Seizure susceptibility and avoidance conditioning in adult rats treated prenatally with chlorpromazine

Use of Antipsychotics in the Management of Schizophrenia during Pregnancy

The rapid development of pharmacotherapy has resulted in a growing clinical importance for the treatment of the increasing number of women with schizophrenia during pregnancy. An evolving database on reproductive health safety factors for women with schizophrenia has begun to be of assistance in optimising clinical benefits for women with childbearing potential. Given the prevalence of antipsychotic use during pregnancy in women with schizophrenia, it is important for the clinician to have a prepared approach to the administration of these agents. In general, the use of psychotropic medication during pregnancy is indicated when risk to the fetus from exposure to this medication is outweighed by the risks of untreated psychiatric illness in the mother. The preponderance of evidence from registries to large health surveys indicate that treatment with antipsychotic medication confers either no or a small nonspecific risk for organ malformations. According to the relevant literature published on the safety of antipsychotic medication during pregnancy, the findings are encouraging; however, the currently available data are very limited. Until there are more controlled prospective data on the impact of drugs on fetal and later development, the clinician will continue to work in a state of potential uncertainty, weighing partially estimated risks against managing individual clinical problems. The aim for the clinician should be to provide the best information available regarding the scope of possible risks associated with the treatment of schizophrenia during pregnancy. On the basis of the available data, generalisation is impossible and recommendations should be made on a drug-by-drug basis. The risks and benefits must always be carefully weighed for each patient on an individual basis. Only a woman who is well enough to acknowledge her pregnancy and her mental illness can effectively weigh the relative and partially unknown risks of treatment with antipsychotic medication against the highly probable risks of illness exacerbation if untreated.

Use of psychoactive medication during pregnancy and possible effects on the fetus and newborn. Committee on Drugs. American Academy of Pediatrics

Psychoactive drugs are those psychotherapeutic drugs used to modify emotions and behavior in the treatment of psychiatric illnesses. This statement will limit its scope to drug selection guidelines for those psychoactive agents used during pregnancy for prevention or treatment of the following common psychiatric disorders: schizophrenia, major depression, bipolar disorder, panic disorder, and obsessive-compulsive disorder. The statement assumes that pharmacologic therapy is needed to manage the psychiatric disorder. This decision requires thoughtful psychiatric and obstetric advice.

Psychotropic drugs in pregnancy and lactation

OBJECTIVE

This article reviews the literature on the use of psychotropic drugs in pregnancy and lactation.

METHOD

Medline search yielded more than five hundred titles. Articles were reviewed and ninety-one were selected for reference.

RESULTS

Fetal physiology and teratogenicity are discussed and the effects of specific drugs on the fetus and newborn are presented. When possible, recommendations for use or non-use are presented.

CONCLUSIONS

Though no controlled studies have ever been done in pregnant women to truly prove their safety, it appears that most, but not all, current psychotropic drugs appear fairly safe for use in pregnancy.

Prenatal haloperidol exposure: effects on brain weights and caudate neurotransmitter levels in rats

Monoamines may exert a trophic effect on early brain development. To assess the role of dopamine in prenatal neurological development of the rat, haloperidol (HAL) was given in daily 2.5 or 5 mg/kg SC doses to dams over gestational days 6 to 20. This treatment regime did not enhance fetal mortality, but did produce reliable, if modest, stunting of the body and brain weight of offspring. The 5 mg/kg HAL dose consistently reduced offspring brain weight to roughly 90% of controls. This effect was probably permanent, in that it was seen throughout maturation and in adults as late as 140 days of postnatal age. Appropriate controls showed that this effect was not due to drug-induced reductions in food intake, to the presence of HAL in maternal milk, or to behavioral abnormalities in HAL-exposed dams. These effects had, at best, modest regional specificity, in that most brain regions were affected, independently of degree of dopaminergic innervation. Closer investigation of HAL effects on the striatum suggested that this permanent weight reduction was not accompanied by alterations in striatal concentrations of monoamines, monoamine metabolites, amino acids, choline, acetylcholine, DNA, protein, or water. It is concluded that prenatal HAL does stunt growth, but that this effect may not involve a direct drug influence restricted to the fetal dopamine system in the brain.

