 1 mg of finasteride in Propecia and 5 mg in Proscar. Merck's patent on finasteride for

689-772: Is limited. Moreover, caution has been recommended when prescribing finasteride to transgender women, as finasteride may be associated with side effects such as depression, anxiety, and suicidal ideation, symptoms that are particularly prevalent in the transgender population and in others at high risk already. A 2010 Cochrane review of finasteride for BPH found that, in men with a weighted mean age of 62.4, adverse effects are rare in men with already enlarged prostates; “nevertheless, men taking finasteride are at increased risk for impotence, erectile dysfunction, decreased libido, and ejaculation disorder, versus placebo." As of 2016 , fresh evidence suggested such effects, along with disturbed neurosteroid production, may persist after finasteride use

742-813: Is low at about 1.5%. Depressive symptoms and suicidality have been reported. Use of finasteride is associated with an increased risk of sexual dysfunction including erectile dysfunction , decreased libido and ejaculatory dysfunction. Sexual adverse effects of finasteride and dutasteride have been linked to lower quality of life and ability to maintain an intimate relationship, and can cause stress in relationships. The adverse effect profiles of finasteride are somewhat different for its indications of hair loss and BPH. The most common adverse effects of finasteride taken for hair loss are: decrease in sex drive, erectile dysfunction and decrease in amount of semen. In addition, finasteride has been reported in case reports to cause sexual problems which persist after stopping

795-402: Is no specific recommended antidote for finasteride overdose. No significant drug interactions have been observed between finasteride and a limited selection of medications. Finasteride is a 5α-reductase inhibitor . It is specifically a selective inhibitor of the type II and III isoforms of the enzyme . By inhibiting these two isozymes of 5α-reductase, finasteride reduces

848-418: Is stopped. Finasteride is contraindicated in pregnancy. The Food and Drug Administration advises that donation of blood or plasma be deferred for at least one month after taking the last dose of finasteride. The FDA has added a warning to 5α-reductase inhibitors concerning an increased risk of high-grade prostate cancer , as the treatment of BPH lowers PSA ( prostate-specific antigen ), which could mask

901-483: Is the act of removing a human scalp, usually with hair, as a trophy . Often associated with the history of North America, scalping developed independently on multiple continents and dates back to antiquity. Finasteride Finasteride , sold under the brand names Proscar and Propecia among others, is a medication used to treat pattern hair loss and benign prostatic hyperplasia (BPH) in men. It can also be used to treat excessive hair growth in women. It

954-445: Is the one known as micro grafting because it produces naturalistic results. It is akin to follicular unit extraction , although less advanced. A knife with multiple blades is used to remove tissue from donor areas. The removed tissue is then fragmented into smaller chunks under direct vision inspection (i.e., without a microscope). The scalp is a common site for the development of tumours including: The scalp plays an important role in

1007-767: Is usually taken orally but there are topical formulations for patients with hair loss, designed to minimize systemic exposure by acting specifically on hair follicles. Finasteride is a 5α-reductase inhibitor and therefore an antiandrogen . It works by decreasing the production of dihydrotestosterone (DHT) by about 70%. In addition to DHT, finasteride also inhibits the production of several anticonvulsant neurosteroids including allopregnanolone , androstanediol , and tetrahydrodeoxycorticosterone . Adverse effects from finasteride are rare in men with already enlarged prostates; however, some men experience sexual dysfunction , depression , and breast enlargement . In some men, sexual dysfunction may persist after stopping

1060-537: The 5α-reductase type I isoenzyme, with more than 100-fold less inhibitory potency for type I as compared to type II ( IC 50 Tooltip Half-maximal inhibitory concentration = 313 nM and 11 nM, respectively). This is in contrast to inhibitors of all three isoenzymes of 5α-reductase like dutasteride , which can reduce DHT levels in the entire body by more than 99%. In addition to inhibiting 5α-reductase, finasteride has also been found to competitively inhibit 5β-reductase (AKR1D1). However, its affinity for

1113-417: The aesthetics of the face. Androgenic alopecia , or male pattern hair loss, is a common cause of concern to men. It may be treated with varying rates success by medication (e.g. finasteride , minoxidil ) or hair transplantation. If the scalp is heavy and loose, a common change with ageing , the forehead may be low, heavy and deeply lined. The brow lift procedure aims to address these concerns. Scalping

