In a controlled clinical study, 304 patients were treated with Testim® 50 mg or 100 mg or placebo gel for up to 90 days. Two hundred-five (205) patients received Testim® 50 mg or 100 mg daily and 99 patients received placebo. Patients with adverse events that were possibly or probably related to study drug and reported by ≥ 1% of the Testim® patients and greater than placebo are listed in Table 3.

Table 3: Incidence of Adverse Events Judged Possibly, Probably or Definitely Related to Use of Testim® in the Controlled Clinical Trial

The following adverse events possibly or probably related to Testim® occurred in fewer than 1% of patients but were greater in Testim® groups compared to the placebo group: activated partial thromboplastin time prolonged, blood creatinine increased, prothrombin time prolonged, appetite increased, sensitive nipples, and acne.

In this clinical trial of Testim®, six patients had adverse events that led to their discontinuation. These events included: vertigo, coronary artery disease, depression with suicidal ideation, urinary tract infection/pneumonia (none of which were considered related to Testim® administration), mood swings and hypertension. No Testim® patients discontinued due to skin reaction.

In one foreign Phase 3 trial, one subject discontinued due to a skin-related adverse event. In the pivotal U.S. and European Phase 3 trials combined, at the 50 mg dosage strength, the percentage of subjects reporting clinically notable increases in hematocrit or hemoglobin were similar to placebo. However, in the 100 mg dose group, 2.3% and 2.8% of patients had a clinically notable increase in hemoglobin ( ≥ 19 gm/dL) or hematocrit ( ≥ 58%), respectively.

In the combined ongoing U.S. and European open label extension studies, approximately 140 patients received Testim® for at least 6 months. The preliminary results from these studies are consistent with those reported for the U.S. controlled clinical trial.

Postmarketing Experience

The following adverse reactions have been identified during post-approval use of testosterone gel products. 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.

Secondary Exposure to Testosterone in Children

Cases of secondary exposure to testosterone resulting in virilization of children have been reported in postmarketing surveillance of testosterone gel products. Signs and symptoms of these reported cases have included enlargement of the clitoris (with surgical intervention) or of 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 fabrics, such as towels and sheets (see WARNINGS).

Drug Abuse And Dependence

Testim® contains testosterone, a Schedule III controlled substance as defined by the Anabolic Steroids Control Act. Oral ingestion of Testim® will not result in clinically significant serum testosterone concentrations due to extensive first-pass metabolism.

Read the Testim (testosterone gel) Side Effects Center for a complete guide to possible side effects »

Oxyphenbutazone: Concurrent administration of oxyphenbutazone and androgens may result in elevated serum levels of oxyphenbutazone.

Insulin: In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, insulin requirements.

Propranolol: In a published pharmacokinetic study of an injectable testosterone product, administration of testosterone cypionate led to an increased clearance of propranolol in the majority of men tested. It is unknown if this would apply to Testim®.

Corticosteroids: The concurrent administration of testosterone with ACTH or corticosteroids may enhance edema formation; thus these drugs should be administered cautiously, particularly in patients with cardiac or hepatic disease.

Drug/Laboratory Test Interactions

Androgens may decrease levels of thyroxin-binding globulin, resulting in decreased total T4 serum levels and increased resin uptake of T3 and T4. Free thyroid hormone levels remain unchanged, however, and there is no clinical evidence of thyroid dysfunction.

Last reviewed on RxList: 12/19/2011
This monograph has been modified to include the generic and brand name in many instances.