Different Therapeutic Efficacy of Ketoconazole in Patients with Cushing’s Syndrome
D. Engelhardt1, K. Jacob2, and H.G. Doerr3
1 Medizinische Klinik II,
2 Institut für Klinische Chemie, Klinikum Grosshadern, und
3 Kinderklinik im von Haunerschen Kinderspital, Universität München
Summary. The property of ketoconazole to inhibit adrenal biosynthesis of cortisol was used in a clini- cal study of 14 patients with Cushing’s syndrome (pituitary-dependent Cushing’s disease, n=10; ad- renocortical adenoma, n=2; adrenocortical carci- noma, n=1; ectopic ACTH syndrome, n=1). Five patients were treated in a short-term manner (1000 mg over 24 h) and nine patients for a longer period (600 mg/die from 1 week up to 12 months). After short-term administration of ketoconazole, serum cortisol levels fell distinctly only in the pa- tient with adrenocortical adenoma, but not at all or only slightly in the other patients, whereas se- rum levels of progesterone and 11-deoxy-com- pounds increased markedly in all patients, with the exception of the patient with adrenocortical carci- noma. Plasma ACTH levels increased in the pa- tients with Cushing’s disease but not in the patients with tumor. After long-term treatment of three pa- tients with Cushing’s disease over 3, 10, and 12 months, the clinical signs of hypercortisolism persisted or were only slightly ameliorated. In these three patients as well as in three other patients with Cushing’s disease treated for a shorter period of 1 to 4 weeks, serum and urinary cortisol levels decreased, but were not normalized, whereas plas- ma ACTH levels increased variably. Only in one patient with Cushing’s disease, in the second pa- tient with adrenocortical adenoma, and in the pa- tient with ectopic ACTH syndrome, serum and uri- nary cortisol levels returned to normal. We con- cluded from our data, that the antimycotic drug
inhibits biosynthesis of cortisol by blocking adre- nal 11B- and 17x-hydroxylase activity. This effect was compensated in part by a rebound increase of pituitary ACTH secretion in most patients with Cushing’s disease. Therefore, ketoconazole treat- ment is above all effective in patients with Cush- ing’s syndrome due to an adrenal tumor or in pa- tients with ectopic ACTH syndrome, who cannot respond with an increased pituitary ACTH secre- tion.
Key words: Ketoconazole - Cushing’s syndrome - Short-term administration - Long-term treat- ment - 118-hydroxylase - Inhibition of steroid bio- synthesis
The antifungal drug ketoconazole is a potent in- hibitor of steroid biosynthesis in man. In vivo stud- ies and in vitro incubation experiments with adre- nal tissue slices demonstrated that the agent blocks adrenal cortisol and aldosterone biosynthesis in normal persons and in patients with Cushing’s syn- drome by inhibiting adrenal 17x, 11ß-, and 18-hy- droxylase activity [3, 4, 5, 8]. In addition, ketocon- azole has an effect on androgen biosynthesis by inhibiting 17x- and C17-20-desmolase activity in human adrenal and testicular tissue [2, 17]. Re- cently, varying data about the efficacy of ketocon- azole in the treatment of patients with Cushing’s disease have been reported [6, 9, 14]. Therefore, we studied the effect of ketoconazole in 14 patients with different forms of Cushing’s syndrome (five patients with a short-term administration and nine patients with therapy over a longer period) to ob- tain more clinical experience with this therapy and to investigate in detail the effects of ketoconazole
Abbreviations: ACTH = Adrenocorticotropic hormone; AA = Adrenocortical adenoma; AC=Adrenocortical carcinoma; B=Corticosterone; CRH = Corticotropin-releasing hormone; EAS = Ectopic ACTH syndrome; PDCD =Pituitary-dependent Cushing’s disease; P = Progesterone; 17OH-P = 17-hydroxypro- gesterone; RIA= Radioimmunoassay; S=11-deoxycortisol; DOC=11-deoxycorticosterone
on the pituitary and the adrenals by measurement of plasma ACTH levels, serum levels of cortisol, precursor steroids of cortisol biosynthesis, and uri- nary excretion of free cortisol.
