Haloperidol secreted in breast milk

Balancing the Use of Medications While Maintaining Breastfeeding

Breast milk is the most beneficial nutrition a mother can give her infant. Fortunately, the dose of most drugs transferred into milk is small and does not lead to clinically significant effects on the infant. In almost all instances, the mother should be advised to continue breastfeeding. Certain medications are absolutely contraindicated, including anticancer agents, radioactive drugs, and those that inhibit milk production. However, most medications can be used safely. An improved understanding of the relationship between maternal and infant exposure to medications would provide a more enlightened understanding of the risk and benefit analysis for individual drugs.

Use of Psychotropic Medications in Breastfeeding Women

BACKGROUND

Breastfeeding women who are prescribed with psychotropic medications on a regular basis are often concerned, regarding the possible implications of such treatment on the breastfed infant. A mother's well-being has a direct influence on the well-being of the baby. However, the notorious reputation of psychotropic medications may lead to suboptimal prescribing by the physician and poor adherence by the mother.

METHODS

A PubMed search (from 1976 through February 2017) was conducted for commonly used psychotropic drug classes, as well as individual medications commonly prescribed in these classes, along with the MeSH terms "breastfeeding"/"lactation". In each case, we chose studies that describe the pharmacokinetics of passage into breast milk and/or adverse effects in breastfed infants.

RESULTS

No large-scale controlled studies regarding the safety of psychotropic medications in breastfeeding mothers were reported. Based on case reports and small studies, most psychotropic medications produce low milk levels and low plasma levels in the infant, while serious adverse effects in the breastfed infant are rarely reported. Safety data for some psychotropic medications are still unavailable.

CONCLUSION

According to the data available in the literature to date, most psychotropic medications are expected to produce low levels in breast milk with no clinical importance. Nevertheless, an individual risk-benefit assessment of a proposed treatment should always be performed, as inter-individual differences may have a substantial effect on the breastfeeding infant's response to the treatment. Further studies and additional objective data are needed to consolidate and improve our current knowledge of psychopharmacotherapy in breastfeeding women. Birth Defects Research 109:957-997, 2017. © 2017 Wiley Periodicals, Inc.

Psychotropic medication and breast-feeding

Adverse effects of psychotropic medication on breast-fed infants have not been studied in controlled and systematic research. Existing information comes from small case series and single case reports. These limited data confirm that psychotropics are excreted into breast milk and that the infant is exposed to them. In recent decades sufficient data have accumulated to allow psychiatrists to prescribe tricyclic antidepressants, selective serotonin reuptake inhibitors, conventional antipsychotics, carbamazepine and sodium valproate to breast-feeding mothers with safety. There are not sufficient data on atypical antipsychotics to allow women to breast-feed safely. Mothers on clozapine or lithium should not breast-feed. It is good practice to recommend that breast-feeding mothers requiring psychotropic medication be on a low dose of one single drug. Future research taking account of maternal mental health, psychopharmacological factors, infant physiological environment and individualised risk/benefit assessment will yield clearer responses to this complex issue.

Mood stabilizers and antipsychotics during breastfeeding: Focus on bipolar disorder

Breast milk is considered the best source of nutrients and provides much better protection than immune modified milk. However, the postpartum period is a phase of increased risk for all women to experience psychiatric symptoms and recurrences or new episodes of bipolar disorder (BD), especially in those who have discontinued treatment. This is a systematic review of the risks and benefits of mood stabilizers and antipsychotics during breastfeeding as they relate to the health and well-being of mothers and their infants. Evidence-based treatment advice for women with BD during lactation is also provided. This systematic review has been conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. We included studies examining the exposure and the effects of antipsychotics and mood stabilizers used to treat BD on infants during breastfeeding clearly reporting the estimated amount of drug or effects on infants. The final selection included 56 studies. The available data supports the use of lithium as a possible treatment option during breastfeeding. Carbamazepine and valproic acid are also considered relatively safe. Lamotrigine can be used but at the lowest doses and considered for individual cases. Among the antipsychotics, quetiapine and olanzapine should be considered as first-line treatment options. Risperidone may be compatible with breastfeeding under medical supervision. Clozapine and amisulpiride are currently contraindicated. Long-term outcome studies evaluating the infant׳s health and psychosocial and cognitive functioning are needed.

