Καταρχήν σε ευχαριστώ για τα στοιχεία που παραθέτεις. Υπάρχουν μερικές μελέτες που αναφέρονται από τους σκεπτικιστές τις οποίες παραθέτω. Αυτή του 2011 που παρουσίασες είναι η χειρότερη στατιστικά αφού όπως αναφέρεις και εσύ, οι συμμετέχοντες ήταν μέλη του propeciahelp. Επίσης πρέπει να ξεκαθαρίσουμε ποιες μελέτες αναφέρονται στα 5mg και ποιές στο 1mg γιατί υπάρχει τεράστια διαφορά στην δοσολογία.
2015 Northwestern University Study
This study was essentially a review of 34 finasteride trials. It concluded that not one of those 34 published finasteride trials “provided adequate information about the severity, frequency or reversibility of sexually adverse effects.” Researchers found that adverse effects were not sufficiently graded in terms of their toxicity. According to the study’s lead author Dr. Steven Belknap,
“people who take or prescribe the drug assume it’s safe, but there is insufficient information to make that judgment.”
Potential Problem with this Study – The lead researchers received direct funding from the Post-Finasteride Syndrome Association.
2011 Journal of Sexual Medicine Survey
This study essentially went viral in 2011 and really put Propecia’s safety profile into question. It’s very controversial, primarily because the study’s lead researcher, Dr. Michael Irwig of George Washington University, recruited his subjects from an online Propecia support group. In other words,
the overwhelming majority of men involved in his survey were already having serious issues with the drug (or perhaps other, psychological problems). So while the statistics are somewhat shocking at face value, they’re really not all that surprising. Irwig found that:
- 94% suffered low libido
- 92% experienced erectile dysfunction
- 92% had decreased sexual arousal
- 69% developed problems with orgasm
- Side effects lasted an average of 40 months after treatment had been discontinued
Second 2015 Study
This study compared the safety of finasteride to tamsulosin; tamsulosin, like finasteride, is used to treat BPH and is a 5α-reductase inhibitor. The researchers in this study concluded that long-term finasteride use lowered testosterone levels and resulted in the worsening of ED symptoms. They also stated that ED symptoms did not worsen among patients who took tamsulosin.
Καμμία όμως από τις ανωτέρω μελέτες (πιθανώς και άλλες) δεν ήταν τόσο μεγάλης έκτασης και τόσο αναλυτικες όσο αυτές που έγιναν πριν την έγκριση του φαρμάκου για τον FDA. Παραθέτω παρακάτω μερικές από τις μελέτες για την μακροχρόνια χρήση φινας.
Five Year Propecia Study
This was perhaps the most significant, long-term study on Propecia. It was double-blinded, placebo-controlled, and involved 1,553 men. Hair counts, before-and-after photos, patient self-evaluations, and investigator assessments were all conducted as part of the study. The results were as follows:
- By the end of the fifth year, in a one-inch diameter area of the scalp, men on Propecia had an average 277 more hairs than the placebo group.
- 65% of the patients on Propecia either improved or maintained their hair counts compared to their counts at the start of the study.
- In their photo analyses, dermatologists found that 90% of the men on Propecia showed no further, visible hair loss at the study’s conclusion, compared to 25% in the placebo group.
- Overall satisfaction ratings were much higher in the treatment group than the placebo group — 63% to 20%, respectively. Men were treated with Propecia reported higher satisfaction with their hair’s appearance on their vertexes (59% vs. 13% on the placebo) and on their frontal hairlines (48 percent vs. 7 percent). Men in the Propecia group were also more likely to notice shrinking bald spots (61% vs. 20%), increased hair growth (75% vs. 40%) and a slower rate of hair loss (90% vs. 67%).
- Physician investigators found that 77% of patients on Propecia had increases in scalp hair, compared to 15% of patients in the placebo group (source).
- Side effects were rare. A few of the most common ones included less desire for sex (1.8% vs. 1.3% on placebo), difficulty in achieving an erection (1.3% vs. 0.7% on placebo), and a decrease in semen upon ejaculation (.8% vs .4%).
- All sexual side effects reportedly went away in men who discontinued treatment.
10-Year Study
This Italian study is the longest Propecia study I’m aware of. It tracked 118 men on Propecia for 10 years. The patients were evaluated at baseline and then after 1, 2, 5, and 10 years of treatment. This wasn’t a double-blinded or placebo controlled study. Here are a few of the pertinent results:
- After 10 years, only 14% patients experienced a worsening of hair loss.
- 86% benefited from the treatment, and its effectiveness was not found to diminish significantly over time in most of the patients.
- About 48% of the patients saw improvements over time.
- 7 subjects (5.9%) experienced side effects, and some of those patients stayed in the study because of the benefits they reported.
Prostate Cancer Prevention Trial (17,000+ Participants)
Finasteride is believed to lower the risk of certain types of prostate cancer, especially in older men. This
7-year study included over 17,000 participants. It was double-blinded and placebo-controlled. Researchers
used the study as an opportunity to evaluate the sexual side effects of finasteride. They utilized a comprehensive Sexual Activity Scale, ranging from 1 to 100; higher numbers indicated a higher degree of sexual dysfunction.
Keep in mind,
finasteride is typically prescribed at a much higher dosage for prostate cancer prevention (5 mg’s, vs. only 1 mg for hair loss).
In the study, researchers found:
- Finasteride increased sexual dysfunction only slightly in the control group, and that its effects diminished over time.
- The average Sexual Activity Scale score in the finasteride group was 3.21 points higher than the placebo group at the first assessment; It was only 2.11 points higher (again, on a 100 point scale) at the study’s conclusion.
- The researchers concluded that finasteride’s impact on sexual function is minimal in most men, and should therefore doctors should not alter their prescribing practices.