Patients and Methods
We studied the short-term and long-term effects of ketoconazole administration on the pituitary and the adrenals in 14 patients with Cushing’s syn- drome (pituitary-dependent Cushing’s disease (PDCD), n=10; adrenocortical adenoma (AA), n=2; adrenocortical carcinoma (AC), n=1; and ectopic ACTH syndrome (EAS), n=1). All pa- tients (3 men, 11 women) had marked clinical signs of cortisol excess. The diagnosis of Cushing’s syn- drome was made after demonstrating increased se- rum cortisol levels, absence of diurnal variation of serum cortisol (determined at 08:00 a.m., 02:00 p.m., 07:00 p.m., and 11:00 p.m.), increased excretion of urinary free cortisol, and reduced sup- pression of serum and urinary cortisol by low dose dexamethasone (3 mg/die for 3 days). The diagno- sis of PDCD was established after demonstrating elevated plasma ACTH levels, a suppression of plasma ACTH, serum and urinary cortisol by high- dose dexamethasone (9 mg/die for 3 days) and responsiveness of plasma ACTH and serum cor- tisol to 100 µg CRH i.v. The diagnosis of AA and AC was made after demonstrating decreased plas- ma ACTH levels without stimulation after admin- istering CRH, high serum and urinary cortisol lev- els not suppressed by high dose dexamethasone, and after detection of an adrenal tumor by CT (NMR) scanning. The diagnosis of EAS was made by high plasma ACTH and high serum and urinary cortisol levels without suppression by high-dose dexamethasone or stimulation with CRH and proof of a pancreatic tumor by CT scanning. Five patients (PDCD, no. 1-3; AA, no. 4; and AC, no. 5) were treated with ketoconazole in a short- term study (200 mg orally every 5 h for 25 h), and nine patients (PDCD, no. 6-12; EAS, no. 13; AA, no. 14) were treated with ketoconazole (200 mg or- ally every 8 h =600 mg/24 h) over a longer period from 7 days to 12 months. Serum levels of proges- terone (P), 17a-hydroxyprogesterone (17OH-P), 11-deoxycortisol (S), 11-deoxycorticosterone (DOC), corticosterone (B), and cortisol were si- multaneously measured from the same serum sam- ples in patients no. 1-5, 6, 9, and 13. This micro- method of multisteroid analysis has been pre- viously described and evaluated [13].
Serum cortisol levels (normal range, 90-190 ng/ ml) and 24-h urinary free cortisol excretion (nor-
mal range, 40-150 µg/24 h) were measured in pa- tients no. 6-14 (long-term study group) using a di- rect homologous radioimmunoassay (RIA) [15]. Plasma ACTH levels in the short-term study group were measured by a specific RIA after extraction [10], whereas ACTH levels in the long-term study group were measured by a specific RIA without extraction [11], using an IgG-ACTH-1 antibody (IgG, Nashville, TN) with modifications (1 µg ACTH in 10 ul 0.01 N HCI) labelled with 30 ul 125J (0.4 mCi)). The lowest sensitivity of the stan- dard curve was 5-10 pg ACTH/ml plasma. The intra-assay coefficient was 4.4% (MV, 16.0 pg/ml; n=8) and 6.1% (MV, 45.1 pg/ml; n=8), the inter- assay coefficient of variation was 15.6% (MV, 15.7 pg/ml; n=11) and 19.9% (MV, 40.8 pg/ml; n=11). The normal range of plasma ACTH was 10-30 pg/ml. Blood samples were always drawn between 08:00 a.m. and 09:00 a.m. (for steroids in polystyrene tubes, for ACTH in EDTA-coated polystyrene tubes with 400 KIE Aprotinine at 0°C, immediately centrifuged and stored at -40° C until assayed). The 24-h urinary specimens were collected from 07:00 a.m. until 07:00 a.m. on the next day.
Results
The short-term administration of 1000 mg keto- conazole over 24 h induced only a slight decrease of serum cortisol levels in the three patients with PDCD (no. 1-3) and in patient no. 5 with AC, whereas in patient no. 4 with Cushing’s syndrome due to AA a clear fall of serum cortisol levels to half the baseline levels was seen (Table 1). Because serum S levels increased in all patients except the patient with AC (no. 5), the relative ratios of S/F also showed an increase in patients no. 1-4. Serum levels of B, DOC, P, and 17OH-P also increased after ketoconazole. The increase of DOC was somewhat more pronounced than the increase of B (except in the patient with AA (no. 4)) and the increase of P more than of 17OH-P, thus the rela- tive ratios of DOC/B (except in patient no. 4) and P/17OH-P (all patients) rose distinctly. Plasma ACTH levels rose in patient no. 1 and 3 with PDCD but not in patient no. 5 with AC.
