Skip to main content

Clinical Trial Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

Clinical Trials in Hypogonadal Men

Table 2 shows the incidence of all adverse events judged by the investigator to be at least possibly related to treatment with AndroGel 1% and reported by > 1% of patients in a 180 Day, Phase 3 study.

Table 2: Adverse Events Possibly, Probably or Definitely Related to Use of AndroGel 1% in the 180-Day Controlled Clinical Trial

Adverse Event Dose of AndroGel 1%
50 mg
N = 77
75 mg
N = 40
100 mg
N = 78
Acne 1% 3% 8%
Alopecia 1% 0% 1%
Application Site Reaction 5% 3% 4%
Asthenia 0% 3% 1%
Depression 1% 0% 1%
Emotional Lability 0% 3% 3%
Gynecomastia 1% 0% 3%
Headache 4% 3% 0%
Hypertension 3% 0% 3%
Lab Test Abnormal* 6% 5% 3%
Libido Decreased 0% 3% 1%
Nervousness 0% 3% 1%
Pain Breast 1% 3% 1%
Prostate Disorder** 3% 3% 5%
Testis Disorder*** 3% 0% 0%
*Lab test abnormal occurred in nine patients with one or more of the following events reported: elevated hemoglobin or hematocrit, hyperlipidemia, elevated triglycerides, hypokalemia, decreased HDL, elevated glucose, elevated creatinine, elevated total bilirubin.
**Prostate disorders included five patients with enlarged prostate, one with BPH, and one with elevated PSA results.
***Testis disorders were reported in two patients: one with left varicocele and one with slight sensitivity of left testis.

Other less common adverse reactions, reported in fewer than 1% of patients included: amnesia, anxiety, discolored hair, dizziness, dry skin, hirsutism, hostility, impaired urination, paresthesia, penis disorder, peripheral edema, sweating, and vasodilation.

In this 180 day clinical trial, skin reactions at the site of application were reported with AndroGel 1%, but none was severe enough to require treatment or discontinuation of drug.

Six patients (4%) in this trial had adverse events that led to discontinuation of AndroGel 1%. These events included: cerebral hemorrhage, convulsion (neither of which were considered related to AndroGel 1% administration), depression, sadness, memory loss, elevated prostate specific antigen, and hypertension. No AndroGel 1% patient discontinued due to skin reactions.

In a separate uncontrolled pharmacokinetic study of 10 patients, two had adverse events associated with AndroGel 1%; these were asthenia and depression in one patient and increased libido and hyperkinesia in the other.

In a 3 year, flexible dose, extension study, the incidence of all adverse events judged by the investigator to be at least possibly related to treatment with AndroGel 1% and reported by > 1% of patients is shown in Table 3.

Table 3: Adverse Events Possibly, Probably or Definitely Related to Use of AndroGel 1% in the 3 Year, Flexible Dose, Extension Study

Adverse Event Percent of Subjects
(N = 162)
Lab Test Abnormal+ 9.3
Skin dry 1.9
Application Site Reaction 5.6
Acne 3.1
Pruritus 1.9
Enlarged Prostate 11.7
Carcinoma of Prostate 1.2
Urinary Symptoms* 3.7
Testis Disorder** 1.9
Gynecomastia 2.5
Anemia 2.5
+Lab test abnormal occurred in 15 patients with one or more of the following events reported: elevated AST, elevated ALT, elevated testosterone, elevated hemoglobin or hematocrit, elevated cholesterol, elevated cholesterol/LDL ratio, elevated triglycerides, elevated HDL, elevated serum creatinine.
*Urinary symptoms included nocturia, urinary hesitancy, urinary incontinence, urinary retention, urinary urgency and weak urinary stream.
**Testis disorders included three patients. There were two with a non-palpable testis and one with slight right testicular tenderness.

Two patients reported serious adverse events considered possibly related to treatment: deep vein thrombosis (DVT) and prostate disorder requiring a transurethral resection of the prostate (TURP).

Discontinuation for adverse events in this study included: two patients with application site reactions, one with kidney failure, and five with prostate disorders (including increase in serum PSA in 4 patients, and increase in PSA with prostate enlargement in a fifth patient).

