Use, misuse and abuse of androgens

• Androgen replacement therapy (ART) is usually life-long, and should only be started after androgen deficiency has been proven by hormone assays. The therapeutic goal is to maintain physiological testosterone levels.

• Testosterone rather than synthetic androgens should be used.

• Oral 17α-alkylated androgens are hepatotoxic and should not be used for ART.

• There is no indication for androgen therapy in male infertility. Although androgen deficiency is an uncommon cause of erectile dysfunction, all men presenting with erectile dysfunction should be evaluated for androgen deficiency. If androgen deficiency is confirmed, investigation for the underlying pathological cause is required.

• Contraindications to androgen therapy are prostate and breast cancer. Precautions include using lower starting doses for older men and induction of puberty. Intramuscular injections should be avoided in men with bleeding disorders. Androgen-sensitive epilepsy, migraine, sleep apnoea, polycythaemia or fluid overload need to be considered. Competitive athletes should be warned about the risks of disqualification.

• ART should be initiated with intramuscular injections of testosterone esters, 250 mg every two weeks. Maintenance requires tailoring treatment modality to the patient's convenience. Modalities currently available include testosterone injections, implants, or capsules. Choice depends on convenience, cost, availability and familiarity.

• There is no convincing evidence that, in the absence of proven androgen deficiency, androgen therapy is effective and safe for older men per se, in men with chronic non-gonadal disease, or for treatment of non-specific symptoms. Until further evidence is available, such treatment cannot be recommended.

Potential extensions of classical indications to partial androgen deficiency remain to be fully evaluated for clinical safety and efficacy. These indications include age, androgen deficiency secondary to a chronic medical condition or its treatment, hormonal male contraception, and postmenopausal symptoms.^4-6 Until more definitive objective evidence is available regarding the safety and efficacy of prescribing androgens for these indications, they remain suitable for carefully monitored, controlled clinical research trials, but not for routine medical treatment.

Pharmacological applications of androgens (Box 1) usually represent second-line therapy where more specific treatments are not yet available or have failed.

Androgen treatment can evoke a strong placebo response. In men without genuine androgen deficiency, this placebo effect invariably wanes with time, leading to confusion and dissatisfaction with treatment. In addition, once androgen therapy has commenced, the biochemical changes can cloud further interpretation of results for months. Therefore, androgen replacement therapy should be commenced only after androgen deficiency is clearly established.^2,3

Serum LH, follicle-stimulating hormone and testosterone levels should be measured, on at least two separate days and preferably in the morning, to minimise the effects of random and laboratory fluctuations and diurnal rhythms. Direct measurements of free testosterone, if available, may help establish the diagnosis of androgen deficiency, but require extensive validation. Indirect measurements of free testosterone, such as the free androgen index (testosterone/sex hormone binding globulin [SHBG] ratio), correspond poorly with direct measurements and lack empirical validation as a diagnostic test.

Additional tests that may be required to identify underlying disorders include karyotyping, pituitary radiology and measurement of prolactin levels, serum ferritin levels, iron saturation and, increasingly, genetic diagnosis.

Androgen deficiency is unlikely in men with mean testis volume > 20 mL without atrophy, with a plasma testosterone level consistently above 20 nmol/L, or presenting with erectile dysfunction and a plasma testosterone level consistently above 8 nmol/L (Box 2). Where the diagnosis is not clear, referral to a clinical endocrinologist with experience in this area is recommended.¹

Dosage: Standard ART is either testosterone enanthate (Primoteston in castor oil; Schering) or mixed testosterone esters (Sustanon in arachis oil; Organon) as 250 mg in 1 mL oil at 14-day intervals. Deep intramuscular injections are usually given into the upper and outer quadrant of the buttock, although some patients prefer the deltoid or lateral thigh muscle sites. Few men can manage self-injection with the viscous oil vehicle.

For all ART, testosterone and its esters should be used in preference to synthetic androgens, because of their established safety and efficacy, as well as ease of dose-titration and assay monitoring.

Lower starting doses may occasionally be needed, especially in previously untreated elderly men and during first induction of puberty. Less frequent dosing intervals (eg, every three weeks) are occasionally necessary for those unable or unwilling to have standard dosage, but are accompanied by more extreme peaks and troughs in blood testosterone levels, which may exaggerate symptom fluctuations.