In seven patients (no. 6-12) with PDCD, one patient with AA (no. 14), and one patient with EAS (no. 13) ketoconazole (600 mg/die) was ad- ministered for a period of 1 week for up to 12 months. Serum cortisol, urinary free cortisol, and plasma ACTH levels are listed in Table 2, whereas the values in the course over 10 months from patient no. 6 with PDCD are depicted in
| Patient no. | P | 17OH-P | S | DOC | B | F | S/F | DOC/B | P/17OH-P | ACTH | |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Short-term study | |||||||||||
| 1 | Basal | 0.10 | 0.28 | 0.84 | 0.03 | 4.09 | 344 | 1.00 | 1.00 | 1.00 | 23 |
| 24 h | 0.43 | 0.44 | 1.79 | 0.48 | 3.47 | 206 | 3.62 | 19.40 | 2.79 | 200 | |
| 2 | Basal | - | - | 2.44 | - | - | 213 | 1.00 | - | - | - |
| 24 h | - | - | 12.60 | - | - | 214 | 5.46 | - | - | - | |
| 3 | Basal | 0.22 | 1.75 | 2.33 | 0.08 | 4.44 | 288 | 1.00 | 1.00 | 1.00 | 44 |
| 24 h | 3.27 | 2.96 | 17.50 | 4.72 | 17.80 | 191 | 11.80 | 15.00 | 8.49 | 83 | |
| 4 | Basal | 0.23 | 0.33 | 0.78 | 0.08 | 1.41 | 504 | 1.00 | 1.00 | 1.00 | 5 |
| 24 h | 0.83 | 0.41 | 2.96 | 0.19 | 8.09 | 254 | 7.80 | 0.40 | 2.89 | - | |
| 5 | Basal | 0.17 | 1.02 | 16.40 | 0.32 | 0.80 | 330 | 1.00 | 1.00 | 1.00 | 10 |
| 24 h | 0.25 | 0.67 | 14.30 | 0.37 | 0.65 | 287 | 1.00 | 1.43 | 2.19 | 10 | |
| Long-term study | |||||||||||
| 6 | Basal | 0.06 | 0.63 | 0.35 | 0.01 | 2.47 | 265 | 1.00 | 1.00 | 1.00 | 50 |
| 1 Month | 1.62 | 1.23 | 10.40 | 6.67 | 11.50 | 118 | 40.40 | 145.00 | 13.20 | 120 | |
| 5 Months | 0.83 | 2.27 | 4.77 | 2.20 | 17.10 | 216 | 17.00 | 32.20 | 3.66 | 130 | |
| 10 Months | 1.02 | 2.38 | 3.18 | 3.07 | 7.73 | 209 | 11.70 | 91.20 | 4.29 | 110 | |
| 9 | Basal | 0.16 | 0.29 | 2.70 | 0.27 | 3.20 | 186 | 1.00 | 1.00 | 1.00 | 64 |
| 1 Week | 1.49 | 0.68 | 17.60 | 5.48 | 24.50 | 131 | 9.27 | 2.66 | 3.98 | - | |
| 2 Weeks | 0.57 | 1.46 | 18.60 | 7.85 | 14.50 | 114 | 11.30 | 6.44 | 0.55 | 72 | |
| 13 | Basal | 0.20 | 0.99 | 3.76 | 0.40 | 10.90 | 410 | 1.00 | 1.00 | 1.00 | 180 |
| 1 Week | 0.16 | - | 2.03 | 0.17 | 10.50 | 134 | 1.68 | 0.44 | - | 128 | |
| 3 Weeks | 0.01 | 0.23 | 2.75 | 0.20 | 5.38 | 197 | 1.55 | 1.00 | 0.22 | 94 | |
| 3 Months | 0.09 | 0.57 | 1.97 | 0.53 | 5.31 | 104 | 2.10 | 2.70 | 0.79 | 40 | |
Fig. 1. In addition, results of the multisteroid anal- ysis in patients no. 6 and 9 with PDCD and no. 13 with EAS are shown in Table 1.
