Testosterone enanthate

Name: Testosterone enanthate

Interactions for Testosterone Enanthate

Specific Drugs

Drug

Interaction

Comment

Anticoagulants, oral

Testosterone may potentiate the action of oral anticoagulantsa and decrease anticoagulant requirements117 133 162

Monitor INR and prothrombin time closely when androgen therapy is initiated or discontinued in patients receiving oral anticoagulants and adjust anticoagulant dosage as needed133 162 166 a

Corticotropin (ACTH) and corticosteroids

Increased risk of fluid retention and edema157 161 162 166

Use with caution, particularly in patients with cardiac, renal, and/or hepatic disease157 161 162 166

Monitor patients for fluid retention and edema133

Insulin

Testosterone may decrease blood glucose concentrations and, therefore, insulin requirements in patients with diabetes117 133 157 161 162 166

Changes in insulin sensitivity or glycemic control may occur in patients receiving androgens166

Propranolol

IM testosterone cypionate may increase clearance of propranolol.135 157 174 Not known whether topically administered testosterone gel has potential for this interaction135 157

Triamcinolone

Reduced testosterone absorption following topical application of triamcinolone ointment prior to application of testosterone transdermal system133

Testosterone absorption not altered following topical administration of 0.1% triamcinolone cream prior to application of testosterone transdermal system133

Oxyphenbutazone

Increased serum concentrations reported with concurrent androgen administration157

Advice to Patients

Pending revision, the material in this section should be considered in light of more recently available information in the MedWatch notification at the beginning of this monograph.

  • Risk of MI or stroke.133 175 Contact clinician if symptoms suggestive of MI or stroke (e.g., chest pain, shortness of breath, unilateral weakness, difficulty talking) occur.175

  • Risk of virilization in females.133 157 161 162 166 Advise female patients receiving testosterone therapy and female partners of patients treated with topical testosterone preparations (e.g., gel, transdermal systems) to contact their clinician if they notice changes in body hair distribution, substantial increases in acne, or other manifestations of virilization.117 133 157 161 162 166

  • Risk of virilization in children resulting from secondary exposure to testosterone.166 167 168 169 170 171 172 173 Contact clinician if inappropriate changes in genital size, development of pubic hair, increased erections and libido, or aggressive behavior occur in children when transfer of topically administered testosterone gel from another individual is possible.117 133 157 161 162 166

  • Importance of children and women avoiding contact with application sites on the skin of men using testosterone gel.170 171 If contact with unwashed or unclothed skin at the site of testosterone gel application occurs with the skin of another individual, importance of washing the general area of contact with soap and water as soon as possible.135 157 170 171

  • Importance of promptly discontinuing testosterone gel when virilization occurs in children or women in contact with men using testosterone gel products until the cause of virilization is identified.170 171

  • Risk of developing benign prostatic hyperplasia or prostate cancer.133 157 166 Importance of evaluating patients for prostate cancer, especially geriatric patients and those with clinical or demographic characteristics associated with increased risk, prior to initiating and during testosterone therapy.133 157 166

  • Importance of informing patients that changes in urinary habits may occur with testosterone therapy, including increased urinary frequency, urgency, incontinence, nocturia.133

  • Risk of priapism; importance of adult or adolescent males informing their clinician if too frequent or persistent penile erections occur.133

  • Importance of periodic assessments to determine the rate of bone maturation in prepubertal males receiving testosterone therapy for delayed puberty.161

  • Importance of patients informing their clinician of nausea, vomiting, changes in skin color, ankle swelling, or breathing disturbances (e.g., sleep apnea).117 133 135 157 161 162

  • Importance of instructing patients in the proper use (see Administration under Dosage and Administration) and disposal of testosterone preparations and of providing patients a copy of manufacturer’s patient information.133 135 157 161

  • Importance of advising patients receiving therapy with extended-release buccal tablets to regularly inspect the gum region where the tablet is applied and to report any abnormality to their clinician.161

  • For patients using gel preparations, importance of strictly adhering to the recommended instructions for use and precautions from the manufacturers.170 171

  • For patients using gel preparations, importance of washing hands immediately with soap and water following application of gel and covering the application site with clothing after allowing gel to dry.166 170

  • For patients using gel preparations, importance of avoiding fire, flames, and smoking until gel has dried.166

  • Importance of women informing their clinician if they are or plan to become pregnant or to breast-feed.117 133 135 157 161 162

  • Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs and herbal supplements, as well as any concomitant illnesses.117 133 135 157 161 162

  • Importance of informing patients of other important precautionary information.117 133 135 157 161 162 (See Cautions.)

