Androgenic Alopecia (Male-pattern baldness

1
Androgenic Alopecia (Male-pattern baldness
Common baldness)

• Commonest type of hair loss. May be a
  physiological process.
• Prevalence rate is almost 100 in certain races.
• Mode of inheritance unknown.

2
Pathophysiology

• Normally
• On the top Androgen-sensitive follicles
• On the sides and back of the scalp
  androgen-independent follicles
• In genetically predisposed individuals(Under
  Influence of Androgens)
• Terminal hair follicles are transformed into
  vellus.
• Shortened anagen and an increased telogen.
• Decreased growth of hair on the scalp as well as
  axilla

3
Role of DHT

• T converted to DHT with the help of 5
  ?-reductase.
• Persons with an inherited deficiency of type II5
  ?-reductase castrated prepubertal boys or
  eunuchs do not develop androgenic alopecia
• Under the influence of DHT, the terminal follicle
  is converted to a vellus follicle
• High concentrations of DHT seen in the scalp of
  patients with androgenic alopecia.

4
Finasteride - Effects on semen production

• No effect since
• Testosterone is responsible for spermatogenesis
• Men with an inherited deficiency of 5 ?-reductase
  still have normal sperm development.

5
Pharmacokinetic properties of oral finasteride
after repeated administration of 1 mg/day or
after single dose of 5 mg.

• 1mg/day 5 mg (n12) (n6)

Day 1 Day 17 Cmax (?g/L) 6.5 9.2 38.1 tmax
(h) 1.6 1.3 1.8 t½ (h) 4.5 4.8 4.7 AUC0-24 (?g/L/h
) 38.2 53.2 180.6
6
Finasteride - 1mg

• Clinical Efficacy
• Evaluated in three phase III placebo-controlled
  studies, each of 1 years duration
• Additionally, the two studies in men with mild to
  moderate vertex hair loss continued in a blinded
  manner for a second year.
• A total of 1879 male patients aged between18 and
  41 years were enrolled in the trials.
• A wide spectrum of patients (vertex and frontal
  hair loss) were enrolled in the study.

7
Finasteride 1 MgIn Frontal Male Pattern Hair
Loss

• Double-blind placebo-controlled trial (n 326).
• End points included hair counts in the frontal
  scalp, patient self-assessment, investigator
  assessment and evaluation of global photographs.
• Finasteride 1 mg significantly increased scalp
  hair counts in the frontal area (Plt0.001).
• Cosmetic improvement was noted by patients,
  investigators and global reviewers.
• Aust J Dermatol 1997 38 (Suppl.2 ) 101-2

8
Finasteride-1 Mg Tolerability

• Not significantly different from that of placebo
  except for sexual functional disorders
• Sexual adverse events were reported in (3.8)
  finasteride compared with (2.1) placebo
  recipients and comprised decreased libido(1.8
  vs. 1.3), ejaculation disorders (1.2 vs. 0.7)
  and erectile dysfunction (1.3 vs. 0.7)
• Resolved in many patients who reported them but
  remained on therapy. It also resolved in those
  who stopped therapy.
• Small reductions (from 0.7 to 0.5 ng/ml) in serum
  prostate-specific antigen (PSA) may be seen.
  Hence double the reported PSA before interpreting.

9
Finasteride 1mg - Indications

• Treatment of men with male pattern hair loss and
  to prevent further hair loss in these patients.

10
Finasteride-1mg - Dosage Administration

• 1mg/day taken with or without food. Continue for
  at least 3 months before assessing. Effects are
  reversed within 12 months of stopping therapy
• Dosage adjustment unnecessary in elderly or in
  renal insufficiency.
• Contraindicated in women.

11
Patient 1
Baseline
Month 12
Month 24
J Am Acad Dermatol 1998 39578-89
12
Hair count mean change from baseline ( SE) from
the combined US and international studies for men
who entered the extension studies.
J Am Acad Dermatol 1998 39578-89
13
Investigator assessment mean rating score ( 1
SE) from the combined US and international
studies for men who entered the extension studies.
J Am Acad Dermatol 1998 39578-89
14
Treatment-related sexual adverse events reported
with finasteride. Men with male pattern hair loss
were randomised to receive oral finasteride 1
mg/day (n945) or placebo (n934) for 1 year.
p 0.041 vs. placebo
Drugs 1999 57(1) 111-126
15
Finasteride in frontal hair lossHair count mean
change from baseline ( 1 SE).
All patients 1 mg
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J Am Acad Dermatol 1999 40 930-7.