Effects of high-dose ketoconazole and dexamethasone
`on ACTH-stimulated adrenal steroidogenesis
`in orchiectomized prostatic cancer patients
`
`R. De Coster, C. Mahler, L. Denis,
`I. Caers, W. Amery, C. Haelterman,
`M. C. Coene,
`and D. Beerens
`
`Janssen Pharmaceutica Research Laboratories1, Middelheim Hospital2, Antwerp, Belgium
`
`Abstract. The effects of high-dose ketoconazole (i.e.
`400 mg every 8 h) therapy on adrenal steroidogenesis
`were investigated in 7 patients with advanced prostatic
`cancer who no longer responded to orchiectomy. An
`ACTH challenge was performed before and on days 14
`and 28 of high-dose ketoconazole treatment. During
`the last 14 days, dexamethasone (0.5 mg twice daily) was
`administered together with ketoconazole. High-dose
`levels of the
`ketoconazole alone lowered the basal
`androgens by 49\p=n-\66%.It almost completely inhibited
`their stimulation by ACTH, whereas plasma progeste-
`rone was doubled. Basal cortisol was only slightly low-
`ered, but the response to ACTH stimulation was mark-
`edly blunted. Basal and stimulated plasma aldosterone
`remained unaffected. Both basal and stimulated 11\x=req-\
`deoxycortisol, 11-deoxycorticosterone, and, to a lesser
`extent, corticosterone rose more markedly after keto-
`conazole than after placebo. The basal and stimulated
`plasma adrenal androgen levels were further reduced
`after combined ketoconazole-dexamethasone treat-
`ment, whereas plasma corticosterone, 11-deoxycortisol,
`and 11-deoxycorticosterone were lowered in the same
`way as cortisol. Aldosterone and progesterone profiles
`were similar to those observed under high-dose keto-
`conazole, but plasma 17\g=a\-hydroxyprogesteronein-
`creased more markedly than after high-dose ketocona-
`zole alone. These results demonstrate that high-dose
`ketoconazole lowers plasma androgen levels in orchi\x=req-\
`ectomized patients and partly inhibits the gluco- and
`mineralocorticoid syntheses, especially after ACTH\x=req-\
`stimulation. The addition of dexamethasone does not
`only correct the possible consequence of the impair-
`ment of the cortisol production by high-dose ketocona-
`it further reduces the androgen levels and
`zole, but
`
`lowers the plasma concentrations of most precursors,
`for instance 11-deoxycorticosterone, which has some
`physiological mineralocorticoid activity. Therefore, a
`systematic combined therapy may be recommended,
`is given to
`when high-dose ketoconazole treatment
`patients with metastatic prostate cancer.
`
`Ketoconazole is an oral active broad-spectrum
`antimycotic agent (Levine 1982).
`Its antifungal
`properties are due to the blockade of the cyto¬
`chrome P-450 dependent 14-demethylase, cata¬
`lyzing the synthesis of ergosterol
`in yeast and
`fungi (Vanden Bossche 1985). At higher doses,
`ketoconazole also inhibits the 17,20-lyase, a key
`enzyme of the androgen biosynthesis in the testes
`and adrenals and, to a lesser extent, the 11-hy-
`droxylase and cholesterol side-chain cleavage en¬
`zymes of the adrenal gluco- and mineralocorticoid
`biosynthesis (Loose et al. 1983; Santen et al. 1983;
`Pont et al. 1984; Vanden Bossche et al. 1985,
`1987; De Coster et al. 1986). When given to
`prostatic cancer patients at a high dose (i.e. 400
`mg every 8 h), the plasma levels of ketoconazole
`are maintained above 4 mg/1 and a sustained
`inhibition of both testicular and adrenal androgen
`production is achieved (Trachtenberg 1984;
`Heyns et al. 1985).
`The interference of ketoconazole with the
`gluco- and mineralocorticoid pathways has been
`related to some impairment of the adrenal func¬
`tion in a few patients (Trachtenberg & Pont 1984;
`
`