In a 2014 article, Meena K. Singh, MD and Marc Avram, MD state that this particular Prostate Cancer Prevention Study was
“the most informative trial specifically analyzing the effect of finasteride and sexual functioning” (
source). They conclude that based on the data of hundreds of controlled, randomized trials, finasteride should still be regarded as a safe and well-tolerated medication.
Αξίζει τον κόπο κάποιος να του ρίξει μια ματιά:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4285451/#B15
Ωραιές παραπομπές CVIAL, σε ευχαριστώ και εγώ με την σειρά μου.
Νομίζω,ότι δεδομένου του γεγονότος ότι δυστυχώς
υπάρχουν επίμονες διαταραχές στυτικής λειτουργίας αξίζει να ερευνηθούν και αυτές εώς δεδομένες.
Επίσης υπάρχουν και μελέτες που παράγουν αναφέρουν αντίθετες παρατηρήσεις από αυτές που παράθεσες.
Δες πχ
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4064044/
Αναφέρεται εδώ το εξής:
2. 5α-RIs therapy contributes to high Gleason grade PCa
The premise put forth by Huggins (1941) suggested that PCa is androgen-dependent and androgen deprivation results in tumor shrinkage [
56]. Androgen-dependency of PCa is predictable because tumor cells are derived from normal prostate cells, which retain expression of the androgen receptor (AR). Androgen deprivation therapy (ADT) of PCa
initially results in tumor regression, but the cancer often relapses into androgen-independent cancer within 18-24 months and tumors
no longer require androgens for growth [5,6]. ( τα bold και υπογραμμισμένα είναι δικές μου παρεμβάσεις στο κείμενο)
Όμως το πιο ανησυχητικό αναφέρεται λίγο πιο κατω και πιο συγκεκριμένα:
3. Potential adverse effects of 5α-R therapy on the CNS
The CNS has the capacity and the machinery to synthesize a host of neurosteroids [
72]. Neurosteroids play a pivotal role in modulating neural activity through interaction with neurotransmitter receptors and neurotransmitter-gaited ion-channels [
73]. These neurosteroids interact with a host of neurotransmitter receptors and modulate seizure susceptibility, anxiety, stress, and depression [
74]. 5α-R reaction is the rate limiting step in the conversion of testosterone, progesterone, cortisol, corticosterone, and DOC into their respective 5α-dihydro-deratitves, which serve as precursors for 3α-hydroxysteroid dehydrogenase which transfroms such precursors into their respective neurosteroids (androstanediol, allopregnanolone [AP], tetrahydrocortisol, tetrahdyrocorticosterone, and tetrahydrodeoxycorticosterone) (
Fig. 1) [
1,
2]. All three isoforms of 5α-R are expressed in the various regions of brain and are thought to be critical for brain development since fetal brain express high concentrations of 5α-R [
1,
2].
It has recently been shown that patients who had been treated with finasteride have reduced or undetectable levels of neuroactive steroids in their cerebro-spinal fluid and plasma, and exhibited higher levels of precursor steroids [
75]. This observation strongly suggests that 5α-RIs have a deleterious effect on the biosynthesis and function of neurosteroids in the central nervous system. Finasteride treatment resulted in decreased levels of 5α-DHT and 3α, 5α-tetrahydroprogesterone (AP) and increased levels of testosterone supporting the hypothesis that deleterious effects of finasteride may be persistent or irreversible. This may explain some of the noted symptoms such as anxiety, depression and suicide in patients who have been treated with finasteride [
76].
Στο ίδιο κείμενο, για όποιους έχουν την όρεξη να το διαβάσουν στην ολότητά του , εξηγείται και η αξία των νευροστεροειδών για την υγεία του ΚΝΣ αλλά και την σχέση τους με νευροεκφυλιστικές ασθένειες
NEUROPROTECTIVE EFFECTS OF NEUROSTEROIDS
Neuroactive steroids elicit important neuroprotective effects during trauma and injury to the central nervous system [
75]. AP is shown to be beneficial in the treatment of traumatic brain injury, attenuating edema, trauma, stress, inflammation, apoptosis, and reducing oxidative stress [
76,
77,
78]. AP is not only a protective agent in ischemia, but also in maintaining blood brain barrier integrity, and in memory and learning [
78,
79,
80,
81]. Studies on CNS injury in which asphyxiation was induced in fetal sheep to stimulate neurological stressors, in the presence or absence of finasteride, showed an increase in apoptotic cell death in the cerebellum and hippocampus in the animals treated with finasteride (
Fig. 5) [
82]. Furthermore, treatment with an AP analogue, alfaxalone, prevented cell death as assessed by the increase in activity of caspace-3 and expression of ki-67 protein.
This observation suggests that AP exerts a neuroprotective role in the brain, which is inhibited by finasteride.
Κλείνοντας θα ήθελα να τονίσω ότι αυτή η αντιπαράθεση κειμένων και ερευνών , από την πλευρά μου τουλάχιστον, δεν σκοπεύει να αποθαρρύνει πιθανούς χρήστες του φαρμάκου ,άλλωστε είμαι σίγουρος ότι για κάθε paper υπάρχει και τουλάχιστον ένα ,ίσης επιστημονικής εγκυρότητας, το οποίο το αναιρεί.
Δεν είμαι γιατρός, μηχανικός είμαι κι εγώ όπως ο CVIAL και για να είμαι ειλικρινής συμμετέχω σε αυτή την συγκεκριμένη συζήτηση λόγω πάθους για τις επιστήμες γενικά ,αλλά και για να καταθέσω την ταπεινή μου άποψη ότι στο θέμα των μακροχρόνιων παρενεργειών της φιναστερίδης και των άλλων αναστολέων της 5AR , the jury is still out.