The quality of lactation studies including antipsychotics

THE AIM OF THE STUDY

The aim of this study is to determine the quality of lactation studies that investigated antipsychotics in breast milk according to the Food and Drug Administration (FDA) and International Lactation Consultant Association (ILCA) draft guidelines.

MATERIALS AND METHODS

We used the draft FDA and ILCA guidelines to review the quality of articles including antipsychotic use during breastfeeding. We used PubMed and Lactmed for the literature search. Furthermore, cross references were searched for additional studies.

RESULTS

Of the 51 studies, only one olanzapine and one quetiapine study calculated the milk to plasma ratio (M:P ratio), the Absolute Infant Dose (AID), and the Relative Infant Dose (RID) correctly. In the remaining studies, at least one of the three endpoints was not determined properly. No correct endpoints were calculated in studies containing chlorpromazine, chlorprothixene, clozapine, haloperidol, sulpiride, trifluoperazine, ziprasidone, zonisamide, and zuclopenthixol. This review investigated that there was a lack of information on the sampling methods of breast milk. Furthermore, the concentrations needed for the calculations of the three endpoints were mainly based on single measurements instead of at least five measurements during one dose interval. In many studies, the RID was not calculated correctly due to the fact that the RID was not normalized by the maternal weight or an average maternal weight of 70 kg was used as a standard.

CONCLUSION

Except for two studies, most studies about the safety of antipsychotic use during lactation did not meet the criteria of the draft FDA and ILCA guidelines. Further research is mandatory to assess the safety of using antipsychotics while breastfeeding.

Psychotropic medication during pregnancy and lactation

Despite the traditional notion that pregnancy is a time of joy and emotional well being, evidence suggests that it does not protect women against mental illness. Untreated mental illness carries wide-ranging repercussions for mother, child and family that often outweigh those associated with treatment. Clinical management is complex, involving competing risks to mother and offspring; the challenge lies in effectively treating mental illness, whilst minimising exposure of the child to harmful medication. The paucity of robust published evidence on which to base the principles of psychiatric care further compounds the issue. Pregnancy significantly affects plasma drug levels and immature foetal/neonatal physiology renders the child prone to damage from pharmacological agents, all of which cross the placenta/enter breast-milk to varying degrees. Risks include teratogenicity, obstetrical complications, perinatal syndromes, and long-term behavioural problems. Despite evidence that some psychotropic drugs may be safe during pregnancy, knowledge regarding the risks of antenatal exposure to medications remains far from complete. The pregnant or breastfeeding woman requires an individualised risk-benefit analysis with regard to the commencement or continuance of psychotropic medication. If treatment is deemed necessary, monotherapy at the lowest possible dose should be prescribed. More robust safety data is available for older psychotropic drugs, which should be employed in preference to newer agents with unestablished safety profiles. Pregnant/breastfeeding women should also be educated with regard to early detection of signs of drug toxicity in both themselves and their babies. Despite shared responsibility, the ultimate decision with regard to reasonable risk, and what constitutes it, rests with the informed patient. Close psychiatric monitoring and coordinated multidisciplinary care with the obstetrician and paediatrician combine with such informed patient choices to comprise the components of a holistic model of care, targeted at optimizing the complex management of women with psychiatric illness during pregnancy.

The role of estrogen therapy in postpartum psychiatric disorders: an update

OBJECTIVES

The aim of this review is to assess and summarize the existing literature data about the efficacy of estrogen replacement therapy (ERT) in preventing and treating postpartum psychiatric disorders.

METHODS

An extensive and unrestrictive computerized search (from 1970 to June 2005) on MEDLINE/PubMed, TOXNET, EMBASE, and Cochrane Databases was conducted with the following search terms: estradiol, estrogen-treatment, hormonal treatment, therapy, postpartum depression, postnatal depression, puerperal depression, postpartum blues, postpartum psychosis, lactation, and breastfeeding.

RESULTS

In assessing available literature information about the role of ERT in preventing and treating puerperal psychiatric diseases, all reviewed studies were found to suffer from severe methodological limitations.

CONCLUSION

Well-designed and strictly focused multicenter trials are warranted in order to firmly establish the effectiveness of ERT in puerperal psychiatric disorders.