`

`White & Kendall-Taylor 1985; Denis et al. 1985;
`Tapazoglou et al. 1986).
`Therefore it may appear advisable systematical¬
`ly to combine high-dose ketoconazole with a
`glucocorticoid substitution therapy. The present
`study was undertaken to investigate the effects of
`ACTH-challenges on the plasma levels of the
`main adrenal androgens, gluco- and mineralocor-
`ticoids, during high-dose ketoconazole or com¬
`bined ketoconazole-dexamethasone treatment in
`patients with metastatic prostate cancer no longer
`responsive to orchiectomy. This unique patient
`group allowed us to study the effect of the drug
`on the adrenal steroids in a pure state unconta-
`minated by testicular steroids.
`
`Patients and Methods
`
`Patients and study design
`Seven patients (mean age 68 years, range 54—80, mean
`weight 69 kg, 63—80) with histologically confirmed
`metastatic prostate carcinoma were included in this
`study. They had all undergone bilateral orchiectomy 16
`to 81 months (mean 22 months) before, but had recent¬
`ly relapsed. Informed consent was obtained in writing
`and the investigation had been approved by the re¬
`sponsible Ethical Committee. During at least 28 days,
`they were treated with high-dose ketoconazole (400 mg
`every 8 h). The last 14 days, dexamethasone (0.5 mg
`twice daily) was added. Before the onset of treatment
`(day 0) and on days 14 and 28, a 60-min infusion of 0.25
`mg of ACTHi-24 (Synacthen, Ciba, Basel) was admini¬
`stered iv between 08.00 and 10.00 h. Plasma samples
`were taken 20 min before and 30, 60, 90, 120, 180 and
`240 min after onset of the infusion.
`Blood was collected in heparinized tubes, centrifuged
`immediately, and the plasma stored at —20°C.
`The drug was well tolerated. Gastrointestinal upsets
`were observed in 3 patients and caused one of them to
`drop out after 16 days. The clinical characteristics of
`the patients included in this study have been published
`separately in abstract from (Denis et al. 1986) and will
`be described in detail in another study (Denis et al., in
`press).
`
`Hormone assays
`Plasma testosterone, androstenedione, dehydroepi-
`androsterone (DHEA), 17ct-hydroxyprogesterone, and
`progesterone were assayed by
`radioimmunological
`methods as described in detail elsewhere (De Coster et
`al. 1984, 1986). Plasma aldosterone, cortisol, and de-
`hydroepiandrosterone sulphate (DHEAS) were deter¬
`mined by direct assays using iodinated tracer and solid-
`phase antibodies. These commercial kits were pur-
`
`re¬
`
`chased from Cis-Sorin (Gif-sur-Yvette, France), Becton-
`Dickinson Immunodiagnostics (New York, USA), and
`Cambridge Medical Diagnostics (Billerica, USA),
`spectively. The main cross-reacting steroids were: for
`the aldosterone antibody, corticosterone (0.006%), 18-
`hydroxycorticosterone (0.002%), and 11-deoxycortico¬
`for the cortisol antibody,
`sterone (DOC)
`(0.002%);
`11-deoxycortisol (3.5%), and 17o-hydroxyprogesterone
`the DHEAS antibody, DHEA (41%),
`(0.17%);
`for
`androsterone (7.3%), and androstenedione (2.9%). The
`cross-reaction of ketoconazole and dexamethasone in
`these assays was at least lower than 0.08%.
`Plasma corticosterone, DOC, and 11-deoxycortisol
`were measured after extraction and separation by high-
`pressure liquid chromatography (HPLC) as described
`earlier (De Coster et al. 1986).
`Ketoconazole concentrations were determined by
`HPLC in most of the samples obtained before syn-
`acthen infusion (Woestenborghs et al. 1980).
`
`Statistical analysis
`For the dynamic tests, the area under the curve were
`computed by means of the trapezoidal rule. Wilcoxon's
`matched-paired, signed-ranks tests (two-tailed) were
`used for statistical analysis with statistical significance
`defined as S 0.05.
`
`Results
`
`High-dose ketoconazole monotherapy lowered
`the basal plasma concentration of testosterone
`(T), androstenedione (A4), DHEA and DHEAS
`to, respectively, 47% {P = 0.01), 40% [P < 0.01),
`{P = 0.03) of their
`34% (P = 0.03), and 51%,
`control levels (Fig. 1). The rise of adrenal andro¬
`gens observed in control ACTH-challenges, was
`reduced by ketoconazole for A4 (P = 0.05) and
`DHEA (P = 0.01). The area under the curve was
`also lowered for testosterone, from 256 ± 27 to
`153 ± 34 nmol x L1 x tr1 (mean ± SEM), but the
`level of significance was not reached. DHEAS did
`not change after ACTH stimulation.
`The combined ketoconazole-dexamethasone
`treatment also lowered both basal concentrations
`(T to 44%, A4 to 14%, DHEA to 15%, and
`DHEAS to 10% of their control values, P ë 0.05)
`and ACTH-stimulated plasma androgen concen¬
`trations (P = 0.03, Fig. 1). Most of the values
`observed during combined therapy were lower
`than after ketoconazole alone, but the difference
`between the two therapies was only significant for
`DHEAS (P = 0.03).
`The increment of plasma cortisol after ACTH
`
`

