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Reduction of serum triglycerides and cholesterol by ethyl p-chlorophenoxyisobutyrate (CPIB)
Reduction
of Serum Triglycerides
and
Cholesterol by Ethyl p-Chlorophenoxyisobutyrate (CPIB)* MAURICE M.
BEST, M.D. and CHARLES H. DUNCAN, M.D. Louisville,
Kentucky
I
androsterone so that the daily dose was 33 or 49.5 mg. of androsterone. The patients were seen at an interval of either two or three weeks throughout the period of observation. They were instructed to continue their customary diets except that no food was to be taken between the evening meal and their visits to the laboratory the next morning. At each visit the patient was interviewed for evaluation of changes in clinical condition or possible side effects of the drug; weight was recorded and venous blood collected. Serum cholesterol was determined by the method of Abel1 et al.* and triglycerides, by a modification of the method of Van Handel and Zilversmit.9 Free fatty acid concentration in the plasma was deter-
N 1962 OLIVER’ reported that the oral administration of a combination of the weakly androgenic steroid androsterone and ethyl p-chlorophenoxyisobutyrate (CPIB) to patients with ischemic heart disease resulted in a reduction in serum cholesterol and triglycHellman and associates2 had previously erides. shown that androsterone was inactive orally but that it reduced serum cholesterol when given intramuscularly. It was thus initially postulated’ that in the above combination the role of the CPIB was to render the androsterone orally active. Subsequent studies3v4 have confirmed that this mixture does effect a reduction in serum cholesterol and triglycerides in the majority of hyperlipemic patients. The role of the androsterone in the mixture has been questioned, however, CPIB alone having been reported to have an effect on serum lipids similar to that of CPIB with androsterone.s-7 The following study explores in a systematic manner the relative effectiveness of CPIB with and without androsterone on serum cholesterol and triglycerides.
mined on approximately one third of the specimens by the method of Dole as modified by Trout and associates. lo Serum glutamic oxaloacetic @GOT) and pyruvic (SGPT) transaminases were determined on all blood specimens.
RESULTS The mean serum cholesterol and triglyceride concentrations of most but not all of the patients were reduced by the administration of CPIB with or As compared without androsterone (Table II). to the placebo period, CPIB resulted in a mean reduction of serum triglycerides of 31 per cent CPIB with and of cholesterol of 11 per cent. androsterone was not significantly more effective, the mean reduction in serum triglycerides being 34 per cent and in serum cholesterol 16 The per cent, compared to the placebo period. drug effects were noted within two or three weeks and were maintained throughout the period of administration. When the placebo was substituted for the active drug, serum
METHODS Ten patients (Table I) were studied for one year. Each received CPIB alone for one four-month period, CPIB with androsterone for a second period, and corn-oil placebo capsules of identical appearance for the third period; the order of the periods was randomized. The drugs were given in three divided doses in 250 mg. capsules, the total daily dosage being 1.5 gm. in 9 subjects and 2.25 gm. in the other (Case 1). With the combination of CPIB and androsterone, each capsule contained 5.5 mg. of
* From the Department of Medicine, University of Louisville School of Medicine, Louisville, Ky. This study was supported by Grant HE-01946, National Institutes of Health, U. S. Public Health Service. The ethyl p-chlorophenoxyisobutyrate with and without androsterone and the placebo capsules were generously provided by Ayerst Laboratories. 230
THE
AMERICAN
JOURNAL
OF CARDIOLOGY
Serum
Triglycerides
and Cholesterol
231 TABLE I
cholesterol and triglycerides returned to their pretreatment range within the two or three week interval between change in medication and the next visit. No consistent tendency to rebound above usual levels was noted. Plasma free fatty acids varied widely from observation to observation; the mean concentration during the placebo period was 448 MEq./L. No drug effect was observed, but it is possible that a moderate decrease was obscured by the presence in the plasma of CPIB, about 30 per cent of which would have been included in the free fatty acids by the method used. No consistent weight changes were noted during the study; mean weights of the patients at the end of the three periods were placebo, 161 lb.; CPIB with androsterone, 161 lb. ; and CPIB, 162 lb. No increase in serum transaminase levels resulted from treatment with either CPIB with androsterone or CPIB alone; mean levels of SGOT during placebo, CPIB with androsterone and CPIB periods were 25, 24 and 25 units, respectively, and of SGPT 17, 14 and 12 units. The only untoward clinical finding which may have been related to the drug administration in
