Suppression of Postpartum Lactation with Furosemide

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					21 Februarie 1976                             A    MEDIESE      TVDSKRIF                                                 251

         Suppression of Postpartum Lactation with Furosemide
                     D. C. COMINOS,         A. VAN DER WALT,              A. J. L. VAN ROOYE

                            SUMMARY                            of 2 Slow-K tablets 3 times a day was given. On the
                                                               second day, a well-fitting and firm brassiere was sub-
  A regimen of furosemide and moderate restriction of fluid    stituted in place of the binder. Subsequent medication
  intake was followed in 120 postpartum women to suppress      consisted of 1 furosemide tablet (40 mg) early in the
  lactation. The methods and results are presented, and pos-   morning together with 2 Slow-K tablets 3 times a day
  sible mechanisms whereby furosemide may suppress lac-        for the next 4 days. For as long as the breasts remained
  tation are discussed.                                        firm, fluid restriction was maintained. The breasts were
                                                               handled as seldom as possible. A daily record was kept
                                                               by the ward staff and the attending obstetrician of the
  S. Air. med. J., 50, 251 (1976).
                                                               state of the patient's breasts, noting whether there was
                                                               engorgement, slight engorgement or none at all. Patients
At the Maternity Unit of the South Rand Hospital in
                                                               were closely observed for any elevation of temperature.
Johannesburg we have been disenchanted with methods
                                                               A final assessment of the state of the breasts was made on
used for the suppression of lactation for some time. The
                                                               the day of the patient's discharge, usually on the 5th
suggestion by MacDonald and O'Driscoll' that no medi-          day after starting the treatment.
cation is necessary for the suppression of lactation has
not been favoured in our department. Hormonal inhibi-
tion by oestrogens or an oestrogen-androgen combination        FoUow-up
may enhance the risk of thrombo-embolic complications.
for certain types of patients in the puerperium.' We              The patients were asses ed at the postnatal clinic 6
have also noted that a significant number of patients          weeks later or by personal communication with those
who were treated with hormones returned before the             patients who did not come to the clinic. The breasts
postnatal checkup with secondary postpartum bleeding           were examined to note the consistency and whether
and rebound lactation. We certainly do not agree with          t~ere were any signs of lactation. In addition the pa-
the statement by Rolland and Schellekens' that restric-        tIents were asked whether they had had any trouble with
tion of fluid intake, supplemented by diuretic agents, is      their breasts since leaving hospital and whether any
ineffective in suppressing lactation. For the past 9 months    treatment by their family doctor had been required.
we have used the latter method and the results have been
encouraging and acceptable to the patients as well as to                               RESULTS
the nursing staff who participated in the trial.
                                                               ~o p~tient complained of any discomfort caused by the
                                                               dIUreSIS and none showed any signs of dehydration. Ele-
                 PATIENTS AND METHODS                          vation .of temperature was not encountered in any of
                                                               the patIents. The results of the treatment are summarised
One hundred and twenty patients took part in the trial         in Table I.
which included those who elected not to breast-feed at all
once the baby was born and also those in whom lactation               TABLE I. RESULTS OF TREATMENT DURING
was already established for 1 - 3 days. The average dura-               HOSPITALISATION AND AFTER 6 WEEKS
tion of stay in hospital of the patients was 5 days. In
the early morning following delivery, or on the next mor-      1 - 5 days in hospital
ning in those who already lactated, 20 mg furosemide              Total number of patients ..                   120
(Lasix, Hoechst) was injected intramuscularly. The breasts        No lactation                                   52   (43,4%)
were bound comfortably tight with a towel and safety              Slight lactation with no pain or discomfort    66   (55,0%)
pins and the patient was instructed to drink no tea or            Lactation with pain and engorgement '"          2   (1,6%)
coffee, in particular, and to limit her fluid intake in
such a way that there would be no excessive thirst. At         After 6 weeks
the same time potassium supplementation in the form              Number of patients followed-up                 100
                                                                 Completely successful                           91
                                                                 Lactation not causing trouble .                  7
Department of Gynaecology and Obstetrics, University of the      Lactation requiring additional treatment         2
  Witwatersrand, and South Rand Hospital, Johannesburg
D. C. COMINOS, B.SC., DIP. MID. C.o.G. (S.A.), M.R.C.O.G.,
  Senior Specialist                                                                  DISCUSSION
A. VAN DER WALT, M.B. B.CH-, F.C.O.G. (S.A.), Senior Medical
A. J. L. VAN ROOYEN, CH. M., DIP. O. & G., Senior Consultant   Furosemide was first used in our department in small
  and Head of Department                                       doses and usually as a single dose to relieve severe breast
Date received:   4 August   1975.                              engorgement in nursing mothers. We noticed that a
252                                           A   MEDICAL         JOUR        AL                                21 February 1976