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1166-781: The androgen receptor . Finasteride results in a decrease of circulating DHT levels by about 65–70% with an oral dosage of 5 mg/day and of DHT levels in the prostate gland by up to 80–90% with an oral dosage of 1 or 5 mg/day. In parallel, circulating levels of testosterone increase by approximately 10%, while local concentrations of testosterone in the prostate gland increase by about 7-fold and local testosterone levels in hair follicles increase by around 27–53%. An oral dosage of finasteride of only 0.2 mg/day has been found to achieve near-maximal suppression of DHT levels (68.6% for 0.2 mg/day relative to 72.2% for 5 mg/day). Finasteride does not completely suppress DHT production because it lacks significant inhibitory effects on

1219-489: The amount of terminal hairs in the anagen phase by inhibiting and sometimes reversing miniaturization of the hair follicle. Finasteride is most effective on the crown but can reduce hair loss in all areas of the scalp. Finasteride has also been tested for pattern hair loss in women; however, the results were no better than placebo. Finasteride is less effective in the treatment of scalp hair loss than dutasteride . In males aged 55 years old and over finasteride decreases

1272-462: The anterior half drain to the parotid nodes. The lymph eventually reaches the submandibular and deep cervical nodes. The 'danger area of the scalp' is the area of loose connective tissue. This is because pus and blood spread easily within it, and can pass into the cranial cavity along the emissary veins. Therefore, infection can spread from the scalp to the meninges, which could lead to meningitis. further studies are needed to conclude that it’s actually

1325-409: The biomedical research community, have concluded based on the available evidence, that it represents a real and serious condition. There is no known underlying biological mechanism for the proposed syndrome, and its incidence is unclear. A lack of clear diagnostic criteria and the variable reporting fraction in different health-care settings make the problem challenging to evaluate. As of 2016, Merck

1378-488: The brand name Propecia. It was the first 5α-reductase inhibitor to be introduced and was followed by dutasteride in 2001. The first study of finasteride in the treatment of hirsutism in women was published in 1994. Finasteride is the generic name of the drug and its INN Tooltip International Nonproprietary Name , USAN Tooltip United States Adopted Name , BAN Tooltip British Approved Name , and JAN Tooltip Japanese Accepted Name , while finastéride

1431-616: The development of prostate cancer. Although overall incidence of male breast cancer in clinical trials for finasteride 5 mg was not increased, there are post-marketing reports of breast cancer in association with its use, though available evidence does not provide clarity as to whether there is a causative relationship between finasteride and these cancers. A 2018 meta-analysis found no higher risk of breast cancer with 5α-reductase inhibitors. Some men develop gynecomastia (breast development or enlargement) following finasteride usage. The risk of gynecomastia with 5α-reductase inhibitors

1484-709: The different isozymes of 5α-reductase appear to be widely expressed, with notable tissues including the prostate gland, seminal vesicles , testes , epididymides , skin, hair follicles, liver , kidneys , and brain , among others. By inhibiting 5α-reductase and thus preventing DHT production, finasteride reduces androgen signaling in tissues like the prostate gland and the scalp. In the prostate, this reduces prostate volume, which improves BPH and reduces risk of prostate cancer. Finasteride reduces prostate volume by 20 to 30% in men with benign prostatic hyperplasia. Inhibition of 5α-reductase also reduces epididymal weight, and decreases motility and normal morphology of spermatozoa in

1537-469: The drug showed significant sexual adverse effects such as erectile dysfunction and less sexual desire, in particular when obstructive symptoms due to an enlarged prostate were present. Finasteride is also used to treat male pattern baldness (androgenic alopecia) in men, a condition that develops in up to 80% of Caucasian men aged 70 and over. In the United States, finasteride and minoxidil are

1590-501: The emissary vein and frontal diploic vein, which also contribute to the venous drainage. Innervation is the connection of nerves to the scalp: the sensory and motor nerves innervating the scalp. The scalp is innervated by the following: The innervation of scalp can be remembered using the mnemonic 'Z-GLASS' for Z ygomaticotemporal nerve, G reater occipital nerve, L esser occipital nerve, A uriculotemporal nerve, S upratrochlear nerve, and S upraorbital nerve. The motor innervation of

1643-417: The enzyme is substantially less than for 5α-reductase (an order of magnitude less than for 5α-reductase type I ) and hence is unlikely to be of clinical significance. As of 2012, the tissues in which the different isozymes of 5α-reductase are expressed are not fully clear. This is because different investigators have obtained varying results with different reagents , methods, and tissues examined. However,