The potential risks of commonly prescribed antipsychotics: during pregnancy and lactation

Chlorpromazine, haloperidol, fluphenazine, clozapine, risperidone, quetiapine, olanzapine, ziprasidone, and aripiprazole are antipsychotics commonly used in psychiatric medicine. Approximately one third of pregnant women with psychotic symptoms use antipsychotics at least once. This review will discuss the effects of antipsychotic use during pregnancy and lactation on the fetus and infant.Although adequate and well-controlled studies have not been done in any one of these antipsychotic drugs, animal studies have revealed evidence of teratogenic or embryo/fetotoxic effects in all of them. Toxicities include skeletal malformations, central nervous system (CNS) defects, cleft palate, cardiac abnormalities, decreased fetal growth, and fetal death. For example, in pregnant women, congenital malformations and perinatal death have been reported with chlorpromazine use. Both chlorpromazine and fluphenazine in monotherapy have been shown to cause extrapyramidal symptoms and respiratory distress in infants born to mothers treated with these medications. Haloperidol use during pregnancy has been linked to severe limb reduction defects.Effects of antipsychotic use in lactating mothers are mostly unknown. However, the use of chlorpromazine has been reported to result in drowsiness and lethargy in breastfed infants. Additionally, clozapine has been reported to cause sedation, decreased suckling, restlessness, irritability, seizures, and cardiovascular instability of infants were also reported with clozapine use in lactating mother. Use of antipsychotic drugs by pregnant and lactating mother may only be justified if the potential benefit outweighs the potential risk to the fetus.

Drug use and breastfeeding

Section 1 describes the benefits of breastfeeding to both mother and infant as well as the potential risks to the infant from maternal drug use. The extent of adverse drug-related events and the need for quality information on drug transfer is stated. Section 2 describes the physiology of lactation and the effects of drugs that stimulate or decrease milk production. Section 3 deals with transport mechanisms for drug passage into milk and factors that may modify the infant's exposure to drugs. The critical descriptors of 'absolute' and 'relative' infant dose are defined to give an objective measure of infant exposure to drugs in milk. Section 4 reviews new or commonly used drugs under the headings of analgesics and anti-inflammatory agents, neurological, endocrine, psychotropic and antihypertensive drugs. Section 5 concludes with an expert opinion of the drug industry and drug use in lactation, herbal preparations, the process of 'risk-benefit' analysis, minimising infant exposure, understanding drug-related adverse events and fostering good experimental design for drugs in lactation studies.

Antipsychotic medication during pregnancy and lactation in women with schizophrenia: evaluating the risk

OBJECTIVE

To review studies investigating the following: whether exposing developing infants to antipsychotic medication during pregnancy and lactation is associated with increased risks of teratogenic, neonatal, and long-term neurobehavioural sequelae; whether schizophrenia itself affects pregnancy outcome; and whether the course of schizophrenia symptoms is altered by pregnancy and lactation.

METHOD

We summarize the results from articles identified via a MedLine search for the period January 1, 1966, to December 1, 2001.

RESULTS

Women with schizophrenia are at increased risk for poor obstetrical outcomes, including preterm delivery, low birth weight, and neonates who are small for their gestational age. A lack of information in the literature makes it difficult to comment on the relative risk of exposing developing infants to atypical antipsychotics. However, typical antipsychotics appear to carry an increased risk of congenital malformations when the fetus is exposed to phenothiazines during weeks 4 to 10 of gestation. Lack of information also precludes an understanding of whether changes associated with pregnancy and lactation significantly alter the course of schizophrenia symptoms.

CONCLUSION

Research is needed so that physicians may more accurately inform women about the relative risks of using antipsychotic medications during pregnancy and lactation. Increased knowledge about the risks of medication exposure will allow clinicians to limit treatment to situations in which the risk of untreated maternal illness outweighs the risk of exposing a developing infant to medications.