Patient Data Casr
2
1
30 41
Sex
Diagnosis
M M
Hyperlipcmia, xanthoma Atherosclerotic heart disease, obesity, gouty arthritis Atherosclerotic heart disease, myocardial infarction Atherosclerotx heart disease, myocardial infarction, angina pectoris Hyperlipcmia Moderate hyperlipemia, strong family history of atherosclerotic vascular disease Atherosclerotic heart disease, myocardial infarction, congestive heart failure Atherosclerotic heart disease, osteoporosis Atherosclerotic heart disease, angina pectori8 Atherosclerotic heart disease, angina pectoris, myocardial infarction
3
51
M
4
69
F
5
6
33 47
M M
7
75
F
8 9
65 53
M M
10
36
M
this small series of patients was the occurrence of two episodes of gouty arthritis in Case 2. Although he had a pretreatment elevation of serum uric acid (8.8 mg./lOO ml.), his initial symptoms of gout appeared during the sixth week of administration of CPIB with androsterone. The drug was continued and the symptoms of gouty arthritis disappeared follow-
TABLE II Lipid Levels* of the Patients During Each of the Three Four-Month -------Serum
Case
Placebo 396 f54 294 f82 228 f36 225 f47 199 f16 183 f44 179 f56 140 f26 107 fll 93 f13
1 2 3 4 5 6 7 8 9 10 Mean
204
* Values are means f VOLUME 15,
FEBRUARY
SD. 1965
Triglycerides(mg./lOO ml.) CPIB plus Androsterone 265 f64 170 128 147 122 138 f32 137 f19 126
*105
71 112 109 f14 66 f8 91 116 __ 132 of the mean.
Treatment
Periods
Serum Cholesterol&---(mg./lOO ml.) CPIB
Placebo
315 f71 182 f26 160 f19 124 f21 150 f21 113 f37 101 f24 88 f13 74 f8 99 f13
443 f35 252 f29 295 f13 282 f19 313 f13 247 f9 264 f22 292 f19 423 f32 306 f9
140
312
CPIB plus Androsterone 352 f38 234 f35 265 f14 204 f13 270 f19 242 f17 185 &26 223 f13 357 f19 259 f13 259
CPIB 408 f61 257 14 264 57 198 f16 297 f16 239 f13 200 f19 227 f15 397 f8 269 f18 276
232
Best and Duncan
ing the administration of colchicine. The patient remained asymptomatic for six weeks and then experienced a second episode of gout which again responded to the administration of colchicine without cessation of the CPIB with androsterone. There was no further recurrence during the subsequent four month periods of placebo and of CPIB administration. In none of the patients studied was there evidence of enhancement of angina pectoris or congestive heart failure during periods of drug or placebo administration. All patients remained in generally the same clinical state throughout the study and experienced no more symptoms during drug periods than during those of placebo administration. DISCUSSION The results of this study support the conclusion that CPIB is an effective hypolipemic agent and that the addition of androsterone does not increase effectiveness. The greater reduction of triglycerides than of cholesterol is in agreement with the report that CPIB lowers principally the Sf’ 20-400 class of lipoproteins which are high in triglyceride content and has little effect on the Sf’ O-20 class which is high in cholesterol.” The mechanism by which CPIB produces a reduction in serum lipids is not presently known. The addition of CPIB to rat liver homogenates has been reported to inhibit the incorporation of mevalonic acid-2-Cl4 into cholesterol.‘? To what extent this in vitro effect may be related to In the the effect of CPIB in vivo is uncertain. rat as in man, CPIB produces a greater reduction of serum triglycerides than of cholesterol,13 suggesting that inhibition of cholesterol synthesis is not the primary effect of CPIB on lipid metabolism. A more pertinent area of investigation would be that of possible effects of CPIB on triglyceride metabolism, particularly in the liver which is the source of the serum Sf’ Clearly, further work 20-400 lipoproteins. needs to be done on the mechanism of action of CPIB before it can be recommended for wide clinical trial. Side e$kcts reported to result from the administration of CPIB or CPIB with androsterone include potentiation of the effects of anticoagulant drugs,14 gain in weight presumed to be due to fluid retention,6 transient elevations of serum glutamic oxaloacetic transaminasel and occasional nausea.15 None of the patients in this series was receiving anticoagulant therapy.
