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 Officer 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.