Testosterone Mechanism/Indications/PK

Question 1

What is the normal range for serum testosterone levels after testosterone replacement therapy?

Answer 1

The normal range is 300 to 1,100 ng/dL (10.4 to 38.2 nmol/L).

Question 2

What are the symptoms of hypogonadism that can be corrected by testosterone replacement therapy?

Answer 2

Symptoms include malaise, loss of muscle strength, depressed mood, and decreased libido.

Question 3

How does testosterone affect sexual drive?

Answer 3

Testosterone directly stimulates androgen receptors in the CNS, maintaining normal sexual drive.

Question 4

How does testosterone enhance the effects of phosphodiesterase type 5 in cavernosal tissue?

Answer 4

estosterone may stimulate nitric oxide synthase, increasing cavernosal concentrations of nitric oxide, enhancing phosphodiesterase type 5 effects.

Question 5

How does testosterone enhance relaxation and blood filling of the corpora cavernosa?

Answer 5

Testosterone downregulates RhoA/ROCK, a pathway responsible for calcium transport into penile smooth muscle cells, enhancing relaxation and blood filling.

Question 6

What is the typical threshold serum total testosterone level used to define hypogonadism?

Answer 6

Usually, a serum total testosterone less than 230 to 350 ng/dL (8.0 to 12.2 nmol/L) is used.

Question 7

When is it recommended to measure serum testosterone concentrations?

Answer 7

Typically in the early morning between 7 am and 11 am due to the circadian pattern of testosterone secretion.

Question 8

Who should not receive testosterone replacement regimens?

Answer 8

Men with normal serum testosterone levels, patients with asymptomatic hypogonadism, or patients with isolated erectile dysfunction as the only sign of hypogonadism.

Question 9

What improvements do testosterone replacement regimens promote in adult patients with hypogonadism?

Answer 9

They restore muscle strength, enhance sexual drive, support erythropoiesis, and improve mood, cognition, and bone density.

Question 10

How do testosterone replacement regimens impact erectile dysfunction?

Answer 10

They do not directly correct erectile dysfunction but improve libido, thus addressing secondary erectile dysfunction.

Question 11

When do observable clinical improvements typically occur after starting testosterone replacement?

Answer 11

Clinical improvements may take weeks to manifest after the start of testosterone replacement. For instance, increased libido may be evident at 6 weeks, while improvements in erectile dysfunction or muscle mass increase may take months.

Question 12

What is the minimum effective clinical trial duration for testosterone replacement regimens?

Answer 12

A minimum effective clinical trial is considered 3 to 6 months.

Question 13

Is there an additional benefit demonstrated for large doses of testosterone?

Answer 13

No, there is no additional benefit demonstrated for large doses of testosterone. Large doses that elevate testosterone to the upper end of the normal range or above-normal range do not show added benefits.

Question 14

What are the preferred modes of administration for testosterone replacement regimens?

Answer 14

Intramuscular injections of testosterone enanthate and cypionate, as well as subcutaneous implants of testosterone pellets, are preferred. Oral formulations are not recommended due to hepatotoxicity.

Question 15

How often do patients generally require dosing with intramuscular injections of testosterone enanthate or cypionate?

Answer 15

Patients generally require dosing every 2 to 4 weeks.

Question 16

What is a longer-acting intramuscular formulation of testosterone and how often can it be dosed?

Answer 16

Testosterone undecanoate is a longer-acting intramuscular formulation that can be dosed every 10 weeks.

Question 17

What adverse effects have been associated with testosterone undecanoate?

Answer 17

Testosterone undecanoate has been associated with pulmonary oil embolism and anaphylactic reactions that can necessitate hospitalization.

Question 18

Why are oral formulations of testosterone not recommended?

Answer 18

Oral formulations are associated with hepatotoxicity and are not recommended.

Question 19

What is a drawback of using testosterone patches, gels, and sprays?

Answer 19

They are much more expensive than injectable forms like testosterone enanthate or cypionate.

Question 20

What is a consideration regarding inadvertent transfer of testosterone with transdermal gel formulations?

Answer 20

Some transdermal gel formulations can inadvertently transfer testosterone to others.

Question 21

How often must the intranasal testosterone gel formulation be taken?

Answer 21

The intranasal formulation must be taken three times a day, which can be inconvenient.

Question 22

For whom are transdermal and nasal formulations of testosterone typically reserved?

Answer 22

ransdermal and nasal formulations should be reserved for patients who refuse injectable testosterone.

Question 23

What are the desired characteristics of the ideal testosterone replacement regimen?

Answer 23

The ideal regimen should mimic the normal circadian pattern of serum testosterone, maintain normal serum concentrations, mirror metabolites like dihydrotestosterone and estradiol, and have minimal adverse effects.

Question 24

What contributes to a high dropout rate in testosterone supplementation?

Answer 24

Factors contributing to a high dropout rate include medication cost, slow onset of response, and perceived inadequate benefit.

Question 25

Why are oral alkylated derivatives of testosterone not preferred for managing hypogonadism?

Answer 25

Oral alkylated derivatives of testosterone are not preferred due to a higher incidence of serious hepatotoxicity and the association with hepatotoxic effects.

Question 26

What is a concern associated with supraphysiologic serum testosterone levels produced by some testosterone formulations?

Answer 26

Supraphysiologic serum testosterone levels produced by certain formulations have been linked to mood swings and polycythemia in some patients.

Question 27

What is the typical duration of effect for intramuscular injections of testosterone undecanoate?

Answer 27

ntramuscular injections of testosterone undecanoate generally last for 10 weeks after the first and second doses, given 4 weeks apart.

Question 28

How long does the subcutaneous implant for testosterone replacement typically last before needing another dose?

Answer 28

A subcutaneous implant for testosterone replacement usually lasts 3 to 6 months before requiring another dose.

Question 29

In Androderm patches, where can they be applied for testosterone absorption?

Answer 29

Androderm patches can be applied to the upper arms, back, abdomen, or thighs for testosterone absorption.

Question 30

What precaution should be taken after applying a testosterone gel to prevent inadvertent transfer?

Answer 30

After applying a testosterone gel, the patient should wash hands thoroughly with soap and water, allow the application site to dry before covering, and ensure no contact with contaminated clothing by others.

Question 31

What is a characteristic of transdermal testosterone patches in terms of serum testosterone levels?

Answer 31

Transdermal testosterone patches increase serum testosterone levels to the normal range within 2 to 6 hours after application. The levels return to baseline 24 hours after patch administration

Question 32

How do transdermal testosterone patches or gel mimic natural hormone levels?

Answer 32

Transdermal testosterone patches, when applied at bedtime, or testosterone gel applied in the morning, produce physiologic patterns of serum testosterone levels throughout the day, resembling natural hormone levels.

Question 33

How is testosterone gel (1% formulation) typically applied in terms of dosage and application areas?

Answer 33

estosterone gel (1% formulation) is applied in larger doses (5 or 10 g each day) to the skin of the shoulders, upper arms, or abdomen.

Question 34

How quickly is testosterone absorbed when using the gel?

Answer 34

Testosterone from the gel is absorbed quickly, within 30 minutes of application, but complete absorption of the dose may take several hours.

Question 35

What precautions should be taken to prevent inadvertent transfer of testosterone gel to others?

Answer 35

Patients should wash their hands thoroughly with soap and water after gel application, allow the application site to dry for several minutes before dressing, and ensure that the gel does not come into contact with clothing that others, particularly children and female household members, might touch.