Molecular descriptors that influence the amount of drugs transfer into human breast milk

Most drugs are excreted into breast milk to some extent and are bioavailable to the infant. The ability to predict the approximate amount of drug that might be present in milk from the drug structure would be very useful in the clinical setting. The aim of this research was to simplify and upgrade the previously developed model for prediction of the milk to plasma (M/P) concentration ratio, given only the molecular structure of the drug. The set of 123 drug compounds, with experimentally derived M/P values taken from the literature, was used to develop, test and validate a predictive model. Each compound was encoded with 71 calculated molecular structure descriptors, including constitutional descriptors, topological descriptors, molecular connectivity, geometrical descriptors, quantum chemical descriptors, physicochemical descriptors and liquid properties. Genetic algorithm was used to select a subset of the descriptors that best describe the drug transfer into breast milk and artificial neural network (ANN) to correlate selected descriptors with the M/P ratio and develop a QSAR. The averaged literature M/P values were used as the ANN's output and calculated molecular descriptors as the inputs. A nine-descriptor nonlinear computational neural network model has been developed for the estimation of M/P ratio values for a data set of 123 drugs. The model included the percent of oxygen, parachor, density, highest occupied molecular orbital energy (HOMO), topological indices (chiV2, chi2 and chi1) and shape indices (kappa3, kappa2), as the inputs had four hidden neurons and one output neuron. The QSPR that was developed indicates that molecular size (parachor, density) shape (topological shape indices, molecular connectivity indices) and electronic properties (HOMO) are the most important for drug transfer into breast milk. Unlike previously reported models, the QSPR model described here does not require experimentally derived parameters and could potentially provide a useful prediction of M/P ratio of new drugs only from a sketch of their structure and this approach might also be useful for drug information service. Regardless of the model or method used to estimate drug transfer into breast milk, these predictions should only be used to assist in the evaluation of risk, in conjunction with assessment of the infant's response.

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.

The effects of acute antipsychotic drug administration on the neurotensin system of the developing rat brain

The effects of antipsychotic drugs on the neurotensin (NT) system have been well characterized in adult male animals. There is considerable evidence that the NT system undergoes distinct age-related changes during development of the rat brain. This observation in conjunction with antipsychotic pharmacotherapy in children and breast feeding women led us to characterize the effects of antipsychotic drug administration in neonatal rats. The effects of a single subcutaneous injection of haloperidol (2.0 mg/kg) on the developing NT system were determined between postnatal days 10 and 21. Haloperidol significantly increased NT/neuromedin N (NT/NN) mRNA expression and NT concentrations in the caudate/putamen as early as postnatal day 10. Haloperidol did not increase NT/NN mRNA expression in the nucleus accumbens until postnatal day 15 and did not increase NT concentrations in this brain region until postnatal day 21. These results demonstrate that there is a critical time point in development before which the NT system does not respond to antipsychotic drug administration in the same manner as the mature rat.

Antipsychotics and breast-feeding: a review of the literature

Many women with mental illnesses would like to breast feed their infants. In light of the limited but rapidly growing data, it seems that in some cases the possible physiological and psychological benefits may outweigh putative risks. All antipsychotics are secreted into breast milk but the concentrations and effects vary. There is a subgroup of mothers with mental illnesses who want to breast feed their infants and who are receiving a single established antipsychotic drug (principally, haloperidol or chlorpromazine) at the lowest possible clinically effective dose. As a tentative conclusion, this group could experience benefits from being able to nurse which would outweigh the risk of exposing their babies to very small amounts of antipsychotic drugs. However, larger study groups with longer follow-up periods would be required to confirm this tentative conclusion. Those mothers who require 2 or more antipsychotic drugs simultaneously and those taking one drug, but at the upper end of the recommended dose range, should not be advised to breast feed. Safety considerations suggest that women taking atypical antipsychotics would be advised not to breast feed because of the limited experience with these agents. When mothers taking antipsychotic drugs do nurse, it is desirable to monitor drug concentrations in breast milk and in the infants themselves. Close monitoring of the infant is essential.

Psychotropic drugs in mothers' milk: a comprehensive review of assay methods, pharmacokinetics and of safety of breast-feeding