single oral dose of 40 mg was ufficient to relieve the          as phenothiazine, ampbetamine and methyldopa may
engorgement without 'drying up the milk'. If the dosage         diminish the activity of this factor.
was increased, the mothers complained that the milk was            Gachev' subjected lactating rabbits to dehydration by
decreasing in quantity. On this basis we decided to attempt     injecting furosemide and by administration of large a-
to inhibit lactation altogether by increasing the dose to a     mounts of sodium chloride. He observed a decrease in tbe
standard quantity.                                              milk yield on the next day, accompanied by a higher
                                                                density of the milk and a decrease in the lactose concen-
                                                                tration. Lactose production depends exclusively on pro-
Pharmacology of Furosemide                                      lactin and the amount of mammary lactose synthesi ed
                                                                has been used as an indicator for the amount of prolactin
   Furosemide acts by reducing the resorption of sodium         released from the anterior pituitary. Gachev therefore
and water at the levels of the proximal convoluted tubule,      concluded that the secretion of prolactin is definitely in-
the ascending liml5 of the loop of Henle, and the distal        hibited under conditions of dehydration. It is possible that
convoluted tubule. The action on the loop of Henle is tbe       the dehydration may enhance the activity of prolactin-inbi-
most important. With oral administration, the onset of          biting factor. It would be interesting to know whether the
action occurs after 30 minutes, peak action being achieved      increased output of antidiuretic bormone during dehy-
within 2 hours, and diuresis continues for about 4 - 5          dration may not competitively block the secretion of
hours. With parenteral administration, the onset of ac-         oxytocin from the posterior pituitary. Galactose forma-
tion is even more rapid.                                        tion has also been observed in animals after pharmaco-
                                                                 logical doses of oxytocin had been given. When oxytocin
                                                                action is blocked by injected or endogenously released
Mechanism of Suppression of Lactation by Furo-                   catecholamines, women fail to lactate."
semide                                                              Another explanation for inhibition of lactation may be
                                                                 that the diuresis restricts the flow of extracellular fluid
                                                                 entering the mammary gland for the purpose of milk
   The exact mechanism(s) whereby furosemide inhibits
                                                                 formation. Other substances' may interfere with drug-
lactation is not fully understood. Increasing the fluid
                                                                 induced suppression of lactation. In experimental animals
intake may lower pituitary prolactin secretion and serum
                                                                 theophylline has been found' to stimulate prolactin secre-
prolactin levels: It may therefore be that the sudden and
                                                                 tion, therefore tea and coffee should be temporarily ex-
intensified diuresis bas a direct action on tbe hypothala-
                                                                 cluded from the diet. Certain soft drinks containing caf-
mic-pituitary axis, thus affecting the endocrine mechanisms
                                                                 feine should also be temporarily prohibited. Tranquilli-
taking part in the maintenance of lactation.
                                                                 sers such as phenothiazines, meprobamate and reserpine
   An afferent neural reflex pathway for release of prolactin
                                                                 may also promote lactation by decreasing the activity of
and oxytocin becomes operative wben sensory nerve en-
                                                                 prol.actin-inbibiting factor and thereby increasing pro-
dings in tbe areola and nipple are stimulated by suck-           lactm secretion.
ling or manipulation of the breast. Nerve impulses gene-
                                                                    The inhibition of lactation by furosemide might be
rated in the nipple are transmitted to the mesencephalon.
                                                                 brought about in many different ways. However, two
From the mesencephalon the stimuli are transmitted to the
                                                                 possibilities are that furosemide might inhibit prolactin
hypothalamic regions which regulate the release of pro-
                                                                 secretion or that it might block the effect of prolactin
lactin and oxytocin. Surgical transection of the human            peripherally.
pituitary stalk induces chronic prolactin secretion and it
may therefore be deduced that tbe secretion of prolactin
 by tbe posterior pituitary is regulated by the hypotbalamus                                 REFERENCES
whicb exerts a continuous inhibitory influence upon pro-
lactin secretion. The substance known as prolactin-in-          ~: ~ff~~a~~~lt 0,. ~n~ ~;~::~C~l1, a~' g;s~5)~L;nc(lt9~5: 6~~;t.   med. J ..
 hibiting factor has not yet been isolated in man. In rats
                                                                3. :O~";~~: R. and Schellekens, L. (1973): J. Obstet. Oynaec. Brit. Cwlth.
the activity of prolactin-inhibiting factor is manifested
                                                                4. Buckman. M. T., Kammsky, N., Cnnway, M. and Peake O. T.
only when sufficient extracellular calcium is available.           (1973): Clin Res.. 21. 250.
Certain drugs such as L-dopa and ergocornine may in-            5. Oachev, P. O. (1968): ArzneimitteJ-Fnrsch., 18, 738.
                                                                6. Vorherr. H. (1971): Acta endocr. (Kbh). 67. supp!. 154. pp. 5 - 3
crease prolactin-inhibiting factor activity, and others such    7. Idem (1972): Postgrad. Med., 52, 145.