An inadequate clinical response raises doubt about androgen deficiency as the cause of recalcitrant symptoms. Rarely, an inadequate clinical response may require increased dosage. If suboptimal symptomatic benefit is supported by biochemical evidence of inadequate maintenance of androgen levels (low trough testosterone levels with or without persistently supranormal LH levels in primary hypogonadism), the same dose may be injected at 10-day intervals. Persistently inadequate responses indicate that unresponsive symptoms are not due to androgen deficiency; further escalation in dose or frequency is not warranted. Men with mild or partial androgen resistance due to androgen-receptor mutations may benefit from high-dose androgen therapy.

As the underlying disorders are almost always permanent, life-long ART after the age of puberty is usually necessary. Long term therapeutic compliance depends on an acceptable regimen. Crossover studies indicate that patients strongly prefer the stable testosterone levels and smoother clinical effects provided by implants or transdermal formulations, compared with the wide fluctuations in testosterone levels and symptoms during intramuscular testosterone ester injections. Thus, although ART should commence with injections, alternative modalities (Box 3) may improve compliance. Factors to consider include cost, convenience, availability, familiarity with alternatives, and tolerance for frequent injections.

Monitoring: Monitoring of ART is mainly to ensure effective androgen replacement by a regimen tailored to the patient's needs, aiming to maintain adequate therapeutic compliance by continuation of treatment. Serial clinical observation of clinical well-being and major symptoms of androgen deficiency, together with limited numbers of hormonal assays, is usually adequate. Restoration of sexual function has a low threshold for androgen action, so adequate libido and potency is a necessary, but not sufficient, indication of clinically adequate androgen replacement.

Blood hormone assays have limited utility in optimising an ART regimen at the start of treatment and in evaluating androgen replacement. Trough blood testosterone levels (ie, before the next scheduled dose) within the eugonadal reference range can be a valuable guide to the adequacy of parenteral androgen replacement, but random blood testosterone levels are not useful for monitoring with either oral or injectable testosterone. In men with hypergonadotropic hypogonadism, suppression of blood LH levels into the eugonadal reference range indicates adequate ART, whereas persistent non-suppression of LH after 3-6 months of regular treatment indicates inadequate dosage or compliance. In hypogonadotropic hypogonadism, blood gonadotropin levels are uninterpretable. Serial evaluation of bone density (especially vertebral trabecular bone) by dual-photon absorptiometry at 1-2-year intervals may be useful in evaluating the adequacy of long-term androgen effects on bone. Other biochemical indices of androgen action, such as haemoglobin, SHBG, and high density lipoprotein cholesterol levels, reflect only supraphysiological effects and are too insensitive for routine monitoring of ART.

Androgen deficiency is protective against prostate disease, and ART may restore the risks to those equivalent to, but no more than, eugonadal men of similar age. Screening of men receiving ART for cardiovascular and prostate disease need be no more intensive than for men of similar age not on ART.

Oral synthetic androgens that have a 17α-alkyl substituent (oxandrolone, fluoxymesterone, danazol) are inherently hepatotoxic, causing cholestatic hepatitis, peliosis hepatis and hepatic tumours. Other classes of synthetic androgen, such as 19-nortestosterone derivatives (nandrolone, MENT) and the 1-methyl androgens (mesterolone, methenolone), are not hepatotoxic.

Absolute contraindications to androgen therapy are prostate or breast cancer in men. Androgen therapy should be started in men over the age of 40 only after exclusion of undiagnosed prostate disease. Precautions are required for:

• older men starting androgen treatment, where it may precipitate urinary obstruction or unfamiliar increases in libido;

• pubertal boys, in whom excessive dosage may accelerate epiphyseal closure, leading to shortened final stature;

• parenteral androgen therapy in men with bleeding disorders;

• competitive athletes, who may be disqualified;

• androgen-sensitive epilepsy, migraine, sleep apnoea or polycythaemia; and

• cardiac or renal failure or severe hypertension susceptible to fluid overload from sodium and fluid retention.

Male infertility: There is no indication for androgen therapy in male infertility. The only likely consequence is an adverse effect of suppressing spermatogenesis.