Increases in Serum PSA Observed in Clinical Trials of Hypogonadal Men

During the initial 6-month study, the mean change in PSA values had a statistically significant increase of 0.26 ng/mL. Serum PSA was measured every 6 months thereafter in the 162 hypogonadal men on AndroGel 1% in the 3-year extension study. There was no additional statistically significant increase observed in mean PSA from 6 months through 36 months. However, there were increases in serum PSA observed in approximately 18% of individual patients. The overall mean change from baseline in serum PSA values for the entire group from month 6 to 36 was 0.11 ng/mL.

Twenty-nine patients (18%) met the per-protocol criterion for increase in serum PSA, defined as > 2X the baseline or any single serum PSA > 6 ng/mL. Most of these (25/29) met this criterion by at least doubling of their PSA from baseline. In most cases where PSA at least doubled (22/25), the maximum serum PSA value was still < 2 ng/mL. The first occurrence of a pre-specified, post-baseline increase in serum PSA was seen at or prior to Month 12 in most of the patients who met this criterion (23 of 29; 79%).

Four patients met this criterion by having a serum PSA > 6 ng/mL and in these, maximum serum PSA values were 6.2 ng/mL, 6.6 ng/mL, 6.7 ng/mL, and 10.7 ng/mL. In two of these patients, prostate cancer was detected on biopsy. The first patient's PSA levels were 4.7 ng/mL and 6.2 ng/mL at baseline and at Month 6/Final, respectively. The second patient's PSA levels were 4.2 ng/mL, 5.2 ng/mL, 5.8 ng/mL, and 6.6 ng/mL at baseline, Month 6, Month 12, and Final, respectively.

Postmarketing Experience

The following adverse reactions have been identified during post approval use of AndroGel 1%. Because the reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure (Table 4).

Table 4: Adverse Drug Reactions from Postmarketing Experience of AndroGel 1% by MedDRA System Organ Class

Blood and the lymphatic system disorders: Elevated Hgb, Hct (polycythemia)
Endocrine disorders: Hirsutism
Gastrointestinal disorders: Nausea
General disorders and administration site reactions: Asthenia, edema, malaise
Genitourinary disorders: Impaired urination
Hepatobiliary disorders: Abnormal liver function tests (e.g. transaminases, elevated GGTP, bilirubin)
Investigations: Elevated PSA, electrolyte changes (nitrogen, calcium, potassium, phosphorus, sodium), changes in serum lipids (hyperlipidemia, elevated triglycerides, decreased HDL), impaired glucose tolerance, fluctuating testosterone concentrations, weight increase
Neoplasms benign, malignant and unspecified (cysts and polyps): Prostate cancer
Nervous system: Headache, dizziness, sleep apnea, insomnia
Psychiatric disorders: Depression, emotional lability, decreased libido, nervousness, hostility, amnesia, anxiety
Reproductive system and breast disorders: Gynecomastia, mastodynia, prostatic enlargement, testicular atrophy, oligospermia, priapism (frequent or prolonged erections)
Respiratory disorders: Dyspnea
Skin and subcutaneous tissue disorders: Acne, alopecia, application site reaction (pruritus, dry skin, erythema, rash, discolored hair, paresthesia), sweating
Vascular disorders: Hypertension, vasodilation (hot flushes), venous thromboembolism

Secondary Exposure to Testosterone in Children

Cases of secondary exposure to testosterone resulting in virilization of children have been reported in postmarket surveillance. Signs and symptoms of these reported cases have included enlargement of the clitoris (with surgical intervention) or the penis, development of pubic hair, increased erections and libido, aggressive behavior, and advanced bone age. In most cases with a reported outcome, these signs and symptoms were reported to have regressed with removal of the testosterone gel exposure. In a few cases, however, enlarged genitalia did not fully return to age appropriate normal size, and bone age remained modestly greater than chronological age. In some of the cases, direct contact with the sites of application on the skin of men using testosterone gel was reported. In at least one reported case, the reporter considered the possibility of secondary exposure from items such as the testosterone gel user's shirts and/or other fabric, such as towels and sheets [see WARNINGS AND PRECAUTIONS].