Three of seven patients (no. 6, 7, 8) with PDCD (one before and two after unsuccessful transsphen- oidal surgery) were treated for 10, 12, and 3 months, respectively. Thereafter, bilateral adre- nalectomy was necessary because of persistent signs of hypercortisolism. Two of these three pa- tients (no. 6 an 8) showed no definitive improve- ment of clinical signs of Cushing’s disease, one of them (no. 6) developed labile hypertension and low serum potassium levels and the other one signs of liver toxicity (gamma-GT 580 U/1, GPT 254 U/1, GOT 129 U/1). In the third patient (no. 7) a dia- betes mellitus and severe muscle weakness im- proved slightly. In all three patients, serum cortisol levels as well as urinary excretion of free cortisol decreased but could not be normalized. Plasma ACTH levels doubled in patient no. 6, whereas in the other two patients they fluctuated and were not different from the initial values before treat-
ment. In four of seven patients with PDCD (no. 9- 12), ketoconazole was given over a shorter time of 1 to 4 weeks before transsphenoidal surgery was performed and no clinical benefit could be seen during this short period. Serum cortisol and uri- nary cortisol levels decreased but did not return to normal, and plasma ACTH levels showed a ten- dency to increase (no. 10 and 12). However, in pa- tient no. 9 with PDCD, serum levels as well as urinary cortisol levels were normalized after 2 weeks of therapy, whereas the plasma ACTH lev- el was not different from the initial value. In pa- tient no. 11 serum levels of cortisol fell distinctly, but did not reach the normal range within 1 week. In this case an increase of plasma ACTH levels could also not be detected. In the second patient with AA (no. 14) serum and urinary values of cor- tisol fell to very low levels within 1 week and plas- ma ACTH levels remained undetectable for 2 weeks. In patient no. 13 with EAS, a normaliza- tion of serum and urinary cortisol levels as well as a slight decrease of plasma ACTH levels could
| Patient | Basal | 1 Week | 2 Weeks | 4 Weeks | 2 Months | 3 Months | 5 Months | 10 Months | 12 Months | ||
|---|---|---|---|---|---|---|---|---|---|---|---|
| no. | |||||||||||
| Serum cortisol (ng/ml) | |||||||||||
| 6 | PDCD | 265 | 171 | 228 | 118 | 154 | 198 | 216 | 209 | ||
| 7 | PDCD | 375 | 188 | 137 | 198 | 186 | 245 | 209 | 237 | ||
| 8 | PDCD | 254 | 217 | 252 | 196 | 256 | |||||
| 9 | PDCD | 186 | 131 | 114 | |||||||
| 10 | PDCD | 234 | 214 | 235 | |||||||
| 11 | PDCD | 220 | 179 | ||||||||
| 12 | PDCD | 390 | 372 | 312 | |||||||
| 13 | EAS | 410 | 134 | 160 | 109 | 123 | 104 | ||||
| 14 | AA | 397 | 2 | ||||||||
| Urinary cortisol (ug/24 h) | |||||||||||
| 6 | PDCD | 1257 | 284 | 285 | 784 | 308 | 296 | 540 | 372 | ||
| 7 | PDCD | 367 | 211 | 268 | 249 | 183 | 256 | 266 | 301 | 294 | |
| 8 | PDCD | 1245 | 1000 | 480 | 702 | ||||||
| 9 | PDCD | 345 | 95 | ||||||||
| 10 | PDCD | 519 | 350 | 622 | |||||||
| 11 | PDCD | 667 | 189 | ||||||||
| 12 | PDCD | 488 | 638 | 344 | |||||||
| 13 | EAS | 799 | 77 | 84 | 97 | 129 | 63 | ||||
| 14 | AA | 967 | 52 | ||||||||
| ACTH (pg/ml) | |||||||||||
| 6 | PDCD | 50 | 60 | 110 | 120 | 68 | 120 | 130 | 110 | ||
| 7 | PDCD | 62 | 58 | 74 | 80 | 58 | 100 | 64 | 73 | ||
| 8 | PDCD | 46 | 80 | 22 | 29 | ||||||
| 9 | PDCD | 64 | 72 | ||||||||
| 10 | PDCD | 64 | 128 | 400 | |||||||
| 11 | PDCD | 44 | 37 | ||||||||
| 12 | PDCD | 42 | 61 | 60 | |||||||
| 13 | EAS | 180 | 128 | 94ª | 42 | 82 | 40 | ||||
| 14 | AA | <5 | <5 | <5 | |||||||
a
Three weeks
PAT.T.H.Ở
Ketoconazole (600mg/24h)
Cyproh.
