Methyclothiazide / reserpine Pregnancy and Breastfeeding Warnings
Brand names: Diutensen-R
Methyclothiazide / reserpine Pregnancy Warnings
Reserpine-methyclothiazide has been assigned to pregnancy category C by the FDA. Animal studies have revealed evidence of teratogenicity after doses of reserpine 125 to 250 times the maximum recommended human dose (MRHD, on a per kg basis) were given to rats. Abnormalities included anophthalmia, absence of the axial skeleton, and hydronephrosis. Pregnancy in rabbits was interrupted when doses of reserpine 10 times the MRHD were given early or late in pregnancy. Animal data have failed to reveal evidence of teratogenicity associated with methyclothiazide. Some retrospective reviews have shown an increased risk of malformations associated with thiazide diuretics. There are no controlled data from human pregnancy. Reserpine-methyclothiazide should only be given during pregnancy when there are no alternatives and benefit outweighs risk.
There are three relevant sources of information regarding the use of reserpine during human pregnancy.
In one case report, a stillborn female was born at gestation week 30 to a hypertensive, 30-year-old mother who had taken reserpine from days 13 to 41. Abnormalities included cleft lip and palate and bilateral anophthalmia, marked scoliosis, a thoracolumbar open defect, and diaphragmatic agenesis. The mother had also been exposed to tobacco and ampicillin.
Cziezel summarized the Hungarian experience with reserpine from 1980 to 1984. During this period, 52 of 6,227 pregnant women were exposed to reserpine. Neither the total group nor subgroups of congenital anomalies indicated a significant increase associated with reserpine treatment during pregnancy. There was no evidence of a congenital reserpine syndrome.
Of 50,282 mother-child pairs monitored by the Collaborative Perinatal Project, 48 had first trimester exposure to reserpine and 475 had exposure to reserpine at anytime during pregnancy. Of the 48, 4 defects (8%) were observed, which was more than expected. Of the 475, microcephaly (7), hydronephrosis (3), inguinal hernia (12), and hydroureter (3), were observed. None of these anomalies occurred significantly more than expected.
Thiazides readily cross the human placenta, with umbilical cord blood thiazide levels approximately equivalent to maternal plasma thiazide levels.
Of the 50,282 mother-child pairs in the study mentioned above, 233 were exposed to thiazide or related diuretics during the first trimester. An increased risk of malformations was found for thiazide diuretics, although the fact that the population studied had underlying cardiovascular disease makes implication of drug use alone difficult. Use of thiazides after the first trimester does not seem to carry this risk. Thiazide diuretics may, however pose metabolic risks to the mother and fetus (hyponatremia, hypokalemia, thrombocytopenia, hyperglycemia), and may have a direct effect on smooth muscle, resulting in inhibition of labor.
The Michigan Medicaid surveillance study showed no association between reserpine or thiazide diuretics and congenital defects (written communication, Franz Rosa, MD, Food and Drug Administration, 1994). Of 229,101 completed pregnancies between 1985 and 1992, 15 were exposed to reserpine at some time during the first trimester, and 42 were exposed to the drug at any time during pregnancy. No birth defects were observed. Regarding thiazide diuretics, this report is a summary of two studies, one in which 390 of 104,000 pregnant women from 1980 to 1983, and one in which 567 of 229,000 pregnant women from 1985 to 1992 received a related drug, hydrochlorothiazide (HCTZ). In the first study 28 total defects and 6 cardiovascular defects were observed (25 and 4 were expected, respectively). In the second study, 24 total defects and 7 cardiovascular defects were observed (22 and 6 were expected, respectively). Cleft palate was not observed in either study. These data do not support an association between reserpine or HCTZ and congenital defects. These data are considered pertinent to other thiazide diuretics.
Cases of neonatal thrombocytopenia associated with antepartum administration of thiazide diuretics have been reported.
Methyclothiazide / reserpine Breastfeeding Warnings
Reserpine is excreted into human milk. There are no reports of adverse effects on the nursing infant. There is a report of galactorrhea associated with reserpine.
Thiazides are excreted into human milk in low concentrations. While a rare case of thrombocytopenia has been reported in one nursing infant whose mother was taking a related drug, chlorothiazide, adverse effects in the nursing infant are unlikely. However, the manufacturer recommends that due to the potential for serious adverse reactions in nursing infants, a decision should be made to discontinue nursing or discontinue the methyclothiazide, taking into account the importance of the drug to the mother.