Male sexual dysfunction or impotence: Androgen deficiency (with or without hyperprolactinaemia) is an uncommon (< 5%) cause of men presenting with erectile dysfunction. In such men, excluding androgen deficiency as a readily treatable underlying cause is essential. In the unusual event of severe androgen deficiency presenting with erectile dysfunction, the underlying cause needs to be identified, and plans for life-long ART need to be established.

"Male menopause" or "andropause": There is still no evidence that the modest decreases in circulating blood testosterone levels which commence during mid-life have any clinical importance. The risks and benefits of androgen supplementation for partially androgen-deficient older men require further evaluation by placebo-controlled studies. Androgen treatment may be inappropriate, wasteful, and involve placebo effects. Terms such as "male menopause" and "andropause" are misleading; they have little place in meaningful medical or scientific discourse.

Elderly men (> 65 years):¹⁸ There is no basis for androgen therapy based on age per se. Further controlled clinical trials are needed to evaluate the potential role of androgen supplementation in ageing. While some preliminary placebo-controlled studies suggest short-term benefits for muscle, bone and quality of life, findings are not yet consistent and the identification of appropriate treatment objectives and target subgroups, as well as overall analyses of risks, benefits and costs, are lacking. Specifically, it remains to be determined whether androgen supplementation has significant and sustained clinical benefits in older men with low-normal plasma total testosterone and normal LH levels. At present, there is no basis for androgen treatment outside properly designed clinical trials.

Treatment of non-specific symptoms: There is no basis for androgen therapy based on symptoms in the absence of established androgen deficiency. In addition to the unproven safety and efficacy, the placebo effect of androgen injections may be confusing to both doctor and patient. When placebo effects wane, further confusion and dissatisfaction with treatment may be expected.

Medical prescription appears to support only a small proportion of illicit androgen use, but such activity has been formally ruled as a breach of professional standards by medical boards in most States and by the Royal Australasian College of Physicians. Highly motivated young men can be very sophisticated in manipulating and pressuring general practitioners while attempting to obtain prescriptions for androgens. The doctor is often led to believe that other practitioners are prescribing androgens for young men, and that he or she is being uncaring or negligent by not acceding to the patient's wishes. We recommend that general practitioners resist these pressures.

Fortunately, most people appear ultimately to lose interest in this form of drug abuse.

Diagnosis and management of androgen deficiency

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2. Plymate SR. Male Hypogonadism. In: Becker KL (ed): Principles and Practice of Endocrinology and Metabolism. 2nd ed. Philadelphia: J B Lippincott Company, 1995: 1056-1082.
3. Nieschlag E, Wang C, Handelsman DJ, et al (eds) (1992). Guidelines for the use of androgens in men. Geneva, Special Programme of Research, Development and Research Training in Human Reproduction of the World Health Organisation.

   Male contraception
   

4. Cummings DE, Bremner WJ. Prospects for new hormonal male contraceptives. In: Bremner WJ (ed): Clinical Andrology. Philadelphia: W B Saunders Company, 1994: 893-922.
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   Androgen therapy in systemic disease

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   Comparative pharmacology of androgen formulations

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    Safety of androgens

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16. Behre HM, Bohmeyer J, Nieschlag E. Prostate volume in testosterone-treated and untreated hypogonadal men in comparison to age-matched normal controls. Clin Endocrinol (Oxf) 1994; 40: 341-349.
17. Gooren LJ, Polderman KH. Safety aspects of androgen therapy. In: Nieschlag E, Behre HM (eds): Testosterone: Action, Deficiency and Substitution. Berlin: Springer-Verlag, 1990: 182-203.

    Androgen and the ageing male

18. Tenover JL. Androgen therapy in aging men. In: Bhasin S, Gabelnick HL, Spieler JM, et al (eds): Pharmacology, Biology, and Clinical Applications of Androgens: Current Status and Future Prospects. New York: Wiley-Liss, 1996: 309-318.

    Androgen abuse

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22. Wilson JD. Androgen abuse by athletes. Endocr Rev 1988; 9: 181-199.
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24. Young NR, Baker HWG, Liu G, Seeman E. Body composition and muscle strength in healthy men receiving testosterone enanthate for contraception. J Clin Endocrinol Metab 1993; 77: 1028-1032.

Reprints will not be available from the authors.
Correspondence: Associate Professor J D Zajac, Department of Medicine, University of Melbourne, Royal Melbourne Hospital, Parkville, VIC 3050.
j.zajacATmedicine.unimelb.edu.au

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