ACTH (plasma) pg/ml
120
80
40
20
F
30
(serum)
ug/dl
20
10
F
1200
(urine)
ug/24h
800
400
150
12/85
2/86
4/86
6/86
8/86
10/86
12/86
Pat.T.H.
Ketoconazole (600mg/24h)
P
(ng/ml)
2
1
17«-P
2
(ng/ml)
1
DOC (ng/ml)
6
3
B
(ng/ml)
20
10
S
10
(ng/ml)
F
(ug/dl)
20
10
11/85
5/86
7/86
9/86
be observed during the treatment period. The re- sults of the multisteroid analysis performed in pa- tients no. 6, 9, and 13 are shown in Table 1 and Fig. 2. During a study period of 4 months and 2 weeks, respectively, levels of P, 17OH-P, S, DOC, and B were clearly elevated and above the basal levels before treatment in patients no. 6 and 9 with PDCD, whereas in patient no. 13 with EAS all steroid levels decreased in the course of 3 months’ treatment with ketoconazole.
Discussion
The short-term administration of ketoconazole (1000 mg/24 h) in five patients with Cushing’s syn- drome induced only in the patient with an AA a clear fall of serum cortisol, whereas in the other patients with PDCD and AC cortisol levels did not decrease or fell slightly. The serum levels of S and DOC, however, increased sharply up to ten-
fold the basal values in all patients, with the excep- tion of the AC case. Thus, it was shown that keto- conazole inhibits the 11ß-hydroxylase enzyme sys- tem of the adrenals, a fact which has already been demonstrated by in vitro incubation studies [4]. In addition, the more pronounced increase of P than of 17OH-P as well as the slight increase of B after ketoconazole indicated an inhibition of the 17a-hydroxylase enzyme system, which has also been demonstrated in incubation studies with ad- renocortical tissue [8]. In summary, these data to- gether with the finding of elevated plasma ACTH levels after short-term ketoconazole administration in patients with PDCD point to a predominant effect of ketoconazole on the adrenal cortex. Con- sequently, the in vitro inhibiting effect of ketocona- zole on ACTH secretion of rat corticotrops ap- pears to have no clinical significance [16].
After long-term treatment of three patients with PDCD with ketoconazole (600 mg/die) over 3 to 12 months, serum cortisol as well as urinary cortisol levels decreased only slightly but were never normalized and plasma ACTH levels in- creased variably. In all three patients the clinical signs of hypercortisolism persisted (with the excep- tion of improved diabetes mellitus and muscle weakness in one patient (no. 7)), and finally, bilat- eral adrenalectomy was performed in all three cases. One of these patients developed hyperten- sion and low serum potassium levels. Serum levels of 11-deoxysteroids, S and DOC, were elevated in this patient over an observation period of 4 months (Fig. 2), suggesting constant mineralo- corticoid excess. In addition, after ketoconazole therapy of four other patients with PDCD over a shorter period of 1 to 4 weeks, again, serum and urinary cortisol levels only slightly decreased in two patients (no. 10, 12). But in one female patient with PDCD and predominant androgen excess (no. 9), serum cortisol levels decreased and urinary cortisol levels were normalized within 2 weeks of therapy and plasma levels of ACTH did not defini- tively increase. In another patient (no. 11) urinary cortisol levels decreased, but were not normalized within 1 week and plasma ACTH levels did not increase again. A distinct decrease of serum and urinary cortisol levels within 1 week with persistent undetectable plasma ACTH values could be ob- tained by ketoconazole in the second patient with AA (no. 14). A similar response of serum cortisol levels after oral ketoconazole was seen in two other patients with AA and an adrenal rest tumor of the liver, respectively [1, 3]. Normalization of se- rum cortisol levels and urinary cortisol excretion without increase of DOC and S levels could be also observed in the patient with EAS, which is
similar to another case with EAS and normaliza- tion of serum cortisol levels after ketoconazole therapy [12]. We suggest, therefore, that the thera- peutic effect of ketoconazole can be expected in patients with pituitary-independent hypercortisol- ism, whereas in patients with PDCD, the compen- satory increase of ACTH secretion abolishes a rele- vant suppression of cortisol secretion by ketocona- zole in most cases.
