Metoclopramide and breast feeding: transfer into milk and the newborn

Investigation of the effect of metoclopramide on proliferation signal molecules in breast tissue

Metoclopramide (MCP) is a drug that has been widely used in recent years due to its hyperprolactinaemia effect on mothers during breastfeeding. The aim of this study was to investigate the proliferative changes that MCP may cause in the maternal breast tissue. In this study, 18 Wistar albino young-adult breastfeeding mothers with their offspring were divided into three groups: control group, low-dose MCP-applied group and high-dose MCP-applied group. The experiment was carried out during the lactation period and at the end of 21 days. Prolactin, BrdU and Ki-67 breast tissue distributions were evaluated by immunohistochemistry, and tissue levels were evaluated biochemically by the ELISA method. According to ELISA and immunohistochemistry results in breast tissue, there was no significant difference between Ki-67 and BrdU results in all groups. Metoclopramide did not change the expression of proliferation molecules Ki-67 and BrdU in breast tissue. These results suggested that while metoclopramide increases breast proliferation, it does not have the risk of transforming the tissue into a tumour.

Efficacy and Safety of Domperidone and Metoclopramide in Breastfeeding: A Systematic Review and Meta-Analysis

Objectives: To evaluate the efficacy and safety of domperidone and metoclopramide used by breastfeeding women. Methods: A systematic literature search retrieved citations from PubMed, Embase, The Cochrane Library, Medline, EBSCO, Web of Science, ClinicalTrials.gov (from inception to January, 2021) and bibliographies of known articles. Randomized controlled trials exploring the effects of domperidone and metoclopramide in breastfeeding women with term and preterm infants experiencing adequate or low milk supply were identified. Human milk volume and maternal side effects were presented as mean difference (MD) or relative risks (RR) with 95% confidence intervals (CI). Results: Sixteen trials involving 729 women were included in the qualitative analysis and 14 trials involving 607 women were included in the meta-analysis. In mothers of preterm infants with low milk supply, domperidone demonstrated a significant increase in daily human milk volume (MD = 90.53 mL/day, 95% CI [65.42 to 115.64], I² = 9%). However, metoclopramide did not show significant difference in daily human milk volume in women with preterm infants (MD = -1.14 mL/day, 95% CI [-31.42 to 29.14], I² = 0%). No differences in maternal side effects were noted with domperidone (RR = 1.20, 95% CI [0.74 to 1.97], I² = 0%) or metoclopramide (RR = 1.05, 95% CI [0.52 to 2.11], I² = 27%) in women with preterm infants. Regarding the women with term infants, there were insufficient data in the current review. Conclusions: Domperidone can be used to treat low milk supply in women with preterm infants without significant side effects based on the current review. More evidence exploring the efficacy and safety of domperidone and metoclopramide are still needed for breastfeeding women in the future.

Migraine: navigating the hormonal minefield

Migraine affects 959 million people worldwide,1 with the highest prevalence being in women of childbearing age. The interplay between female hormones and migraine can be a challenging area to navigate since issues relating to pregnancy, contraception and the menopause are often out of the neurology comfort zone. This review aims to help the neurologist to manage women with migraine, from menarche to menopause.

[Medications in breastfeeding: what evidence is there?]

Breastfeeding plays a fundamental role in the benefits for the health of the newborn child and the nursing mother. The use of medications during breastfeeding is a relevant issue, by virtue of the frequent need for pharmacological treatment in the postpartum period. The scope of this article was to conduct a review of the literature regarding the efficacy and safety of medications used during the breastfeeding period. A search was conducted in the PubMed (National Library of Medicine), ScienceDirect and Biblioteca Virtual em Saúde (BVS) databases for articles published in Portuguese, English and Spanish in the period from 1981 to 2016. This review discusses the risk of the use of medications during lactation and the effects that they may have on the breastfed infant. Few medications are contraindicated and others require care due the risk of adverse effects on breastfed infants or in the suppression of breast milk volume. Therefore, the dissemination of updated information for the health professional to adequately assess the risks and the benefits of the use of medications during breastfeeding is of vital importance, thereby contributing to avoid early weaning.