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1696-582: The epididymis. Neurosteroids like 3α-androstanediol (derived from DHT) and allopregnanolone (derived from progesterone ) activate the GABA A receptor in the brain ; because finasteride prevents the formation of neurosteroids, it functions as a neurosteroidogenesis inhibitor and may contribute to a reduction of GABA A activity. Reduction of GABA A receptor activation by these neurosteroids has been implicated in depression , anxiety , and sexual dysfunction . In accordance with finasteride being

1749-419: The facial vein. The superficial temporal vein descends in front of the tragus, enters the parotid gland, and then joins the maxillary vein to form the retromandibular vein. The anterior part of it unites with the facial vein to form the common facial vein, which drains into jugular vein, and ultimately to the subclavian vein. The occipital vein terminates to the sub-occipital plexus. There are other veins, like

1802-437: The formation of the potent androgen dihydrotestosterone (DHT) from its precursor testosterone in certain tissues in the body such as the prostate gland , skin , and hair follicles . As such, finasteride is a type of antiandrogen , or more specifically, an androgen synthesis inhibitor . However, some authors do not define finasteride as an "antiandrogen," a term which can refer more specifically to antagonists of

1855-489: The inhibitory activity of finasteride on 5α-reductase. Hence, the metabolites of finasteride are not particularly active. The drug has a terminal half-life of 5 to 6 hours in adult men (18–60 years of age) and a terminal half-life of 8 hours or more in elderly men (more than 70 years of age). It is eliminated as its metabolites 57% in the feces and 40% in the urine . Finasteride, also known as 17β-( N -tert-butylcarbamoyl)-4-aza-5α-androst-1-en-3-one,

1908-450: The last dose of finasteride. The UK also has a one-month deferral period. Preliminary research suggests that topical finasteride may be effective in the treatment of pattern hair loss . Topical finasteride, like the oral preparation, reduces serum DHT. DHT may be involved in the cause of acne , and 5α-reductase inhibitors might be effective in the treatment of the condition. A small retrospective study reported that finasteride

1961-519: The literature on the reversibility of finasteride's side effects. It identified three studies which demonstrated full reversibility of side effects and eleven that describe patients with irreversible adverse events. The findings were most convincing in a retrospective review of about 12,000 patients that 1.4% of the cohort developed persistent ED (ED lasting longer than 90 days post-withdrawal). Reports of long-term, post-discontinuation adverse effects in some fraction of former finasteride users have led to

2014-621: The medication. A 2012 update to the FDA label noted reports of decreased sex drive, problems with ejaculation and difficulty achieving an erection which continued after stopping the medication. The update also referenced reports of testicular pain and "male infertility and/or poor quality of semen." The most common adverse sexual effects of finasteride for BPH are: trouble getting or keeping an erection, decrease in sex drive, decreased volume of ejaculate and ejaculation disorders. A 2010 Cochrane review found that men taking finasteride for BPH (with

2067-481: The medication. It may also hide the early symptoms of certain forms of prostate cancer . Finasteride was patented in 1984 and approved for medical use in 1992. It is available as a generic medication . In 2022, it was the 73rd most commonly prescribed medication in the United States, with more than 9   million prescriptions. Finasteride has been used for the treatment of symptomatic benign prostatic hyperplasia (BPH) in men with an enlarged prostate and for

2120-421: The only two FDA approved drugs for the treatment of male pattern hair loss as of 2017. Treatment with finasteride slows further hair loss and provides about 30% improvement in hair loss after six months of treatment, with effectiveness persisting as long as the drug is taken. Taking finasteride leads to a reduction in scalp and serum DHT levels; by lowering scalp levels of DHT, finasteride can maintain or increase

2173-494: The patient's existing hair. The aim of the surgical procedure is to use such hair as efficiently as possible. The right candidates for this type of surgery are individuals who still have healthy hair on the sides and the back of the head in order that hair for the transplant may be harvested from those areas. Different techniques are utilized in order to obtain the desired cosmetic results; factors considered may include hair color, texture, curliness, etc. The most utilized technique

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2226-465: The quality of evidence was limited. The status of PFS as a legitimate and distinct medical pathology remains a subject of debate. A 2019 editorial in The BMJ called post-finasteride syndrome "ill defined and controversial". Some have argued that it has common features with other self-diagnosed "mystery syndromes" such as Morgellons or multiple chemical sensitivity , while others, including some in

