leggete e traducete, anche lei Doc!

[castano_chiaro]

 

Nell'altro forum si dice che il dr. Campo sembra molto ottimista su questo farlaco da usarsi in lozione, gli americani lo sono ancor di piu'! in anticipo vi dico pero' non vi illudete, non è stato approvato per la cura dell'aga. pertanto si fa per discuterne.

 

The first documentation of Latanoprost as a hair stimulant was in 1997 when a group of 43 patients were involved in the study. Researchers believe that Latanoprost has all the potentials to be a baldness treatment. Incidentally, Latanoprost (or Xalatan in U.S) is manufactured by Pharmacia & Upjohn, the same company who manufactures Rogaine, the #1 hair loss treatment in the world. It is unsure why Pharmacia & Upjohn never picked up on Latanoprost's hair stimulant properties. Some suggest that Pharmacia & Upjohn has no incentive to create any competition for its #1 selling hair loss treatment Rogaine. Why spend the time, money and go through the FDA regulatory red tapes once again when they are already the proud owner of the #1 selling hair loss tretment in the world ? The equation simply doesn't add up for Pharmacia & Upjohn. Another product out of Latanoprost would probably cannibalize the existing sales of Rogaine and the only thing to gain for Upjohn is the lost sales from Rogaine, a zero sum game !!

 

As of now, there is no clinical study to substantiate Latanoprost's effectiveness in growing hair on the scalp. No trials have been planned or initiated by any research groups yet. However, Latanoprost shares all the characteristics of minoxidil (Rogaine) and finasteride (Propecia) as a precursor for an effective hair loss treatment. If you recall, both Rogaine and Propecia were developed based on existing drugs that were formulated for different medical conditions. Rogaine was derived from the drug Loniten (minoxidil), an oral medication for patients with hypertension. Patients who were on Loniten repeatedly reported excessive body, facial and scalp hair growth as side effects. Upjohn leveraged on this side effect reported by Loniten patients and produced a blockbuster hit, ie: Rogaine, for hair loss. Similarly, Proscar (finasteride) was formulated for patients with benign prostate enlargement. Patients also reported hair growth as one of the side effects from Proscar. Merck did the same thing, capitalized on this finding and now manufactures the first ever oral medication for hair loss that rivals Rogaine. History repeats itself and hopefully, some pharmaceutical companies will capitalize on the potential of Latanoprost and offer hair loss sufferers a more potent alternative.

 

Latanoprost is also the perfect candidate to be the #1 underground treatment for hair loss. Just like the old days when Propecia was still in its embryonic stages, people read about what Proscar could do to hair growth and started a gold rush for the drug, despite the fact that Proscar was formulated for benign prostate enlargement and not for hair loss. Now Latanoprost makes an even better candidate. First, Latanoprost is an eyedrops so it would be easy for people to apply that topically to their scalp. Second, unlike Proscar which is an oral medication and may have serious side effects when taken orally, people may have less reservations using Latanoprost for hair loss since most topical treatments are less invasive to the body.

 

la fonte è

www.hairsite.com

[darko]

eh eh castà, l'argomento è stuzzicantissimo cxxxx!!! Dottore intervenga!!

Può entrarci qualcosa, visto l'effetto simil-prostaglandinico di cui si parla, il VEGF di cui si era tanto parlato all'inizio ma che poi è stato lasciato da parte? Glielo chiedo perchè so per certo che in America ci sono degli studi in atto a riguardo. Un'ultima cosa: qualche tempo fa aveva detto che qualcosa bolliva in pentola....tutto sfumato o la strada è vicina??

 

Grazie mille Dottore!

Modificato 26 Aprile 2006 da darko

[darko]

Prostaglandin analogs for hair growth: Great expectations

Ronni Wolf MD1, Hagit Matz MD1,2, Miriam Zalish3, Ayala Pollack MD3, Edith Orion MD1

Dermatology Online Journal 9(3): 7

 

1. The Dermatology Unit, Kaplan Medical Center, Rechovot 2. The Department of Dermatology, Tel-Aviv Sourasky Medical Center, Tel-Aviv 3. The Department of Ophthalmology, Kaplan Medical Center, Rechovot, Israel. [email protected]

 

 

 

 

 

Abstract

 

Latanoprost, a prostaglandin analog, has been reported to stimulate eyelash growth in patients using it in eye preparations for glaucoma and body and scalp hair growth when used topically in various animal models. Will prostaglandin analogs be the next agents used for forms of alopecia?