Many mentally ill women want to breast-feed their babies but, if they are taking psychotropic drugs, there is very little systematic data upon which to base decisions about whether or not it is safe to do so. We therefore attempt to provide a comprehensive and critical summary of existing case reports and of studies of breast-feeding in relation to commonly used psychotropic drugs. The literature review focuses on the following drugs: antidepressants: tricyclics and serotonin selective reuptake inhibitors (SSRIs); antipsychotic drugs: chlorpromazine, perphenazine, haloperidol and clozapine; mood stabilizers: lithium and carbamazepine; and benzodiazepines. The research literature consists mainly of single case reports and there have been very few attempts at controlled, longitudinal investigations. Findings are often difficult to compare because of differences in methods or because of lack of key information. Most data are available about the tricyclic antidepressants but even here we have found that the reports cover only a grand total of 66 mother-infant pairs. Dilemmas about whether or not to contraindicate breast-feeding arise most commonly in relation to postnatal depression. The findings to date suggest that provided that infants are healthy at the outset it is likely that the benefits of breast-feeding will outweigh potential hazards if their mothers are taking established tricyclic drugs at recommended dose levels. Much less is known about risks associated with SSRI antidepressants or about antipsychotic drugs such as phenothiazines and butyrophenones or mood stabilizers such as carbamazepine, all of which enter breast-milk. Safeguards are suggested for future single case studies, which, as they accumulate, will provide a platform for mounting controlled prospective studies properly to test for any acute toxic effects and for possible long-term adverse effects of such drugs on infants' development. Appendix 1 is a review of assay methods. Appendix 2 examines pharmacokinetic factors in newborn preterm and sick infants with special reference to contraindications to breast-feeding. Appendix 3 is a review of methods for assessing infant health and development.

A guide to the safety of CNS-active agents during breastfeeding

For most agents with CNS activity, there are limited data regarding their safety in breastfeeding. Any decision to institute treatment for a neurological or psychiatric disorder must weigh the benefits of maternal treatment against the potential harm to the breastfeeding mother of withholding medication which may improve her illness. For the neonate, one must balance the risk of medication exposure against the benefit of receiving breast milk. Most tricyclic antidepressants can be used in lactating women. Because of the limited data, selective serotonin (5-hydroxytryptamine; 5-HT) reuptake inhibitors should only be used with due consideration of the potential adverse effects. Breastfeeding is best avoided by women who require lithium therapy, because of both the immature excretory systems in the infant and relatively high doses received by the infant. There is little information about the safety of antipsychotic medications in breastfeeding. Concerns include toxicity and abnormal neurological development in the infant. These agents may be used with caution. Most agents which cause depression of the CNS, including opiates and sedatives, can be used in small doses and for short courses in breastfeeding mothers. Most anticonvulsants can be used in lactating women. Reference texts and consultation with experts are useful adjuncts to discussion of the risks and benefits of therapy with the patient. The scope of this review is limited to drugs with therapeutic uses, thus drugs of abuse are not discussed, nor are caffeine and alcohol (ethanol).

Excretion of psychoactive drugs into breast milk. Pharmacokinetic principles and recommendations

The postpartum period is a time of great physical and emotional changes. The incidence of psychiatric illness is higher in this period than at any other time in a women's life. Therefore, the question of whether women receiving psychotropic drugs should continue breast feeding is an important one. Drug excretion in breast milk depends mostly on passive diffusion of the unionised unbound drug. Passive diffusion is affected mainly by the drug disposition in lactating mothers, by the physicochemical properties of the molecule and by the protein and lipid contents of breast milk. Indeed, breast milk can be considered as a compartment with bidirectional transfer rather than a reservoir into which drug accumulates. Benzodiazepines are the most prescribed psychotropic drugs. Generally there does not seem to be any contraindication to breast feeding after a single dose, provided the dose administered is relatively low. If higher doses are to be used or long term administration is required, then breast feeding should probably be discontinued, particularly with drugs with a long elimination half-life. On the basis of the average concentration of phenobarbital (phenobarbitone) in milk, breast feeding is not recommended. For glutethimide, breast feeding would appear to be safe for the infant when a single dose is taken occasionally. Zopiclone may also be prescribed on a short term basis to breast feeding mothers. Due to limited available data or to the large amount transferred to milk, administration of phenothiazines and nonphenothiazine tricyclic, butyrophenone, and benzamide antipsychotics to breast feeding mothers cannot be recommended. Breast feeding is not always considered an absolute contraindication to lithium therapy, but the mother should watch for signs of toxicity in her baby. Whether clomipramine should be contraindicated during breast feeding depends on the concentration of active metabolites in breast milk, and this has not yet been determined. It is probably safe for mothers to breast feed while receiving amitriptyline, but before more conclusive recommendations are made more infants should be studied. The available data suggest that the amount of doxepin and its metabolite in breast milk is small. However, the metabolite of doxepin may accumulate in the infant with risk of sedation and respiratory depression: therefore, an alternative antidepressant should be selected for breast feeding mothers.(ABSTRACT TRUNCATED AT 400 WORDS)

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.