`

`control
`
`testosterone
`
`keto
`
`keto + dex
`
`ifWr-H
`
`1.2-
`
`1.0·
`
`0.8
`
`
`
`0.6
`
`0.4
`
`0.2
`
`00
`
`5
`
`androstenedione
`
`s
`
`oE
`
`D.H.E.A
`
`E-
`1 s-
`
`
`4-
`
`7-|D.H.E.A.S.
`il!
`
`3 2
`
`-
`
`Fig. 1.
`Effects of one hour of infusion of synthetic ACTH on plasma androgen levels before (control) and after high-dose
`ketoconazole (keto) and combined high-dose ketoconazole-dexamethasone (keto + dex) treatments in 7 previously
`orchiectomized patients with metastatic prostate cancer. The first two samples of each challenge were obtained
`before the onset of infusion ff) and represent the basal hormonal levels. The results are expressed as mean ± SEM.
`
`î
`
`200
`time (min.)
`
`challenge was almost completely blunted by the
`high-dose ketoconazole treatment (P = 0.01) and
`further reduced by dexamethasone administra¬
`tion (P = 0.05), whereas plasma aldosterone was
`
`not influenced (Figs. 2 and 3). In contrast, both
`basal and stimulated 11-deoxycortisol (P = 0.01),
`DOC (P = 0.01) and, to a lesser extent, corticoste¬
`rone ( = 0.03, basal) rose more markedly after
`
`

`

`control
`
`keto
`
`keto + dex
`
`progesterone
`
`150
`
`12.5
`
`100
`
`7.5-
`
`5.0
`
`2.5
`
`0.0
`
`17-OH progesterone
`
`11 -deoxycortisol
`
`cortisol
`
`klK
`
`l#-H
`
`100
`
`0*
`
`100
`
`200
`
`300
`
`0*
`
`100
`
`200
`
`300
`
`0*
`
`100
`
`200
`time (min.)
`
`S 30
`
`oE8
`
`254
`
`20
`
`15-
`
`10
`
`5
`
`0
`
`40
`
`800
`
`600-
`
`400-
`
`200
`
`0
`
`-
`
`Fig- 2.
`Effects of one hour of infusion of synthetic ACTH on plasma steroid levels of the glucocorticoid pathway before
`and after high-dose ketoconazole and combined high-dose ketoconazole-dexamethasone treatments in 7 previously
`orchiectomized patients with metastatic prostate cancer. The results are expressed as mean ± SEM.
`
`ketoconazole than after placebo (Figs. 2 and 3).
`After combined therapy,
`these steroids were
`lowered in the same way as cortisol but showed
`a somewhat greater spread, particularly after
`
`adrenal stimulation (Figs. 2 and 3). Plasma 17a-
`hydroxyprogesterone levels were not modified by
`high-dose ketoconazole administration, but pro¬
`gesterone levels increased significantly (P = 0.03)
`
`

`

`control
`
`keto
`
`keto + dex
`
`D.O.C.
`
`12·
`
`
`
`corticosterone
`
`11
`
`
`
`10
`
`9 8 7 6 5 4 3 2 1 0
`
`aldosterone
`
`500-
`
`400
`
`300
`
`200
`
`100
`
`0-1
`
` "
`
`— —
`100
`
`— —
`200
`
`— —
`300
`
`— —
`100
`
`—r—
`200
`
`—r—
`300
`
`time (min.)
`
`Fig. 3.
`Effects of one hour of infusion of synthetic ACTH on plasma steroid levels of the mineralocorticoid pathway before
`and after high-dose ketoconazole and combined high-dose ketoconazole-dexamethasone treatment in 7 previously
`orchiectomized patients with metastatic prostate cancer. The results are expressed as mean ± SEM.
`
`(Fig. 2). The addition of dexamethasone in¬
`creased the 17a-hydroxyprogesterone response
`to ACTH but did not modify its basal plasma
`concentrations (Fig. 2). The profile of the proge-
`
`sterone levels was very similar to that observed
`with high-dose ketoconazole alone, but not sig¬
`from that observed in the
`nificantly different
`control challenge.
`
`14-,
`
`_
`
`¡13.
`
`