What Evidence Do We Have for Pharmaceutical Galactagogues in the Treatment of Lactation Insufficiency?-A Narrative Review

Inadequate breast milk supply is a frequently reported reason for early discontinuation of breastfeeding and represents a critical opportunity for intervening to improve breastfeeding outcomes. For women who continue to experience insufficient milk supply despite the utilisation of non-pharmacological lactation support strategies, pharmacological intervention with medications used to augment lactation, commonly referred to as galactagogues, is common. Galactagogues exert their pharmacological effects through altering the complex hormonal milieu regulating lactation, particularly prolactin and oxytocin. This narrative review provides an appraisal of the existing evidence regarding the efficacy and safety of pharmaceutical treatments for lactation insufficiency to guide their use in clinical practice. The greatest body of evidence surrounds the use of domperidone, with studies demonstrating moderate short-term improvements in breast milk supply. Evidence regarding the efficacy and safety of metoclopramide is less robust, but given that it shares the same mechanism of action as domperidone it may represent a potential treatment alternative where domperidone is unsuitable. Data on remaining interventions such as oxytocin, prolactin and metformin is too limited to support their use in clinical practice. The review provides an overview of key evidence gaps and areas of future research, including the impacts of pharmaceutical galactagogues on breast milk composition and understanding factors contributing to individual treatment response to pharmaceutical galactagogues.

Supporting Mothers of Very Preterm Infants and Breast Milk Production: A Review of the Role of Galactogogues

Human milk, either mother’s own milk or donor human milk, is recommended as the primary source of nutrition for very preterm infants. Initiatives should be in place in neonatal units to provide support to the mother as she strives to initiate and maintain a supply of breast milk for her infant. The use of galactogogues are considered when these initiatives alone may not be successful in supporting mothers in this endeavor. Although there are non-pharmacologic compounds, this review will focus on the pharmacologic galactogogues currently available and the literature related to their use in mothers of very preterm infants.

Current concepts in migraine and their relevance to pregnancy

The prevalence of migraine in women of childbearing age is high, estimated at 24%. Migraine management during pregnancy and lactation can be challenging. Our understanding of the way in which medications affect the unborn fetus is still incomplete and the evidence is constantly changing with more recent emphasis on longitudinal studies and childhood development. The aim of this article is to describe the relationship between migraine and pregnancy and review the current evidence on treatment options in pregnancy and lactation.

Pharmacological treatment of migraine during pregnancy and breastfeeding

Migraine affects up to 25% of women of reproductive age. In the majority of these women, migraine improves progressively during pregnancy, but symptoms generally recur shortly after delivery. As suboptimally treated migraine in pregnancy could have negative consequences for both mother and fetus, the primary aim of clinicians should be to provide optimal treatment according to stage of pregnancy, while minimising possible risks related to drug therapy. Nonpharmacological approaches are always first-line treatment, and should also be used to complement any required drug treatment. Paracetamol is the preferred drug for acute treatment throughout pregnancy. If paracetamol is not sufficiently effective, sporadic use of sumatriptan can be considered. NSAIDs such as ibuprofen can also be used under certain circumstances, though their intake in the first and third trimesters is associated with specific risks and contraindications. Preventive treatment should only be considered in the most severe cases. In women contemplating pregnancy, counselling is essential to promote a safe and healthy pregnancy and postpartum period for the mother and child, and should involve a dialogue addressing maternal concerns and expectations about drug treatment. This Review summarizes current evidence of the safety of the most common antimigraine medications during pregnancy and breastfeeding, and provides treatment recommendations for use in clinical practice.

Safety of Drugs during Pregnancy and Breastfeeding in Cystic Fibrosis Patients

Health management of cystic fibrosis (CF) patients should be maximized during pregnancy and breastfeeding because of its significant impact on the maternal and newborn outcomes. Thus, numerous drugs will have to be continued during pregnancy and lactation. Most of the drugs representing CF treatment lines cross the placenta or are excreted into human milk. Research addressing the risks and benefits of drugs used in CF patients during pregnancy and lactation is often incomplete or challenged by limited methodology, which often leads to conflicting or inconclusive results. Yet, potential treatment benefits for CF pregnant patients most often outbalance potential risks for the unborn child.