No consistent weight gain occurred, nor were elevations in serum transaminases encountered. None of the patients in this series experienced nausea or other digestive symptoms attributable to the drug, but 2 of 8 other patients we have treated did complain of episodes of nausea which may have been drug related. In Case 2 any relation of the episodes of gout to the drug is uncertain, although a similar occurrence has been reported.7 SUMMARY
Ethyl b-chlorophenoxyisobutyrate (CPIB) was administered alone and in combination with androsterone to 10 patients with elevations of serum cholesterol and/or triglycerides. Serum lipid levels during the two four-month treatment periods were compared to those during a period of placebo administration of similar duration, the order of the periods being randomized. As compared to the placebo period, a mean reduction in serum triglycerides and, to a lesser extent, cholesterol occurred during the administration of both CPIB alone and CPIB with androsterone. The addition of androsterone to the CPIB did not significantly enhance the hypolipemic activity of CPIB. No adverse effect or toxici1.y was encountered. REFERENCES 1,
OLIVER, M. F.: Reduction of serum-lipid and uric-acid levels by an orally active androsterone. Lancet, 1 : 1321, 1962. 2. HELLMAN, L., BRADLOW, H. L., ZUMOFF, B., FUKUSHIMA, D. K., and GALLAGHER, T. F. Thyroid-androgen interrelations and the hypoJ. Clin. cholesteremic effect of androsterone.
Endocrinol, 19: 936, 1959. 3. BERKOWITZ, D. Selective blood lipid reductions b) newer pharmacologic agents. Am. J. Cardiol.. 12: 834, 1963. 4. BEST, M. M. and DUNCAN, C. H. Effects of cholesterol-lowering drugs on serum triglycerides. J.A.M.A., 187: 37, 1964. 5. HELLMAN, L. et al. Reduction of cholesterol and lipids in man by ethylp-chlorophenoxyisobutyrate.
Ann. Int. Med., 59: 477, 1963. 6. OLIVER, M. F. Further observations on the effects of Atromid and of ethyl chlorophenoxyisobutyrate on serum lipid levels. J. Atheroscler. RH., 3: 427,
1963. 7. HOWARD, R. P., ALAUPOVIC, P., BRUSCO, 0. J. and FURMAN, R. H.
8.
Effects of ethyl chlorophenoxy-
isobutyrate alone or with androsterone ( Atromid) on serum lipids, lipoproteins and related metabolic parameters in normal and hyperlipemic subjects. J. Athcroscler. Res., 3: 482, 1963.
ABELL, L. L., LEVY, B. B., BRODIE, B. B. and KENDALL. F. E. A simDlified method for the estima-
tion of total cholesterol in serum and demonstraTHE AMERICAN JOURNAL OF CARDIOLOGY
Serum Triglycerides and Cholesterol y;02 of its specificity.
J. Biol. Chem., 195: 357,
9. VAN HANDEL, E. and ZILVERSMIT, D. B. Micromethod for the direct determination of serum triglycerides. J. Lab. Clin. Med., 50: 152, 1957. 10. TROUT, D. L., ESTES, E. H., JR. and FRIEDBERG, S. J. Titration of free fatty acids of plasma: A study of current methods and a new modification. J. Lipid Res., 1: 199, 1960. 11. STRISOWER, E. H. AND STRISOWER, B. The separate hypolipoproteinemic effects of dextrothyroxine and ethyl chlorophenoxyisobutyrate. J. Clin. Endocrinol., 24: 139, 1964. 12. AZARNOFF, D. L. and TUCKER, D. R. Studies on
VOLUME 15, FEBRUARY 1965
233
mechanism of action of clofibrate. Fed. Proc., 23: 552, 1964. 13. BEST, M. M. and DUNCAN, C. H. Hypoglyceridemic effect of ethyl-a-p-chlorophenoxyisobutyrate with and without androsterone. Circulation, 28: 690, 1963. 14. OLIVER, M. F. et al. Effect of Atromid and ethyl chlorophenoxyisobutyrate on anticoagulant requirements. Lance&.1 : 143, 1963. 15. GREEN, K. G., INMAN, W. H. W. and THORP, J. M. Multicentre trial in the United Kingdom and Ireland of a mixture of ethyl chlorophenoxyisobutyrate and androsterone (Atromid). J. Afhero&r. Res., 3: 593, 1963.
of Serum Triglycerides
and
Cholesterol by Ethyl p-Chlorophenoxyisobutyrate (CPIB)* MAURICE M.