`

`Discussion
`
`Long-term suppression of both testicular and
`adrenal androgen biosynthesis has been shown to
`occur with first-line high-dose ketoconazole ther¬
`apy of metastatic prostate cancer in man (Trach¬
`tenberg 1984; Heyns et al. 1985). Our data de¬
`monstrate that this treatment also reduces both
`basal and ACTH-stimulated plasma testosterone,
`androstenedione, DHEA and DHEAS levels in
`patients orchiectomized several months before. A
`rapid improvement in pain and performance has
`been noted in such patients (Williams et al. 1986;
`Denis et al. 1985).
`The rise in progesterone is in good agreement
`with previous in vitro and in vivo studies showing
`that ketoconazole blocks the conversion of pro-
`gestins into androgens by inhibiting the cyto-
`chrome P-450 dependent 17,20-lyase and/or 17-
`hydroxylase both in the testes and in the adrenals
`(Santen et al. 1983; De Coster et al. 1984; Sikka et
`al. 1985; Kan et al. 1985; Bhasin et al. 1986;
`VandenBosscheetal. 1985, 1987).
`In the vast majority of patients treated with
`high-dose ketoconazole, basal serum cortisol
`lev¬
`els hardly change (Trachtenberg 1984; Heyns et
`al. 1985; De Coster et al. 1986). Symptoms or
`signs suggestive of some impairment of
`the
`adrenal
`function have been reported in a few
`cases only (Trachtenberg & Pont 1984; White &
`Kendall-Taylor 1985; Denis et al. 1985; Tapazo-
`glou et al. 1986). As a rule, the partial inhibition
`of the cortisol biosynthesis is compensated for by a
`rise in ACTH, which might be the cause of the
`skin pigmentation observed in some cases (Heyns
`et al. 1985; Trachtenberg & Pont 1984; White &
`Kendall-Taylor 1985).
`Our data confirm the blunting of the plasma
`cortisol response to an ACTH challenge (Pont et
`al. 1984) and show that the plasma aldosterone
`increment is not altered by treatment. The rise in
`11-deoxycortisol and of DOC points to a partial
`block of the 1 lß-hydroxylase, which is in agree¬
`ment with previous in vitro studies (Loose et al.
`1983; Kowal 1983). The rather unexpected incre¬
`ment of corticosterone may be related to a partial
`inhibition of another mitochondrial cytochrome
`P-450 dependent enzyme,
`i.e. 18-hydroxylase,
`which converts corticosterone into 18-hydroxy-
`corticosterone,
`the direct precursor of aldoste¬
`rone (Nagai et al. 1985).
`In patients with con¬
`genital adrenal hyperplasia,
`the block of 11-hy-
`
`droxylase is usually incomplete too and it has been
`suggested that the 11- and 18-hydroxytase activ¬
`ities are related (Levine et al. 1980). From a more
`clinical perspective, our data suggest that com¬
`bined high-dose ketoconazole dexamethasone
`treatment may have some other advantages. First,
`it would compensate for a possible adrenal
`im¬
`pairment. Furthermore, in our patients both basal
`and stimulated plasma androgen levels were
`found to be lower than after high-dose ketocon¬
`azole alone.
`In addition, dexamethasone lowered almost all
`the adrenal steroids, including DOC. This might
`prevent the occurrence of peripheral oedema and
`hypertension as reported in a few patients (Baert
`et al. 1985), since in the presence of normal
`aldosterone concentrations, these conditions may
`be signs of excessive mineralocorticoid activity
`owing to markedly increased DOC levels. Further
`studies on the functioning of the renin-angioten-
`sin system are in progress to investigate this point.
`The only steroids found to increase after
`ACTH-stimulation during the combined therapy
`are aldosterone, progesterone, and, particularly,
`17a-hydroxyprogesterone. The rise in the latter
`progestin is difficult to interpret, but may reflect
`differences in enzymatic activities in the presence
`or absence of chronic ACTH stimulation (high-
`dose ketoconazole or combined therapy). How¬
`ever, a direct effect of dexamethasone on the
`adrenal biosynthesis is an alternative explanation
`(Carsiaetal. 1983).
`In conclusion, clinical and endocrinological
`data suggest that corticosteroid supplementation
`may have several advantages during high-dose
`ketoconazole therapy for prostatic cancer.
`On the other hand, high-dose ketoconazole
`alone has proven to give long-lasting remission,
`and the development of more potent and selective
`derivatives may open new possibilities for mono-
`therapy of prostate cancer.
`
`Acknowledgments
`The authors wish to thank the whole staff of the
`Urologie Department of Middelheim Hospital, L. Wou-
`ters for statistical analyses, and L. Leijssen and K.
`Donne who prepared the manuscript.
`This work was in part supported by a IWONL grant.
`
`

`

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`—
`
`—
`
`Received September 15th, 1986.
`Accepted February 9th, 1987.
`
`Dr R. De Coster,
`Janssen Pharmaceutica Research Laboratories,
`Turnhoutseweg 30,
`B2340 Beerse,
`Belgium.
`
`