Maternal medication, drug use, and breastfeeding

This article reviews the necessary skills required for clinicians to make informed decisions about the use of medications in breastfeeding women. Even without specific data on certain medications, this review of kinetic principles, mechanisms of medication entry into breast milk, and important infant factors can aid in clinical decision making. In addition, the article reviews common medical conditions (eg, depression, hypertension, infections) in breastfeeding women and their appropriate treatment.

[Anesthesia and analgesia in the lactation period. Criteria for drug selection]

There is no sound information concerning the safe and correct use of analgesics and anesthetics during the lactation period based on studies with a large sample size. Available information is limited to case studies and small sample observations. As a result, information given by the drug manufacturers about the use of drugs during the lactation period is often restrictive or contains contraindications for the lactation period. Although some drugs are not officially licensed for use during lactation they need to be administered in daily (off-label) use. This review gives an overview about the recent knowledge and clinical experience concerning the perioperative use of anesthetics and analgesics during breast feeding.

Breastfeeding and migraine drugs

PURPOSE

Breastfeeding women may suffer from migraine. While we have many drugs for its treatment and prophylaxis, the majority are poorly studied in breastfeeding women. We conducted a review of the most common anti-migraine drugs (AMDs) and we determined their lactation risk.

METHODS

For each AMD, we collected all retrievable data from Hale's Medications and Mother Milk (2012), from the LactMed database (2014) of the National Library of Medicine, and from a MedLine Search of relevant studies published in the last 10 years.

RESULTS

According to our review, AMDs safe during breastfeeding are as follows: low-dose acetylsalicylic acid (ASA), ibuprofen, sumatriptan, metoprolol, propranolol, verapamil, amitriptyline, escitalopram, paroxetine, sertraline, acetaminophen, caffeine, and metoclopramide. AMDs compatible with breastfeeding but warranting caution are as follows: diclofenac, ketoprofen, naproxen, most new triptans, topiramate, valproate, venlafaxine, and cyproheptadine. Finally, high-dose ASA, atenolol, nadolol, cinnarizine, flunarizine, ergotamine, methysergide, and pizotifen are contraindicated.

CONCLUSIONS

According to our review, the majority of the revised AMDs were assessed to be compatible with breastfeeding.

Safety of the breast-feeding infant after maternal anesthesia

There has been an increase in breast-feeding supported by the recommendations of the American Academy of Pediatrics and the World Health Organization. An anesthesiologist may be presented with a well-motivated breast-feeding mother who wishes to breast-feed her infant in the perioperative period. Administration of anesthesia entails acute administration of drugs with potential for sedation and respiratory effects on the nursing infant. The short-term use of these drugs minimizes the possibility of these effects. The aim should be to minimize the use of narcotics and benzodiazepines, use shorter acting agents, use regional anesthesia where possible and avoid agents with active metabolites. Frequent clinical assessments of the nursing infant are important. Available literature does suggest that although the currently available anesthetic and analgesic drugs are transferred in the breast milk, the amounts transferred are almost always clinically insignificant and pose little or no risk to the nursing infant.

The transfer of drugs and therapeutics into human breast milk: an update on selected topics

Many mothers are inappropriately advised to discontinue breastfeeding or avoid taking essential medications because of fears of adverse effects on their infants. This cautious approach may be unnecessary in many cases, because only a small proportion of medications are contraindicated in breastfeeding mothers or associated with adverse effects on their infants. Information to inform physicians about the extent of excretion for a particular drug into human milk is needed but may not be available. Previous statements on this topic from the American Academy of Pediatrics provided physicians with data concerning the known excretion of specific medications into breast milk. More current and comprehensive information is now available on the Internet, as well as an application for mobile devices, at LactMed (http://toxnet.nlm.nih.gov). Therefore, with the exception of radioactive compounds requiring temporary cessation of breastfeeding, the reader will be referred to LactMed to obtain the most current data on an individual medication. This report discusses several topics of interest surrounding lactation, such as the use of psychotropic therapies, drugs to treat substance abuse, narcotics, galactagogues, and herbal products, as well as immunization of breastfeeding women. A discussion regarding the global implications of maternal medications and lactation in the developing world is beyond the scope of this report. The World Health Organization offers several programs and resources that address the importance of breastfeeding (see http://www.who.int/topics/breastfeeding/en/).