2279-478: The risk of developing certain rare but aggressive forms of prostate cancer (27% risk increase), although not all studies have observed this. No impact of 5-α-reductase inhibitor on survival has been found in people with prostate cancer. Finasteride has been found to be effective in the treatment of hirsutism (excessive facial and/or body hair growth) in women. In a study of 89 women with hyperandrogenism due to persistent adrenarche syndrome , finasteride produced

2332-553: The risk of low-grade prostate cancer but may increase the risk of high-grade prostate cancer and has no effect on overall survival. A 2010 review found a 25% reduction in the risk of prostate cancer with 5α-reductase inhibitor. A follow-up study of the Medicare claims of participants in a 10-year Prostate Cancer Prevention Trial suggests the reduction in prostate cancer is maintained even after discontinuation of treatment. However, 5α-reductase inhibitors have been found to increase

2385-423: The scalp, specifically, the occipitofrontalis muscle, is split into two main factions: the frontal belly or frontalis muscle is supplied by the temporal branch of facial nerve , while the occipital belly or occipitalis is supplied by the posterior auricular branch of facial nerve . Lymphatic channels from the posterior half of the scalp drain to occipital and posterior auricular nodes. Lymphatic channels from

2438-593: The treatment of BPH expired in June 2006. Merck was awarded a separate patent for the use of finasteride to treat pattern hair loss and it expired in November 2013. Finasteride is also marketed under a variety of other brand names throughout the world. From 2005 to 2009, the World Anti-Doping Agency banned finasteride because it was discovered that the drug could be used to mask steroid abuse. It

2491-428: The treatment of male pattern hair loss (androgenetic alopecia) in men. Physicians sometimes prescribe finasteride for the treatment of benign prostatic hyperplasia, informally known as an enlarged prostate . Finasteride may improve the symptoms associated with BPH such as difficulty urinating, getting up during the night to urinate, hesitation at the start and end of urination, and decreased urinary flow. The use of

2544-438: The walls of the blood vessels are firmly attached to the fibrous tissue of the superficial fascial layer, cut ends of vessels here do not readily retract; even a small scalp wound may bleed profusely. Venous drainage The veins of the scalp accompany the arteries and thus have similar names, e.g. Supratrochlear and supraorbital veins, which unite at the medial angle of the eye, and form the angular vein, which further continues as

2597-814: Was a defendant in approximately 1,370 product liability lawsuits which had been filed by customers alleging they have experienced persistent sexual side effects following cessation of treatment with finasteride. Most cases were settled by 2018 when Merck paid a lump sum of US$ 4.3 million to be distributed. As of September 2019 , 25 cases remained outstanding in the United States. In 2019, Reuters reported that faulty redactions in court documents revealed allegations from plaintiffs that Merck had known of persistent side effects in their original clinical trials but chose not to disclose them in warning labels. Finasteride has been studied in humans at single doses of up to 400 mg and at continuous dosages of up to 80 mg/day for three months, without adverse effects observed. There

2650-467: Was approved by the U.S. Food and Drug Administration (FDA) for treatment of BPH, which Merck marketed under the brand name Proscar. Rasmusson and Brooks were awarded IPO's "Inventor of the Year" award in 1993 for their work on finasteride. In 1997, Merck was successful in obtaining FDA approval for a second indication of finasteride (1 mg) for treatment of male pattern hair loss, which was marketed under

2703-459: Was effective in the treatment of acne in women with normal testosterone levels. A randomized controlled trial found that finasteride was less effective than flutamide or an ethinylestradiol/cyproterone acetate birth control pill in the treatment of acne in women with high androgen levels . Androgens and estrogens may be involved in the cause of hidradenitis suppurativa (acne inversa). Two case series have reported that finasteride

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2756-465: Was removed from the list effective 1 January 2009, after improvements in testing methods made the ban unnecessary. Athletes who used finasteride and were banned from international competition include skeleton racer Zach Lund , bobsledder Sebastien Gattuso , footballer Romário , and ice hockey goaltender José Théodore . The US Food and Drug Administration advises that donation of blood or plasma be deferred for at least one month after taking

2809-628: Was then serving as Merck 's basic-research chief. He was intrigued by the notion that decreased levels of DHT led to the development of smaller prostates. Dr. Vagelos then sought to create a drug which could mimic the condition found in these children to treat older men who had benign prostatic hyperplasia. Finasteride was developed by Merck under the code name MK-906. A team led by chemist Gary Rasmusson and biologist Jerry Brooks developed potential 5α-reductase inhibitors based on transition state inhibitors, using an iterative process of molecular design, testing, and redesign. In 1992, finasteride (5 mg)

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