BEST, M.D. and CHARLES H. DUNCAN, M.D. Louisville,
Kentucky
I
androsterone so that the daily dose was 33 or 49.5 mg. of androsterone. The patients were seen at an interval of either two or three weeks throughout the period of observation. They were instructed to continue their customary diets except that no food was to be taken between the evening meal and their visits to the laboratory the next morning. At each visit the patient was interviewed for evaluation of changes in clinical condition or possible side effects of the drug; weight was recorded and venous blood collected. Serum cholesterol was determined by the method of Abel1 et al.* and triglycerides, by a modification of the method of Van Handel and Zilversmit.9 Free fatty acid concentration in the plasma was deter-
N 1962 OLIVER’ reported that the oral administration of a combination of the weakly androgenic steroid androsterone and ethyl p-chlorophenoxyisobutyrate (CPIB) to patients with ischemic heart disease resulted in a reduction in serum cholesterol and triglycHellman and associates2 had previously erides. shown that androsterone was inactive orally but that it reduced serum cholesterol when given intramuscularly. It was thus initially postulated’ that in the above combination the role of the CPIB was to render the androsterone orally active. Subsequent studies3v4 have confirmed that this mixture does effect a reduction in serum cholesterol and triglycerides in the majority of hyperlipemic patients. The role of the androsterone in the mixture has been questioned, however, CPIB alone having been reported to have an effect on serum lipids similar to that of CPIB with androsterone.s-7 The following study explores in a systematic manner the relative effectiveness of CPIB with and without androsterone on serum cholesterol and triglycerides.
mined on approximately one third of the specimens by the method of Dole as modified by Trout and associates. lo Serum glutamic oxaloacetic @GOT) and pyruvic (SGPT) transaminases were determined on all blood specimens.
RESULTS The mean serum cholesterol and triglyceride concentrations of most but not all of the patients were reduced by the administration of CPIB with or As compared without androsterone (Table II). to the placebo period, CPIB resulted in a mean reduction of serum triglycerides of 31 per cent CPIB with and of cholesterol of 11 per cent. androsterone was not significantly more effective, the mean reduction in serum triglycerides being 34 per cent and in serum cholesterol 16 The per cent, compared to the placebo period. drug effects were noted within two or three weeks and were maintained throughout the period of administration. When the placebo was substituted for the active drug, serum
METHODS Ten patients (Table I) were studied for one year. Each received CPIB alone for one four-month period, CPIB with androsterone for a second period, and corn-oil placebo capsules of identical appearance for the third period; the order of the periods was randomized. The drugs were given in three divided doses in 250 mg. capsules, the total daily dosage being 1.5 gm. in 9 subjects and 2.25 gm. in the other (Case 1). With the combination of CPIB and androsterone, each capsule contained 5.5 mg. of
* From the Department of Medicine, University of Louisville School of Medicine, Louisville, Ky. This study was supported by Grant HE-01946, National Institutes of Health, U. S. Public Health Service. The ethyl p-chlorophenoxyisobutyrate with and without androsterone and the placebo capsules were generously provided by Ayerst Laboratories. 230
THE
AMERICAN
JOURNAL
OF CARDIOLOGY
Serum
Triglycerides
and Cholesterol
231 TABLE I
cholesterol and triglycerides returned to their pretreatment range within the two or three week interval between change in medication and the next visit. No consistent tendency to rebound above usual levels was noted. Plasma free fatty acids varied widely from observation to observation; the mean concentration during the placebo period was 448 MEq./L. No drug effect was observed, but it is possible that a moderate decrease was obscured by the presence in the plasma of CPIB, about 30 per cent of which would have been included in the free fatty acids by the method used. No consistent weight changes were noted during the study; mean weights of the patients at the end of the three periods were placebo, 161 lb.; CPIB with androsterone, 161 lb. ; and CPIB, 162 lb. No increase in serum transaminase levels resulted from treatment with either CPIB with androsterone or CPIB alone; mean levels of SGOT during placebo, CPIB with androsterone and CPIB periods were 25, 24 and 25 units, respectively, and of SGPT 17, 14 and 12 units. The only untoward clinical finding which may have been related to the drug administration in