 

Shortly after the introduction of a prostaglandin analog, latanoprost (Xalatan®), as an intraocular pressure (IOP)-lowering drug for use in patients with glaucoma and ocular hypertension, the stimulating effect of this drug on eyebrow and eyelash hair growth and pigmentation was reported in an ophthalmology journal. [1] As when minoxidil appeared, physicians, researchers, pharmaceutical companies, and hair-challenged lay people the world over built up hopes that lightning had struck again and that latanoprost's hair-growing capabilities would be useful for treatment of baldness. Perhaps a family of similar chemicals would become new, effective hair-promoting drugs. Latanoprost is familiar to ophthalmologists colleagues because of its utility for the treatment of glaucoma, but dermatologists lag behind in understanding the effects of this new class of drugs. This paper is an update on this hot topic.

 

Clinical and observational studies

 

Latanoprost was first documented as a hair-growth stimulant by Johnstone in 1997. [1] Aware of this nonocular effect of the drug, he looked for evidence of hypertrichosis and pigmentation of eyelashes among 43 patients who were using unilateral topical latanoprost for glaucoma. Hypertrichosis was evaluated in the ipsilateral terminal and regional intermediate hairs of the upper and lower eyelids as well as vellus hair of the lower eyelid skin. There was a mean increase in lash length of the lower eyelid of 19.5 percent in the latanoprost-treated eye (range, 0%-36%). The two patients who had no measurable eyelash-length change exhibited an increase in the number of eyelashes. Differences in hair appearance between the latanoprost-treated eye and the nontreated control eye included increased number, length, thickness, curvature, and pigmentation.

 

Several additional case reports of hypertrichosis and darkening of eyelashes in patients treated with latanoprost have appeared. [2, 3, 4, 5, 6]. A representative case involved a 53-year-old woman who suffered from glaucoma and total loss of the eyelashes in both her eyes as well as diffuse scalp hair thinning after an allergic response to ibuprofen. She experienced a regrowth of all her eyelashes after 2 months of treatment with latanoprost.

 

Several subsequent studies that aimed to evaluate the effect of prostaglandin analogs on IOP also mention the side-effects of hypertrichosis and increased pigmentation of eyelashes. [7, 8, 9, 10, 11, 12, 13, 14]. In one study, changes in eyelash characteristics, including length, thickness, density, and color, were recorded in as many as 57 percent of treated patients. [13]

 

Three recent controlled studies that were specifically designed to evaluate quantitatively the apparent eyelash-lengthening effect of latanoprost yielded contradictory results. In one of them, seventeen patients with glaucoma or ocular hypertension were treated with latanoprost in one eye. [15] The mean eyelash length for the treated eye was 5.8 mm at baseline, 6.5 mm at 2 weeks, 6.5 mm at 6 weeks, and 6.6 mm at 10 weeks. The corresponding differences for the untreated eyes were nonsignificant (5.7 mm, 5.8 mm, 5.9 mm, and 5.6 mm, respectively). The authors' conclusion was that latanoprost significantly increases eyelash length. In a modest prospective study of seven patients treated with latanoprost for a minimum of 5 months, lash length was assessed using a digital imaging technique. [16] Only one patient showed longer lashes, and there were thicker lashes in ten of the fourteen examined eyes. In the third analysis, 44 patients affected by IOP were divided into two groups, one treated with latanoprost and the other with timolol (control group).[17] Although the latanoprost-treated patients showed a slight tendency toward an increase in eyelash length (mean of 0.2 mm) at the 6-month checkup, this effect was not statistically significant; it was aesthetically evident in only 7 percent of the treated subjects.