Maternal medication, drug use, and breastfeeding

This article reviews the necessary skills required for clinicians to make informed decisions about the use of medications in women who are breastfeeding. Even without specific data on certain medications, this review of kinetic principles, mechanisms of medication entry into breast milk, and important infant factors can aid in clinical decision making. In addition, common medical conditions and suitable treatments of depression, hypertension, infections and so forth for women who are breastfeeding are also reviewed.

Chemotherapy, targeted agents, antiemetics and growth-factors in human milk: how should we counsel cancer patients about breastfeeding?

An increasing number of women are diagnosed with cancer during pregnancy and lactation. Women are usually advised to interrupt breastfeeding during systemic anticancer treatment for fear of serious adverse effects to the nursed infant. However, the issue is poorly addressed in the literature and very few studies have evaluated the safety of breastfeeding during or after cytotoxic drugs or target agents administration. In this review we will analyze the available evidence that addresses the issue of anticancer drugs, targeted agents, antiemetics and growth-factors excretion in human milk. This could serve as a unique resource that may aid physicians in the management of breastfeeding cancer patients interested in maintaining lactation during treatment.

A critical review of pharmaceutical galactagogues

Use of plant and drug products to enhance lactation is widespread, and numerous papers have been published in the medical literature claiming efficacy for various products. This paper will review and evaluate the published literature on the most widely used pharmaceuticals that are used as galactagogues. Breastfeeding physiology is reviewed with the aim of creating a framework for understanding galactagogue pharmacology. Published articles were selected and evaluated using the principles of evidence-based medicine, and were also evaluated using the principles of good lactation management. Only three studies on oxytocin and seven studies on dopamine antagonists were found to be useful. Oxytocin is probably not useful as a galactagogue, except possibly in rare circumstances of tetraplegic mothers. Dopamine antagonists appear not to enhance milk supply if mothers are given good lactation support and employ these practices. The safety of the dopamine antagonists has not been adequately evaluated, so their use should be avoided unless other measures have failed.

Study protocol: a double blind placebo controlled trial examining the effect of domperidone on the composition of breast milk [NCT00308334]

BACKGROUND

Domperidone, a drug that enhances upper gastric motility, is an anti-dopaminergic medication that also elevates prolactin levels. It has been shown to safely increase the milk supply of lactating women. To date, researchers have analyzed the effects of domperidone on lactating woman with respect to the quantity of their milk production, adverse effects, and drug levels in the breast milk. However, the effect of domperidone on the macronutrient composition of breast milk has not been studied and current guidelines for fortification of human milk for premature infants do not distinguish between those women using or those not using domperidone. The purpose of this study is to evaluate the effect of domperidone (given to lactating mothers of very preterm infants) on the macronutrient composition of breast milk.

METHODS/DESIGN

Mothers of infants delivered at less than 31 weeks gestation, who are at least 3 weeks postpartum, and experiencing lactational failure despite non-pharmacological interventions, will be randomized to receive domperidone (10 mg three times daily) or placebo for a 14-day period. Breast milk samples will be obtained the day prior to beginning treatment and on days 4, 7 and 14. The macronutrient (protein, fat, carbohydrate and energy) and macromineral content (calcium, phosphorus and sodium) will be analyzed and compared between the two groups. Additional outcome measures will include milk volumes, serum prolactin levels (measured on days 0, 4, and 10), daily infant weights and breastfeeding rates at 2 weeks post study completion and at discharge. Forty-four participants will be recruited into the study. Analysis will be carried out using the intention to treat approach.

DISCUSSION

If domperidone causes significant changes to the nutrient content of breast milk, an alteration in feeding practices for preterm infants may need to be made in order to optimize growth, nutrition and neurodevelopment outcomes.