Patient Data Casr
2
1
30 41
Sex
Diagnosis
M M
Hyperlipcmia, xanthoma Atherosclerotic heart disease, obesity, gouty arthritis Atherosclerotic heart disease, myocardial infarction Atherosclerotx heart disease, myocardial infarction, angina pectoris Hyperlipcmia Moderate hyperlipemia, strong family history of atherosclerotic vascular disease Atherosclerotic heart disease, myocardial infarction, congestive heart failure Atherosclerotic heart disease, osteoporosis Atherosclerotic heart disease, angina pectori8 Atherosclerotic heart disease, angina pectoris, myocardial infarction
3
51
M
4
69
F
5
6
33 47
M M
7
75
F
8 9
65 53
M M
10
36
M
this small series of patients was the occurrence of two episodes of gouty arthritis in Case 2. Although he had a pretreatment elevation of serum uric acid (8.8 mg./lOO ml.), his initial symptoms of gout appeared during the sixth week of administration of CPIB with androsterone. The drug was continued and the symptoms of gouty arthritis disappeared follow-
TABLE II Lipid Levels* of the Patients During Each of the Three Four-Month -------Serum
Case
Placebo 396 f54 294 f82 228 f36 225 f47 199 f16 183 f44 179 f56 140 f26 107 fll 93 f13
1 2 3 4 5 6 7 8 9 10 Mean
204
* Values are means f VOLUME 15,
FEBRUARY
SD. 1965
Triglycerides(mg./lOO ml.) CPIB plus Androsterone 265 f64 170 128 147 122 138 f32 137 f19 126
*105
71 112 109 f14 66 f8 91 116 __ 132 of the mean.
Treatment
Periods
Serum Cholesterol&---(mg./lOO ml.) CPIB
Placebo
315 f71 182 f26 160 f19 124 f21 150 f21 113 f37 101 f24 88 f13 74 f8 99 f13
443 f35 252 f29 295 f13 282 f19 313 f13 247 f9 264 f22 292 f19 423 f32 306 f9
140
312
CPIB plus Androsterone 352 f38 234 f35 265 f14 204 f13 270 f19 242 f17 185 &26 223 f13 357 f19 259 f13 259
CPIB 408 f61 257 14 264 57 198 f16 297 f16 239 f13 200 f19 227 f15 397 f8 269 f18 276
232
Best and Duncan
ing the administration of colchicine. The patient remained asymptomatic for six weeks and then experienced a second episode of gout which again responded to the administration of colchicine without cessation of the CPIB with androsterone. There was no further recurrence during the subsequent four month periods of placebo and of CPIB administration. In none of the patients studied was there evidence of enhancement of angina pectoris or congestive heart failure during periods of drug or placebo administration. All patients remained in generally the same clinical state throughout the study and experienced no more symptoms during drug periods than during those of placebo administration. DISCUSSION The results of this study support the conclusion that CPIB is an effective hypolipemic agent and that the addition of androsterone does not increase effectiveness. The greater reduction of triglycerides than of cholesterol is in agreement with the report that CPIB lowers principally the Sf’ 20-400 class of lipoproteins which are high in triglyceride content and has little effect on the Sf’ O-20 class which is high in cholesterol.” The mechanism by which CPIB produces a reduction in serum lipids is not presently known. The addition of CPIB to rat liver homogenates has been reported to inhibit the incorporation of mevalonic acid-2-Cl4 into cholesterol.‘? To what extent this in vitro effect may be related to In the the effect of CPIB in vivo is uncertain. rat as in man, CPIB produces a greater reduction of serum triglycerides than of cholesterol,13 suggesting that inhibition of cholesterol synthesis is not the primary effect of CPIB on lipid metabolism. A more pertinent area of investigation would be that of possible effects of CPIB on triglyceride metabolism, particularly in the liver which is the source of the serum Sf’ Clearly, further work 20-400 lipoproteins. needs to be done on the mechanism of action of CPIB before it can be recommended for wide clinical trial. Side e$kcts reported to result from the administration of CPIB or CPIB with androsterone include potentiation of the effects of anticoagulant drugs,14 gain in weight presumed to be due to fluid retention,6 transient elevations of serum glutamic oxaloacetic transaminasel and occasional nausea.15 None of the patients in this series was receiving anticoagulant therapy.