References for pregnancy information
- Lammintausta R, Erkkola R, Eronen M (1978) "Effect of chlorthiazide treatment on renin-aldosterone system during pregnancy." Acta Obstet Gynecol Scand, 57, p. 389-92
- Goldman JA, Neri A, Ovadia J, Eckerling B, Vries A, de (1969) "Effect of chlorothiazide on intravenous glucose tolerance in pregnancy." Am J Obstet Gynecol, 105, p. 556-60
- Bird CC, Reeves BD (1969) "Effect of diuretic administration on urinary estriol levels in late pregnancy." Am J Obstet Gynecol, 105, p. 552-5
- Aneckstein AG, Weingold AB (1966) "Chlorothiazide-induced hepatic coma in pregnancy." Am J Obstet Gynecol, 95, p. 136-7
- Anderson GG, Hanson TM (1974) "Chronic fetal bradycardia: possible association with hypokalemia." Obstet Gynecol, 44, p. 896-8
- Heinonen O, Shapiro S; Kaufman DW ed., Slone D (1977) "Birth Defects and Drugs in Pregnancy." Littleton, MA: Publishing Sciences Group, Inc., p. 297
- Rodriguez SU, Sanford LL, Hiller MC (1964) "Neonatal thrombocytopenia associated with ante-partum administration of thiazide drugs." N Engl J Med, 270, p. 881-4
- Czeizel A (1988) "Reserpine is not a human teratogen." J Med Genet, 25, p. 787
- Pauli RM, Pettersen BJ (1986) "Is reserpine a human teratogen?" J Med Genet, 23, p. 267-8
- Mackay EV, Khoo SK (1969) "Clinical and laboratory study of a new diuretic agent ("vectren") in pregnancy: a comparison with a diuretic agent in current use ("enduron")." Med J Aust, 1, p. 607-12
- Walker JL (1966) "Methyclothiazide in excessive weight gain and edema of pregnancy." Obstet Gynecol, 27, p. 247-51
- Mackay EV, Khoo SK, Adsett G, Zymanska S (1969) "A clinical study of the effects of an aldosterone antagonist (Aldactone-A) and a thiazide diuretic (Enduron) in pregnancy." Aust N Z J Obstet Gynaecol, 9, p. 188-95
- Zuspan FP, Bell JD, Barnes AC (1960) "Balance-ward and double-blind diuretic studies during pregnancy." Obstet Gynecol, 16, p. 543-9
- Tatum HJ, Waterman EA (1961) "The prophylactic and therapeutic use of the thiazides in pregnancy." GP, 24, p. 101-5
- Weseley AC, Douglas GW (1962) "Continuous use of chlorothiazide for prevention of toxemia of pregnancy." Obstet Gynecol, 19, p. 355-8
- Gray MJ (1968) "Use and abuse of thiazides in pregnancy." Clin Obstet Gynecol, 11, p. 568-78
- Watt JD (1960) "Oral diuretics in pregnancy toxaemia." Br Med J, 1, p. 1807
- Sibai BM, Grossman RA, Grossman HG (1984) "Effects of diuretics on plasma volume in pregnancies with long-term hypertension." Am J Obstet Gynecol, 150, p. 831-5
- Shoemaker ES, Gant NF, Madden JD, MacDonald PC (1973) "The effect of thiazide diuretics on placental function." Tex Med, 69, p. 109-15
- Garnet JD (1963) "Placental transfer of chlorothiazide." Obstet Gynecol, 21, p. 123-5
- Mulley BA, Parr GD, Pau WK, Rye RM, Mould JJ, Sidle NC (1978) "Placental transfer of chlorthalidone and its elimination in maternal milk." Eur J Clin Pharmacol, 13, p. 129-31
- Menzies DN (1964) "Controlled trial of chlorothiazide in treatment of early pre-eclampsia." Br Med J, 1, p. 139-42
- Ladner CN, Pearson JW, Herrick CN, Harrison HE (1964) "The effect of chlorothiazide on blood glucose in the third trimester of pregnancy." Obstet Gynecol, 23, p. 555-60
- Harley JD, Robin H, Robertson SE (1964) "Thiazide-induced neonatal haemolysis?" Br Med J, 1, p. 696-7
- Leikin SL (1964) "Thiazide and neonatal thrombocytopenia." N Engl J Med, 271, p. 161
- Prescott LF (1965) "Neonatal thrombocytopenia and thiazide drugs." J Pediatr, 67, p. 681-2
- Finnerty FA (1964) "Thiazide and neonatal thrombocytopenia." N Engl J Med, 271, p. 160-1
- Pritchard JA, Walley PJ (1961) "Severe hypokalemia due to prolonged administration of chlorothiazide during pregnancy." Am J Obstet Gynecol, 81, p. 1241-4
- Crosland DM, Flowers CE (1963) "Chlorothiazide and its relationship to neonatal jaundice." Obstet Gynecol, 22, p. 500-4
- Minkowitz S, Soloway HB, Hall JE, Yermakov V (1964) "Fatal hemorrhagic pancreatitis following chlorothiazide administration in pregnancy." Obstet Gynecol, 24, p. 337-42
- "Product Information. Diutensen-R (methyclothiazide-reserpine)." Wallace Laboratories
References for breastfeeding information
- Werthmann MW, Krees SV (1972) "Excretion of chlorothiazide in human breast milk." J Pediatr, 81, p. 781-3
- Miller ME, Cohn RD, Burghart PH (1982) "Hydrochlorothiazide disposition in a mother and her breast-fed infant." J Pediatr, 101, p. 789-91
- Ananth J (1978) "Side effects in the neonate from psychotropic agents excreted through breast-feeding." Am J Psychiatry, 135, p. 801-5
- Mulley BA, Parr GD, Pau WK, Rye RM, Mould JJ, Sidle NC (1978) "Placental transfer of chlorthalidone and its elimination in maternal milk." Eur J Clin Pharmacol, 13, p. 129-31
- (2001) "Product Information. Enduron (methyclothiazide)." Abbott Pharmaceutical
- "Product Information. Diutensen-R (methyclothiazide-reserpine)." Wallace Laboratories
Further information
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.