 

Finally, even the most ardent supporters of the hair-growth potential of PG analogs would probably agree that the results of Johnstone's study, [18] presented at the annual meeting of the Association for Research in Vision and Ophthalmology in 1998 were very unexpected and simply too good to be true. In reviewing the records and photographs of 89 glaucoma patients with hypertrichosis following unilateral treatment with topical latanoprost, he found five patients who had been treated for only a brief interval (less than 3 weeks) who showed increased number, length, thickness, and pigmentation of lashes similar to others who had undergone sustained treatment. Furthermore, these changes persisted in varying degrees for up to 14 months, the duration of the followup interval.

 

Experimental studies

 

Perhaps the most relevant study on the effect of latanoprost on scalp hair growth is the one by Uno et al. who used a macaque model of androgenetic alopecia. [19] The results of this well-controlled study (8 monkeys, 4 treated and 4 serving as controls) showed that treatment with 50 mcg/ml latanoprost daily over 5 months caused minimal hair growth, whereas 500 mcg/ml daily over 3 months induced moderate-to-marked hair regrowth. A 5-10 percent rate of conversion of vellus hairs to intermediary or terminal hairs was observed. The vehicle group showed no effect. Stjernschantz found a significant hypertrichotic effect of a selective prostanoid receptor agonist (fluprostenol) on hair growth as determined by measuring the rate of the regrowth of fur in adult male CBA-J mice.[20]

 

Speculating that activation of prostaglandin-H synthase (PGHS)-1 might be the mechanism by which minoxidil stimulates hair growth in vivo, Michelet et al. demonstrated that minoxidil is indeed a potent activator of purified PGHS-1, by assaying oxygen consumption and prostaglandin (PG)E2 production.[21] This activation was also evidenced by increased PGE2 production by BALB/c 3T3 fibroblasts and by human dermal papilla fibroblasts in culture. These findings suggest that the mechanism behind the hair-growth-stimulating effect of minoxidil is stimulation of PGE2 synthesis. If this conclusion were the case, it would stand to reason that other, more specific, PG activators (PG analogs) might show even better results.

 

Several studies performed before the introduction of prostaglandin analogs for the treatment of IOP showed that both systemic and topical application of PGE2 resulted in a significant degree of protection against radiation-, [22, 23, 24] or doxorubicin-induced [23] alopecia.

 

In a more recent study, prostaglandin receptor (EP)3 and EP4 mRNA were expressed in the dermal papilla cells and the outer-root-sheath cells located in the hair bulb region, respectively, in 3-week-old mouse dorsal skin (in the anagen phase). [25] In 8-week hair follicles (in the telogen phase), the signals for both EP3 and EP4 mRNA had disappeared. On days 8 and 12 after depilation, EP3 and EP4 mRNA were reexpressed, and induction of cyclooxygenase (COX)-2 mRNA was also observed, suggesting that PG receptors are involved in the development and regrowth of the hair follicles. [25]

 

Two studies [26, 27] using transgenic mice with overexpression of COX-2 in the skin showed directly contradictory results. Transgenic mice under the control of a bovine keratin 5 (K5) promoter[26] and human keratin 14 promoter[27] and overexpressing COX-2 in both the basal cells of the interfollicular epidermis and the pilosebaceous unit, exhibited reduced hair-follicle density and delayed postnatal hair follicle morphogenesis compared with wild-type animals. Administration of a specific COX-2 inhibitor (in one experiment [27]) restored hair growth, indicating that the alopecia was attributable to elevated COX-2 enzymatic activity.

 

Our prediction for the future

 

Although "it's tough to make predictions, especially about the future" (Yogi Berra of baseball fame), and although physicians and scientists find it hazardous to peer into a crystal ball, we are game to accept the challenge.

 

Even though scalp hair follicles and eyelash follicles are not identical, and one cannot simply extrapolate from a drug's effect on one type of hair to another, we believe that a powerful hair stimulant that acts on one type of hair should act on other types as well. Several of the above-mentioned experimental studies support the stimulating effects of PG analogs on hairs other than eyelashes (i.e., scalp hair and body fur). Furthermore, if the proposed mechanism of minoxidil action is indeed through its stimulating effect of PGE2 synthesis, then one should ask why we need to stimulate the synthesis of PG if we can use it directly? Minoxidil (which has been used by women to thicken their eyelashes and to treat alopecia areata of this area) showed inferior results on eyelash growth than those described for latanoprost. Minoxidil and finasteride must be used continuously to sustain results, and, once discontinued, the natural balding process resumes. PG analogs have a much more powerful and longer-lasting effect.[18]