Testosterone Enanthate - Clinical Pharmacology

Endogenous androgens are responsible for the normal growth and development of the male sex organs and for maintenance of secondary sex characteristics. These effects include growth and maturation of prostate, seminal vesicles, penis, and scrotum; development of male hair distribution, such as beard, pubic, chest, and axillary hair; laryngeal enlargement; vocal chord thickening; alterations in body musculature; and fat distribution.

Androgens also cause retention of nitrogen, sodium, potassium, and phosphorus, and decreased urinary excretion of calcium. Androgens have been reported to increase protein anabolism and decrease protein catabolism. Nitrogen balance is improved only when there is sufficient intake of calories and protein.

Androgens are responsible for the growth spurt of adolescence and for the eventual termination of linear growth which is brought about by fusion of the epiphyseal growth centers. In children, exogenous androgens accelerate linear growth rates but may cause a disproportionate advancement in bone maturation. Use over long periods may result in fusion of the epiphyseal growth centers and termination of the growth process. Androgens have been reported to stimulate the production of red blood cells by enhancing the production of erythropoietic stimulating factor.

During exogenous administration of androgens, endogenous testosterone release is inhibited through feedback inhibition of pituitary luteinizing hormone (LH). At large doses of exogenous androgens, spermatogenesis may also be suppressed through feedback inhibition of pituitary follicle stimulating hormone (FSH).

There is a lack of substantial evidence that androgens are effective in fractures, surgery, convalescence, and functional uterine bleeding.

Indications and Usage for Testosterone Enanthate

Males

Testosterone Enanthate Injection, USP is indicated for replacement therapy in conditions associated with a deficiency or absence of endogenous testosterone.

Primary hypogonadism (congenital or acquired) – Testicular failure due to cryptorchidism, bilateral torsion, orchitis, vanishing testis syndrome, or orchidectomy.

Hypogonadotropic hypogonadism (congenital or acquired) –  Gonadotropin or luteinizing hormone‑releasing hormone (LHRH) deficiency, or pituitary-hypothalamic injury from tumors, trauma, or radiation. (Appropriate adrenal cortical and thyroid hormone replacement therapy are still necessary, however, and are actually of primary importance.)

If the above conditions occur prior to puberty, androgen replacement therapy will be needed during the adolescent years for development of secondary sexual characteristics. Prolonged androgen treatment will be required to maintain sexual characteristics in these and other males who develop testosterone deficiency after puberty.

Safety and efficacy of Testosterone Enanthate Injection, USP in men with age-related hypogonadism have not been established.

Delayed puberty – Testosterone Enanthate Injection, USP may be used to stimulate puberty in carefully selected males with clearly delayed puberty. These patients usually have a familial pattern of delayed puberty that is not secondary to a pathological disorder; puberty is expected to occur spontaneously at a relatively late date. Brief treatment with conservative doses may occasionally be justified in these patients if they do not respond to psychological support. The potential adverse effect on bone maturation should be discussed with the patient and parents prior to androgen administration. An X-ray of the hand and wrist to determine bone age should be obtained every six months to assess the effect of treatment on the epiphyseal centers (see WARNINGS).

Females

Metastatic mammary cancer – Testosterone Enanthate Injection, USP may be used secondarily in women with advancing inoperable metastatic (skeletal) mammary cancer who are one to five years postmenopausal. Primary goals of therapy in these women include ablation of the ovaries. Other methods of counteracting estrogen activity are adrenalectomy, hypophysectomy, and/or antiestrogen therapy. This treatment has also been used in premenopausal women with breast cancer who have benefited from oophorectomy and are considered to have a hormone-responsive tumor. Judgment concerning androgen therapy should be made by an oncologist with expertise in this field.

Overdosage

There have been no reports of acute overdosage with androgens.

How is Testosterone Enanthate Supplied

Testosterone Enanthate Injection, USP 200 mg/mL is available as:

5 mL Multiple Dose vial, Cartons of 1 vial      NDC 0143-9750-01

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