Three other clinical studies on ketoconazole treatment of patients with PDCD have been pub- lished recently [6, 9, 14]. In the first trial, it could be shown in five patients that ketoconazole (begin- ning with 800 mg/die, then 600 mg/die) was effec- tive in normalizing urinary cortisol excretion with- in 1 day up to 1 week and the clinical signs of hy- percortisolism disappeared [14]. Additionally, the authors suggested that during ketoconazole thera- py no mineralocorticoid excess would occur. How- ever, they did not measure the levels of 11-deoxy- steroids. A compensatory increase of ACTH levels was not found. In the second study ketoconazole (600-800 mg/die) was given over months in seven patients with PDCD. After 1 and 3 months three of seven patients had normalized levels of urinary cortisol excretion [6]. Plasma ACTH did not change in these patients. In the last report six patients with PDCD were treated with ketoconazole 800 mg daily, three of four patients had normal urinary cortisol levels after 7 days, however, three of six patients had signs of hepatotoxicity. Plasma ACTH levels were measured but not listed [9]. The finding in these three studies, that the ACTH levels were not changed, could be related to methodolog- ical problems with the ACTH determination. The contradicting results may either represent a differ- ence in the selection of the patients or could be due to the heterogeneous group of patients itself. Our results of decreasing urinary cortisol levels after ketoconazole in two patients (no. 7, 11) with PDCD, show that at least some patients respond to ketoconazole treatment. However, the other pa- tients with PDCD in our study did not respond to the therapy.
Recently, in a short report [7] a therapeutic ef- fect of ketokonazole was also reported in patients with hyperaldosteronism. In our patients with Cushing’s syndrome the aldosterone levels were in the normal range (data not reported) and we were not able to find a decrease of serum levels of aldos- terone after ketoconazole therapy.
Summarizing our experience with short-term and long-term administration of ketoconazole in 14 patients with Cushing’s syndrome, we found that ketoconazole is able to inhibit cortisol biosyn-
thesis by blocking adrenal 118-hydroxylase and 17a-hydroxylase. However, this effect in our study was partially compensated by an increased pitui- tary ACTH secretion in the majority of the patients with pituitary-dependent Cushing’s disease. There- fore, only patients with Cushing’s syndrome due to an adrenal tumor or an ectopic ACTH syn- drome can be treated effectively with ketoconazole. In patients with pituitary-dependent hypercortisol- ism increased ACTH secretion overcomes, as a rule, the blocking effect on cortisol biosynthesis and induces a mineralocorticoid excess with hyper- secretion of 11-deoxycortisol and 11-deoxycorti- costerone.
Further cooperative studies should be planned in order to find out what proportion of patients with pituitary-dependent Cushing’s disease will have benefit of ketoconazole therapy, how long a positive effect of the drug may last, and whether there are any characteristics which would allow the prediction of an individual patient’s response.
Acknowledgments. We are indebted to Prof. Dr. O.A. Müller, Medical Department Innenstadt, University of Munich, for the determination of plasma ACTH levels of four patients, to Dr. G. Bauriedel, Medical Department I, Klinikum Grosshadern, University of Munich, for the disposal of serum and urine of two patients, to Mrs. B. Adelmann, Mrs. R. Joswig, and Mrs. M. Herrmann for their skilful technical assistance, and to Mrs. G. Schmitz and Mrs. S. Webeck for their help in preparing the manuscript.
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Received: July 1, 1988
Returned for revision : September 12, 1988 Accepted: November 17, 1988
Prof. Dr. D. Engelhardt Medizinische Klinik II Klinikum Grosshadern Marchioninistr. 15 D-8000 München 70