 

Although we do not think that PG analogs are likely to emerge as the panacea for androgenetic alopecia, we strongly believe that they are excellent candidates to become the first drugs of choice for this affliction by achieving greater therapeutic success than other currently available preparations. Because it is highly unlikely that dermatologists encounter the effect of eyedrops on eyelash growth, and because most of the relevant literature appears in ophthalmological journals, most dermatologists know all too little about the promising effects of these new drugs. We hope that this attempt to enlighten our colleagues about these findings stimulates new lines of investigation that will reliably stimulate new and lasting hair growth.

Modificato 26 Aprile 2006 da darko

[Gigli]

Ha un suo razionale d'uso solo nelle alopecie areate del ciglio, non e' una novita .Per il resto da valutare.

saluìti

[Sylvius]

la sfxxx è che cmq costa una barca di soldi, già in passato era stato nominato sto prodotto

[darko]

Ma fosse solo quella la sfxxx!! Cmq ho contattato l'autore dell'articolo perchè mi sembra l'unica strada da perseguire ad oggi...vediamo se mi risponde l'israeliano!!

[castano_chiaro]

Grazie dottore, altre 3 domande

 

1) ma l'articolo la mette a paragone col Moinoxidil al 5% dicendo che è addiruttura meglio! evidentemente ha capacità di agire posivamente sulla inversione della miniaturizzazione follicolare visto che il sito parla di sides inesistenti rispetto ai farmaci ad uso orale (propecia).

 

le chiedo inoltre

2) ci sono possibili azioni nella stimolazione del TE cronico e sulla miglioria di capellini rimpiccioliti dal TE Cronico?

 

3) se lo metto sulle sopracciglia le infoltisce?

 

grazie

Modificato 27 Aprile 2006 da castano_chiaro

[Gigli]

1) non c'e alcuna base scientifica nell'afffermazione, anzi l'articolo afferma semmai che c'e una similitudine nel meccanismo d'azione

2) non saprei risponderti

3) potenzialmente si.

saluti

[castano_chiaro]

grazie infinite pero' a questo punto è obbligatoria una domanda, facciamo 2 dottore:

 

1) se lei dice che infoltisce probabilmente le sopracciaglia vuol dire che da vita a nuovi follicoli piliferi! infoltire = aumento di follicoli allora?

 

2) lei ha parlato di possibile mofica della pigmentazione, cosa intendeva dire?

 

grazie ancora.

[Francesco 22]

Usaa a percentuali minori può essere una nuova arma in più per la fase anagen!!

[Gigli]

Avendo similitudine di azione con il minoxidil puo' farlo, come effeto colaterakle puo' dare pigmentazioni della cornea,.

saluti

[darko]

I have suggested it to the two firms that produce the drug, and wanted them to supply me the stuff for treatment of vitiligo, alopecia areata, and androgenetic alopecia. They didn't respond.

 

Arrivederci,

 

Ronni

__________________________

Ronni Wolf, MD

Assoc. Clin. Prof. of Dermatology

Head, Dermatology Unit

Kaplan Medical Center

Rechovot 76100 Israel

 

La risposta eloquente alla mia domanda circa un potenziale utilizzo del principio attivo come nuovo trattamento anti-alopecia!! Cmq cerco di "spulciargli" qualche dettaglio che ci può essere utile.

 

ciao

[darko]

Cmq gli chiederò molto sulle nuove prospettive, visto che fa ricerca ad alto livello e vista la sua gentilezza e prontezza nel rispondere ad un perfetto sconosciuto, e vi farò sapere!!

 

dottore, perchè manca la base scientifica???

Modificato 27 Aprile 2006 da darko

[Sylvius]

ma chi sarebbe sto doc? uno che sta sperimentando il farmaco?

[castano_chiaro]

beh se avessi aga con diradamento evidente io personalmente lo proverei, tanto che sides ha a livello cuteneo? mi pare nessuno.

[Sylvius]

ok castà, ma a che dosi lo useresti?