Neonatal exposure to drugs in breast milk

There are many benefits of breast-feeding both for the infant and for the mother. Nursing mothers who are also taking medications or exposed to environmental hazards may be confronted with a difficult choice to discontinue nursing or maternal medication or risk potential harm to the infant. Frequently, these decisions are made without sufficient information or understanding of the factors influencing exposure. The current review explores two indices of exposure, together with their pharmacokinetic determinants. Both of the indices include the milk to serum (M/S) concentration ratio for a given drug and the volume of milk consumed. The first exposure term, EI(Dose), expresses neonatal dose as a percentage of maternal dose and is inversely related to the maternal systemic clearance. By contrast, the second exposure term, EI(Conc), expresses infant concentration as a percentage of maternal concentration and is inversely related to the infant systemic clearance. Issues related to intersubject variation in M/S (e.g., colostrum vs. mature milk, fore vs. hind milk) and infant clearance (e.g., ontogeny of elimination pathways, pharmacogenetics) and their role in modulating exposure are also discussed.

Prediction of milk/plasma concentration ratio of drugs

OBJECTIVE

The milk to plasma (m/p) concentration ratio of drugs is used to estimate the amount of drug offered to the suckling infant. Published literature was reviewed to identify drugs for which sufficient data exist for calculation of m/p ratio and to examine whether the existing empiric data agree with the published method of Atkinson for mathematical prediction of m/p ratios based on physiochemical characteristics.

METHODS

Using a comprehensive reference text, we identified studies reporting sufficient data to calculate m/p ratio based on the AUC for milk and plasma. Subsequently, we calculated the m/p ratio with Atkinson's formula based on pKa, lipophilicity, and protein binding. We then correlated the empiric versus predicted (calculated) m/p ratios.

RESULTS

Of 192 drugs of which at least some data on milk accumulation have been published, there were sufficient data to quantify m/p ratios for only 69 medications (78 studies). There was no significant correlation between the empiric m/p ratios and the predicted values using the Atkinson's model.

CONCLUSIONS

Reliable data on m/p concentration ratios exist for few medications. Presently, there is no appropriate model to predict milk concentrations of drugs in humans.

Transfer of drugs and other chemicals into human milk

The American Academy of Pediatrics places emphasis on increasing breastfeeding in the United States. A common reason for the cessation of breastfeeding is the use of medication by the nursing mother and advice by her physician to stop nursing. Such advice may not be warranted. This statement is intended to supply the pediatrician, obstetrician, and family physician with data, if known, concerning the excretion of drugs into human milk. Most drugs likely to be prescribed to the nursing mother should have no effect on milk supply or on infant well-being. This information is important not only to protect nursing infants from untoward effects of maternal medication but also to allow effective pharmacologic treatment of breastfeeding mothers. Nicotine, psychotropic drugs, and silicone implants are 3 important topics reviewed in this statement.

Gastrointestinal medications and breastfeeding

Medications used to treat gastrointestinal symptoms are increasingly being used as more have been gained nonprescription status. Most of the gastrointestinal medications, such as laxatives, antacids, and antidiarrheal agents, are used short term. Women who breastfeed should be aware of the risks of taking any medications, whether prescription or nonprescription. There is little information describing transfer into breast milk for many of these products. Cimetidine, atropine, cascara, cisapride, loperamide, magnesium sulfate, and senna are the only products identified by the AAP as compatible with breast feeding. Metoclopramide is listed by the AAP as a drug whose effect on nursing infants is unknown but may be of potential concern, although studies published to date have not reported any adverse effects. The safest laxatives and antidiarrheals are those that are not absorbed and should be considered first-line therapy for conditions of constipation or loose stools. Famotidine and nizatidine are excreted into breast milk to a lesser extent than cimetidine or ranitidine and may be the preferred histamine antagonists. Despite the limited data on the use of cisapride in nursing women, it is considered safe by the AAP and may be preferred over metoclopramide for first-line prescription treatment of heartburn. Although most of these agents appear safe in the nursing infant, caretakers should be aware of the potential adverse reactions that may occur in infants whose mothers require these products.

Metoclopramide: a novel and safe immunomodulating agent for restoring the depressed macrophage immune function after hemorrhage

BACKGROUND AND OBJECTIVE

Recent studies have shown that administration of the anterior pituitary hormone, prolactin, after hemorrhage restored the depressed immune responses that are observed under those conditions. Because metoclopramide (MCP) is known to increase prolactin secretion and ultimately plasma prolactin levels, we attempted to determine whether administration of metoclopramide after hemorrhage produces any beneficial effects on the depressed splenocyte and peritoneal macrophage immune function after severe hemorrhage.