Breastfeeding and the use of psychotropic medication: a review

The advisability of continuing breastfeeding is an important issue for women with postpartum depression or psychosis. A review of the literature on psychotropic drugs in breast milk is presented. All of the major classes of psychotropic drugs (antidepressants, antipsychotics, antianxiety agents, lithium, hypnotics) have been shown to pass into breast milk following maternal ingestion. Generally, the doses to which children are exposed from breast milk, calculated from measured milk/plasma ratios, are small. Nevertheless most authors err on the side of caution and suggest that breastfeeding be avoided. There is inadequate research on the excretion of drugs into breast milk and the effects on the infant.

An overview of somatic treatment of psychosis during pregnancy and postpartum

Treatment and management of the psychotic pregnant patient is insufficiently covered by most standard texts and the current literature. To date, there are no controlled studies on the efficacy of different therapeutic modalities during pregnancy. Medications that have proved effective in the treatment of the various psychoses are not without added risk for the pregnant patient. However, there is no effective medical treatment without attendant risk. Although the psychotic pregnant patient presents a therapeutic dilemma, these patients can be effectively treated by a program that allows for flexibility and innovation within the framework of sound conservative medical practice. Professional territorial difficulties can be avoided by a unified effort.

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.

Haloperidol decanoate. A preliminary review of its pharmacodynamic and pharmacokinetic properties and therapeutic use in psychosis

Haloperidol decanoate is a depot preparation of haloperidol, a commonly used butyrophenone derivative with antipsychotic activity. Haloperidol decanoate has no intrinsic activity: its pharmacodynamic actions are those of haloperidol--primarily that of central antidopamine activity. The monthly administered depot formulation has several clinical and practical advantages over oral haloperidol: better compliance and more predictable absorption; more controlled plasma concentrations; fewer extrapyramidal side effects; less frequent reminders of condition; and reduced medical workload. In open and controlled studies, haloperidol decanoate has produced adequate maintenance or improvement of the condition of patients with psychoses (mainly schizophrenia) when an abrupt change from orally administered haloperidol or other antipsychotic drugs has been instituted. Limited comparative studies indicate that the depot and oral forms of haloperidol are equally effective, and that haloperidol decanoate is at least as effective as depot forms of fluphenazine, pipothiazine, flupenthixol and perphenazine in controlling the symptoms of psychosis. Extrapyramidal side effects and the need for concomitant anti-Parkinsonian drugs may be a problem, but may be less frequent than with oral haloperidol or other depot antipsychotics. Thus, haloperidol decanoate offers a useful alternative in the treatment of psychoses to orally administered haloperidol or to other depot antipsychotic drugs.

Zuclopenthixol levels in serum and breast milk

Breast milk and serum samples were obtained from six psychotic patients 3 days-10 months after delivery. Five of the women were given zuclopenthixol PO daily, and one was given zuclopenthixol decanoate IM every 2 weeks. Zuclopenthixol was estimated in breast milk and serum by high performance liquid chromatography. The zuclopenthixol levels in milk were found to be 29% of the serum levels on average. Based on the drug levels found in milk, the daily dose to a suckling infant was estimated to be 0.5-5 micrograms zuclopenthixol, corresponding to a dose of 0.01-0.1 mg to an adult. It is not likely that such a low dose would cause any effects or side effects in the infant unless infants are very different from adults concerning metabolism or sensitivity to the drug. The suckling infants included in this study were apparently not influenced by the intake of zuclopenthixol with the milk.

Neuroleptics under high risk conditions

A critical review of various high risk situations in which neuroleptics could be used and have been used in clinical practice is presented. These high risk situations include: women of child bearing age (pregnant women, lactating and/or nursing mothers), the two extremes of life (children and the elderly), patients with sexual dysfunction, patients with tardive dyskinesia, non-psychotic psychiatric patients, physically ill and suicidal patients. The extraordinary applications of these drugs, such as for rapid tranquilization and megadose regimens are examined. The author provides guidelines for the use of neuroleptics in these clinical situations.