No consistent weight gain occurred, nor were elevations in serum transaminases encountered. None of the patients in this series experienced nausea or other digestive symptoms attributable to the drug, but 2 of 8 other patients we have treated did complain of episodes of nausea which may have been drug related. In Case 2 any relation of the episodes of gout to the drug is uncertain, although a similar occurrence has been reported.7 SUMMARY
Ethyl b-chlorophenoxyisobutyrate (CPIB) was administered alone and in combination with androsterone to 10 patients with elevations of serum cholesterol and/or triglycerides. Serum lipid levels during the two four-month treatment periods were compared to those during a period of placebo administration of similar duration, the order of the periods being randomized. As compared to the placebo period, a mean reduction in serum triglycerides and, to a lesser extent, cholesterol occurred during the administration of both CPIB alone and CPIB with androsterone. The addition of androsterone to the CPIB did not significantly enhance the hypolipemic activity of CPIB. No adverse effect or toxici1.y was encountered. REFERENCES 1,
OLIVER, M. F.: Reduction of serum-lipid and uric-acid levels by an orally active androsterone. Lancet, 1 : 1321, 1962. 2. HELLMAN, L., BRADLOW, H. L., ZUMOFF, B., FUKUSHIMA, D. K., and GALLAGHER, T. F. Thyroid-androgen interrelations and the hypoJ. Clin. cholesteremic effect of androsterone.
Endocrinol, 19: 936, 1959. 3. BERKOWITZ, D. Selective blood lipid reductions b) newer pharmacologic agents. Am. J. Cardiol.. 12: 834, 1963. 4. BEST, M. M. and DUNCAN, C. H. Effects of cholesterol-lowering drugs on serum triglycerides. J.A.M.A., 187: 37, 1964. 5. HELLMAN, L. et al. Reduction of cholesterol and lipids in man by ethylp-chlorophenoxyisobutyrate.
Ann. Int. Med., 59: 477, 1963. 6. OLIVER, M. F. Further observations on the effects of Atromid and of ethyl chlorophenoxyisobutyrate on serum lipid levels. J. Atheroscler. RH., 3: 427,
1963. 7. HOWARD, R. P., ALAUPOVIC, P., BRUSCO, 0. J. and FURMAN, R. H.
8.
Effects of ethyl chlorophenoxy-
isobutyrate alone or with androsterone ( Atromid) on serum lipids, lipoproteins and related metabolic parameters in normal and hyperlipemic subjects. J. Athcroscler. Res., 3: 482, 1963.
ABELL, L. L., LEVY, B. B., BRODIE, B. B. and KENDALL. F. E. A simDlified method for the estima-
tion of total cholesterol in serum and demonstraTHE AMERICAN JOURNAL OF CARDIOLOGY
Serum Triglycerides and Cholesterol y;02 of its specificity.
J. Biol. Chem., 195: 357,
9. VAN HANDEL, E. and ZILVERSMIT, D. B. Micromethod for the direct determination of serum triglycerides. J. Lab. Clin. Med., 50: 152, 1957. 10. TROUT, D. L., ESTES, E. H., JR. and FRIEDBERG, S. J. Titration of free fatty acids of plasma: A study of current methods and a new modification. J. Lipid Res., 1: 199, 1960. 11. STRISOWER, E. H. AND STRISOWER, B. The separate hypolipoproteinemic effects of dextrothyroxine and ethyl chlorophenoxyisobutyrate. J. Clin. Endocrinol., 24: 139, 1964. 12. AZARNOFF, D. L. and TUCKER, D. R. Studies on
VOLUME 15, FEBRUARY 1965
233
mechanism of action of clofibrate. Fed. Proc., 23: 552, 1964. 13. BEST, M. M. and DUNCAN, C. H. Hypoglyceridemic effect of ethyl-a-p-chlorophenoxyisobutyrate with and without androsterone. Circulation, 28: 690, 1963. 14. OLIVER, M. F. et al. Effect of Atromid and ethyl chlorophenoxyisobutyrate on anticoagulant requirements. Lance&.1 : 143, 1963. 15. GREEN, K. G., INMAN, W. H. W. and THORP, J. M. Multicentre trial in the United Kingdom and Ireland of a mixture of ethyl chlorophenoxyisobutyrate and androsterone (Atromid). J. Afhero&r. Res., 3: 593, 1963.