DESIGN, MATERIALS AND METHODS

Mice were bled to and maintained at a mean arterial pressure of 35 mm Hg for 60 minutes, then adequately resuscitated and segregated into two groups. One group received saline vehicle; animals in the other group were treated with metoclopramide (100 microg/100 g body weight, subcutaneously) before resuscitation. Two hours after saline or MCP injection, the animals were killed and macrophage as well as splenocyte cultures established. Plasma corticosterone levels were also measured.

RESULTS

The proliferative capacity of the splenocytes as well as their ability to release interleukin (IL)-2 and IL-3 in response to mitogen was markedly improved in animals that had hemorrhaged and that were treated with MCP compared with saline-injected mice. Moreover, the depressed splenic and peritoneal macrophage IL-1 and IL-6 release after hemorrhage was restored with MCP treatment. Furthermore, treatment with MCP prevented the increase in blood corticosterone levels seen after severe hemorrhage.

CONCLUSION

These results support the concept that the immunosuppression after hemorrhage may be mediated by hormones from the hypothalamic-pituitary-adrenal axis. Furthermore, MCP may be a useful adjuvant in the treatment of the trauma-hemorrhagic shock-induced immunosuppression.

Drug therapy in the nursing mother

The benefits of breast-feeding on newborn and infant health and for the maternal-infant relationship are well established. It is a failing of health care providers that breast-feeding is too frequently interrupted because of unfounded concerns over the potential adverse effects of concurrent drug therapy in the nursing mother. An overwhelming minority of medications are contraindicated during lactation, while the vast majority are considered either safe to use or the risk versus benefit considerations clearly favor use with continuation of breast-feeding. For those drugs that may pose a potential concern to the newborn, there are practical suggestions and precautions that can be taken to minimize risk. These include such interventions as selection of alternative effective drug regimens with safer profiles in breast-feeding, timing of drug dosing to minimize accumulation in the breast milk, surveillance for newborn or infant symptomatology that may be a sign of toxicity, or even the determination of drug levels in the infant's circulation. With a commitment to the advantages of breast-feeding and the information contained both herein and elsewhere regarding the interaction of medical therapy, pharmacology, and lactation, it is hoped that the health care provider will be empowered both to encourage and counsel more effectively the parturient who wishes to breast-feed but is concerned about ongoing drug therapy during lactation.

Breast feeding and anaesthesia

Anaesthetists require a good knowledge of the excretion of drugs in breast milk and the potential hazards to suckling infants of drug ingestion via breast milk. A brief account of the physiology of lactation is given. The mechanisms of drug passage into breast milk are discussed followed by a review of the excretion in breast milk of drugs used in anaesthetic practice. Suggestions for the management of anaesthesia in breast feeding mothers are offered.

Drugs in human milk. Clinical pharmacokinetic considerations

Drugs ingested by a lactating mother would be expected to appear in human milk to some extent and be ingested by a breast-feeding infant. Drugs pass from maternal plasma into milk by passive diffusion and are distributed within the aqueous, protein and lipid phases of milk. Distribution into milk will be affected by physiochemical characteristics of the drug: acid-base characteristics, relative protein binding in plasma and milk, and lipid solubility, as well as milk composition. The milk-to-plasma concentration ratio is the most commonly quoted index of drug distribution into human milk. However, calculation of the daily infant dose of drug ingested in milk, and from this the dose in milk relative to the maternal dose on a weight-adjusted basis, is a more relevant indicator of infant exposure to a drug. This is particularly true for drugs with a high volume of distribution, for which only a small proportion of the mother's dose is contained within the plasma and available for distribution into milk. A better indication of infant exposure to a drug is the steady-state plasma drug concentration in a breast-feeding infant, the major determinants of which are the dose rate (via milk) and the oral availability and clearance in the infant. Although in neonates the rate of absorption may be different from adults, there is little evidence that its extent is significantly different. Clearance, however, is impaired in very young infants, particularly if premature. The decreased clearance would result in a proportional increase in steady-state plasma concentrations in the breast-feeding infant. Consideration of the dose ingested in milk and the approximate clearance in infants of different ages allows estimation of likely steady-state plasma concentrations in breast-feeding infants. From these considerations, recommendations regarding the safety of drugs during breast-feeding can be made. Drugs which are very toxic or have dose-independent toxicity should be considered separately. Recommendations regarding 'social' drugs such as nicotine, alcohol, caffeine and theobromine are particularly difficult, as doses are uncontrolled and vary variable.

