Testosterone-Based Health Conditions

What phase of the hair cycle is shortened in androgenetic alopecia?

Anagen phase.

What hormone is responsible for follicle miniaturization in AGA?

Dihydrotestosterone (DHT).

What enzyme converts testosterone to DHT?

5-alpha reductase.

What is the MOA of finasteride in AGA?

Inhibits 5-alpha reductase → ↓ DHT → prevents follicle miniaturization.

What is the dose of finasteride for AGA?

1 mg daily.

How long does it take to see full effect of finasteride?

~12 months

What is the MOA of minoxidil?

Vasodilation → ↑ blood flow → stimulates resting follicles.

How should minoxidil be applied?

Topically to the scalp BID.

How long before hair growth is seen with minoxidil?

4-8 months (max at 12-18 months).

What happens if minoxidil is discontinued?

Regrown hair is lost.

Common side effect of topical minoxidil?

Scalp irritation/dermatitis

Is combination therapy with minoxidil and finasteride more effective?

Yes

What two criteria must be met before starting testosterone therapy?

Low testosterone (confirmed) AND symptoms.

When should testosterone levels be measured?

Early morning (7-10 am)

Normal total testosterone range?

300-1000 ng/dL.

Name 3 specific symptoms of low testosterone.

Loss of body hair, gynecomastia, low sperm count.

Name 3 nonspecific symptoms of low testosterone.

↓ muscle mass, depressed mood, ↑ body fat.

What is a major hematologic risk of testosterone therapy?

Polycythemia

What cardiovascular effect can testosterone cause?

↑ BP (~6 mmHg).

How does testosterone affect fertility?

↓ spermatogenesis.

Absolute contraindication to testosterone therapy?

Prostate cancer.

Hematocrit level that contraindicates therapy?

> 52%

What is the risk of transdermal testosterone to others?

Secondary exposure (boxed warning).

How often should testosterone levels be monitored after stabilization?

Annually

When should gel testosterone levels be checked?

Prior to morning dose (trough).

When should injectable testosterone levels be checked?

Midpoint or trough between doses.

What symptom score is used to assess BPH severity?

IPSS (International Prostate Symptom Score).

Goal IPSS reduction with therapy?

≥3 point decrease.

First-line medication class for BPH?

Alpha blockers

MOA of alpha blockers?

Relax smooth muscle in bladder neck → improve urine flow.

Onset of action of alpha blockers?

4-6 weeks.

Common ADE of alpha blockers?

Orthostatic hypotension.

What is first-dose phenomenon?

Severe orthostatic hypotension after initial dose.

Which alpha blockers commonly cause ejaculatory dysfunction?

Tamsulosin and silodosin.

What serious ophthalmologic condition is associated with alpha blockers?

Intraoperative floppy iris syndrome.

MOA of 5-alpha reductase inhibitors in BPH?

Shrink prostate by ↓ DHT.

When are 5ARIs indicated?

Enlarged prostate (>30 cc or PSA >1.5).

Onset of action of 5ARIs?

3-6 months.

Do 5ARIs reduce prostate cancer risk?

↓ overall risk by 25% but ↑ high-grade cancer detection.

Which PDE-5 inhibitor is approved for BPH?

Tadalafil 5 mg daily

Recommended combination therapy for enlarged prostate?

Alpha blocker + 5ARI.

Is tadalafil + alpha blocker recommended?

No (↑ adverse effects).

Is saw palmetto recommended for BPH?

No

First-line pharmacologic therapy for ED?

PDE-5 inhibitors.

MOA of PDE-5 inhibitors?

Block breakdown of cGMP → prolonged vasodilation.

Do PDE-5 inhibitors require sexual stimulation?

Yes

Absolute contraindication to PDE-5 inhibitors?

Concomitant nitrate use.

Serious adverse effect requiring ER visit?

Priapism (>4 hours).

Rare vision complication of PDE-5 inhibitors?

NAION

Which PDE-5 inhibitor has the longest half-life?

Tadalafil (36 hours).

Which PDE-5 inhibitor has the fastest onset?

Avanafil

Which PDE-5 inhibitors are affected by high-fat meals?

Sildenafil and vardenafil.

How many doses are needed for an adequate PDE-5 trial?

5-8 doses

Second-line therapy after PDE-5 failure?

Alprostadil

MOA of alprostadil?

Prostaglandin E1 → smooth muscle relaxation → vasodilation.

First dose of alprostadil should be given where?

Under provider supervision.

What dose of finasteride is used for BPH?

5 mg

What dose of finasteride is used for alopecia?

1 mg

What lab must be monitored closely during testosterone therapy to prevent VTE risk?

Hematocrit

Which BPH drugs also treat hypertension?

Doxazosin and terazosin.

Which medications for ED also treat BPH?

Tadalafil