Last update July 25, 2022

Sodium Nitroprusside

High Risk

Poorly safe. Evaluate carefully. Use safer alternative or interrupt breastfeeding 3 to 7 T ½ (elimination half-lives). Read the Comment.

Nitroprusside (NP) is a powerful arteriovenous vasodilator that decreases peripheral vascular resistance, and is used in hypertensive crises (Pediamecum 2016). It is metabolized producing nitric oxide (vasodilator) and cyanide which is metabolized to thiocyanate which is eliminated by urine (AEMPS 2017, FDA 2017) and can be toxic if the doses have been high or very prolonged (Moffett 2008), especially if there is kidney or liver failure. Administration via intravenous infusion continues for a few hours (usually less than 3 days). After that time, plasma cyanide levels should be monitored so that they do not exceed 1 microgram/mL and thiocyanate levels remain below 80 nanograms/mL.

Sine the last update we have not found published data on Nitroprusside excretion in breastmilk.

The rapid elimination half-life of nitroprusside (T½ of 2 minutes) makes it very unlikely it will be excreted in breastmilk and, in addition, its oral bioavailability is almost zero, therefore it would not be absorbed by the infant's intestine.

Cyanide and thiocyanate have a T ½ of 7 hours and of 3 to 7 days respectively (Hale, Kirsten 1998, Schulz 1984). Thiocyanate also has a 100% oral bioavailability. Both, but especially thiocyanate, would be excreted in breastmilk.

Thiocyanate is a common component of breastmilk (Kirk 2007, Funderburk 1967) with concentrations dependent on smoking (Meberg 1979), exposure to certain industrial products, the consumption of certain foods (cassava or manioc, some pulses and almonds) and intake of medication such as nitroprusside. (Dorea 2004, Laurberg 2004)

There is low excretion in breastmilk, milk levels being lower than plasma ones, with a milk/plasma index of 0.4 to 0.7. (Dorea 2002, Funderburk 1967)

Nitroprusside is used in Pediatrics even in premature infants, especially in serious situations (Deliu 2018, Pediamecum 2016, Drover 2015, Hammer 2015, Clark 2006, Cachat 2004, Benitz 1985) with good tolerance and very low and infrequent toxicity if normal doses are respected. (Drover 2015, Hammer 2015, Thomas 2009, Benitz 1985)

Although the possibility that thiocyanate may interfere with thyroid function has been put forward (Lee 2017, Kirk 2007, Laurberg 2004), other authors have not found this link. (Leung 2012).

In summary, nitroprusside has good tolerance in pediatrics and is not likely to be eliminated in breastmilk or absorbed orally; the risk to the infant comes from the potential toxicity of its cyanogenic metabolites. Breastmilk contains thiocyanate and only if a breastfeeding mother has been treated with high doses or over many days with nitroprusside is it likely that the levels of thiocyanate in breastmilk would be high enough to cause problems in the infant. In cases of prolonged treatment, the plasma levels of cyanide and thiocyanate in the mother should be monitored as well as the appearance of clinical symptoms in the infant.


Suggestions made at e-lactancia are done by APILAM team of health professionals, and are based on updated scientific publications. It is not intended to replace the relationship you have with your doctor but to compound it. The pharmaceutical industry contraindicates breastfeeding, mistakenly and without scientific reasons, in most of the drug data sheets.

Jose Maria Paricio, Founder & President of APILAM/e-Lactancia

Your contribution is essential for this service to continue to exist. We need the generosity of people like you who believe in the benefits of breastfeeding.

Thank you for helping to protect and promote breastfeeding.

José María Paricio, founder of e-lactancia.

Other names

Sodium Nitroprusside in other languages or writings:


Main tradenames from several countries containing Sodium Nitroprusside in its composition:


Variable Value Unit
Oral Bioavail. NP: ≈ 0 / TC: 100 %
Molecular weight NP 298 daltons
VD NP - / TC: 0.25 l/Kg
pKa NP: 3.3 -
Tmax NP: 0.03 hours
NP: 0.03 / TC: 72 -168 hours
M/P ratio NP - / TC: 0.4 - 0.7 -