Principles of drug biodisposition in the neonate. A critical evaluation of the pharmacokinetic-pharmacodynamic interface (Part I)

Rational pharmacotherapy is dependent upon an understanding of the clinical pharmacokinetic and pharmacodynamic properties of the drugs employed. Although the available data on drug biodisposition and action in the neonate have increased considerably in the last few years, pharmacokinetic-pharmacodynamic interactions for many drugs remain poorly understood. The ontogeny of drug absorption, distribution, metabolism, and elimination are addressed in this review. Drug absorption from any site depends upon both the physicochemical properties of the drug and a variety of patient factors. Absorption of orally administered drugs may be affected by changes in gastric acidity and emptying time as well as by bile salt pool size, bacterial colonisation, and extraintestinal disease states such as congestive heart failure. Factors affecting drug absorption following intramuscular, percutaneous, and rectal administration are also discussed. Drug distribution in the neonate is influenced by a variety of important and predictable age-dependent factors. The developmental aspects of protein binding and body water compartments are described. Additionally, hepatic drug metabolism assumes an important role in understanding the pharmacokinetic and pharmacodynamic properties of many compounds. Certain biotransformation pathways, including hydroxylation by the P450 mono-oxygenase system and glucuronidation, demonstrate only limited activity at birth, while other pathways, such as sulphate or glycine conjugation, appear very efficient at birth. Elimination of drugs excreted unchanged in the urine is dramatically reduced in the newborn, compared with older infants and children, due to immaturity of both glomerular filtration and tubular secretory processes. The glomerular filtration rate remains markedly reduced prior to 34 weeks gestational age, increasing as a function of post-conceptual age until adult values are achieved by approximately 2.5 to 5 months of age. Tubular secretory capacity is also limited at birth, approaching adult values by approximately 7 months of age. Published reports describing the pharmacokinetics and pharmacodynamics of commonly used drugs in the neonatal period, as well as differences in drug biodisposition among premature infants, full term neonates, and older infants and children, are reviewed. Our recommendations for neonatal drug therapy are based upon a critical interpretation of these data, an understanding of fetal development and maturational processes, and an understanding of how disease states may affect drug biodisposition in the neonate.

Metoclopramide--a review

Metoclopramide has wide applications in both clinical and experimental medicine. It is useful in the management of gastro-oesophageal reflux and gastric stasis. It is being used increasingly in the management of nausea and vomiting, and at high doses will significantly relieve the emesis that is induced by cytotoxic agents. Metoclopramide also has an important place in the investigation of the role of dopamine in physiological and pathological processes.

Metoclopramide and breast feeding: efficacy and anterior pituitary responses of the mother and the child

The purpose of this randomized, double-blind clinical study was to evaluate the efficacy of the antidopaminergic agent metoclopramide (MC) in the treatment of puerperal lactational insufficiency, and prolactin, TSH and free thyroxine responses of the mother and the child to this therapy. Therefore, 11 women received MC (10 mg 3 times daily orally) and 14 a placebo for 3 wk. MC increased the serum concentration of PRL from 57.5 + 45.5 U/l to 315.0 + 300.0 U/l (P less than 0.001), and the amount of daily milk yield in 8 women with established lactational deficiency rose from 285 + 75 ml to 530 + 162 ml (P less than 0.01) while the placebo was ineffective. Serum concentrations of TSH and free thyroxine did not change during either of the treatments. Serum concentrations of PRL, TSH and free thyroxine in the infants were similar in both groups and remained unchanged throughout the study. Our results suggest that MC is useful in the treatment of deficient puerperal lactation, and it does not stimulate the pituitary lactotropes or thyrotropes of the nursing infants.