  1. Hale TW. Medications & Mothers' Milk. 1991- . Springer Publishing Company. Available from Consulted on March 17, 2022 Full text (link to original source)
  2. Deliu AG, Sanneerappa PBJ, Franklin O, Letshwiti J. Sodium nitroprusside, a lifesaving treatment for neonatal hypertension: an Irish experience. BMJ Case Rep. 2018 Abstract
  3. AEMPS. Nitroprusiato. Ficha técnica. 2017 Full text (in our servers)
  4. FDA (Exela). Nitroprusside. Drug Summary. 2017 Full text (in our servers)
  5. Lee SY, McCarthy AM, Stohl H, Ibrahim S, Jeong C, Braverman LE, Ma W, He X, Mestman JH, Schuller KE, Jahreis KA, Pearce EN, Leung AM. Urinary Iodine, Perchlorate, and Thiocyanate Concentrations in U.S. Lactating Women. Thyroid. 2017 Abstract
  6. Pediamécum-Comité de Medicamentos de la Asociación Española de Pediatría.. Nitroprusiato sódico Pediamécum 2016 Full text (link to original source) Full text (in our servers)
  7. Hammer GB, Lewandowski A, Drover DR, Rosen DA, Cohane C, Anand R, Mitchell J, Reece T, Schulman SR. Safety and efficacy of sodium nitroprusside during prolonged infusion in pediatric patients. Pediatr Crit Care Med. 2015 Abstract
  8. Drover DR, Hammer GB, Barrett JS, Cohane CA, Reece T, Zajicek A, Schulman SR. Evaluation of sodium nitroprusside for controlled hypotension in children during surgery. Front Pharmacol. 2015 Abstract
  9. Leung AM, Braverman LE, He X, Schuller KE, Roussilhes A, Jahreis KA, Pearce EN. Environmental perchlorate and thiocyanate exposures and infant serum thyroid function. Thyroid. 2012 Abstract
  10. Thomas C, Svehla L, Moffett BS. Sodium-nitroprusside-induced cyanide toxicity in pediatric patients. Expert Opin Drug Saf. 2009 Abstract
  11. Moffett BS, Price JF. Evaluation of sodium nitroprusside toxicity in pediatric cardiac surgical patients. Ann Pharmacother. 2008 Abstract
  12. Kirk AB, Dyke JV, Martin CF, Dasgupta PK. Temporal patterns in perchlorate, thiocyanate, and iodide excretion in human milk. Environ Health Perspect. 2007 Abstract
  13. Clark RH, Bloom BT, Spitzer AR, Gerstmann DR. Reported medication use in the neonatal intensive care unit: data from a large national data set. Pediatrics. 2006 Abstract
  14. Dorea JG. Maternal thiocyanate and thyroid status during breast-feeding. J Am Coll Nutr. 2004 Abstract
  15. Laurberg P, Nøhr SB, Pedersen KM, Fuglsang E. Iodine nutrition in breast-fed infants is impaired by maternal smoking. J Clin Endocrinol Metab. 2004 Abstract
  16. Cachat F, Bogaru A, Micheli JL, Lepori D, Guignard JP. Severe hypertension and massive proteinuria in a newborn with renal artery stenosis. Pediatr Nephrol. 2004 Abstract
  17. Dorea JG. Iodine nutrition and breast feeding. J Trace Elem Med Biol. 2002 Abstract Full text (link to original source) Full text (in our servers)
  18. Kirsten R, Nelson K, Kirsten D, Heintz B. Clinical pharmacokinetics of vasodilators. Part II. Clin Pharmacokinet. 1998 Abstract
  19. Benitz WE, Malachowski N, Cohen RS, Stevenson DK, Ariagno RL, Sunshine P. Use of sodium nitroprusside in neonates: efficacy and safety. J Pediatr. 1985 Abstract
  20. Schulz V. Clinical pharmacokinetics of nitroprusside, cyanide, thiosulphate and thiocyanate. Clin Pharmacokinet. 1984 Abstract
  21. Meberg A, Sande H, Foss OP, Stenwig JT. Smoking during pregnancy--effects on the fetus and on thiocyanate levels in mother and baby. Acta Paediatr Scand. 1979 Jul;68(4):547-52. Abstract
  22. Funderburk CF, Van Middlesworth L. Effect of lactation and perchlorate on thiocyanate metabolism. Am J Physiol. 1967 Abstract

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