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.

Effect of prenatal phenytoin administration on postnatal development of the rat: a behavioral teratology study

Adult pregnant Wistar rats were treated with phenytoin (100 Mg/kg) orally from day 7 to 19 of pregnancy, and a control group was pair-fed during the whole treatment period. Within 24 hours after parturition , the offspring were culled to six to eight per litter and reared by fostering or cross-fostering. The physical and behavioral development of the offspring was observe up to 90 days of age. There was a reduced survival of the offspring and a reduction in body weight which persisted to the end of the experiment, though both of these effects could be reduced by cross-fostering. Certain neurological defects were also seen in the prenatal phenytoin group. For example, there was a delay of up to 15 days in the development of the dynamic righting reflex, a decrease in ability of offspring to stay on a rotating rod, and a decrease in ability to walk along elevated parallel rods. There seemed also to be some loss of cliff avoidance. However, there was no change in the development of crawling and walking activities at 9-21 days of age, and no important changes were observed in a head dipping test or in a conditioned avoidance test at 26-34 days. There was a significant decrease in brain weight of the treated group at age 3 days which remained significantly lower than the controls even at 90 days, but no change in the brain/body weight ratio. There was no difference in cerebellar DNA content.

Experimental methods in behavioral teratology

The possibility that the exposure of the embryo to certain chemical substances can lead to behavioral disturbances is known from human epidemiological studies, e.g., in chronic poisoning with mercury and ethanol. Therefore, efforts are made to develop toxicological techniques with which new behavioral teratogens can be recognized. The review describes the most important experimental methods which are presently explored, and which are based on a rich body of knowledge accumulated by experimental psychologists. Most of the tests were developed with small animals, mostly with rats. They range from a rather straightforward determination of various reflexes to complex behavioral situations involving mechanical devices, operant conditioning techniques and procedures evaluating social behavior. In applying these methods in routine toxicology, it is important to remember, that many behavioral effects determined in newborn and adult animals are subtle. Moreover, they are influenced by a large variety of environmental factors affecting the health and the behavior of the mothers and of the offspring in the early and later phases of development. Therefore, the experiments must be conducted under highly standardized conditions and must be controlled rigorously. It is concluded that the best experimental strategy for the evaluation of potential behavioral teratogens is not yet established. Therefore, it would be premature to decide on a fixed protocol to be included in routine animal safety experiments for drugs and other chemical substances.

Enduring behavioural and biochemical effects in the adult rat after prolonged postnatal administration of haloperidol

Rats were administered 0.5 mg/kg SC of haloperidol (H) or saline (S) daily from day 1 after birth until 20 days of age. At 60 days of age (40 days after the postnatal treatment with H or S was interrupted) the stereotyped behaviour and the effects on locomotor activity elicited by apomorphine in S- and H-pretreated rats were investigated. The intensity of apomorphine (0.5--1 mg/kg, SC)-induced stereotyped behaviour was significantly greater in the H-pretreated group than in S-pretreated animals and this was accompanied by a much more marked reduction of locomotor activity in H-pretreated than in S-pretreated rats. Finally, at 80 days of age (60 days after the postnatal treatment with H or S was interrupted) rats were subjected to a Differential Reinforcement of Low Rates schedule (DRL 15-s). The results indicate that the acquisition of the DRL task performance criterion (Rs/Rf less than or equal to 2.5) was significantly more rapid on S-pretreated rats than in H-pretreated ones. In parallel biochemical experiments, acute H produced smaller increases in dopamine turnover in chronic H-treated rats compared with S-treated controls. These data indicate that H treatment in neonatal rats induces behavioural and biochemical changes which can be observed up to 60 days after H withdrawal.

Behavioral, biochemical and histological effects of prenatal administration of progesterone in the rat

Pregnant Wistar rats were injected with progesterone (1.5 mg/kg) between Days 8 and 21 of gestation and the behavioral, biochemical and histological effects of this treatment were observed in the offspring. The progesterone offspring weighed less than the control animals during this weaning and were retarded on one measure of exploratory activity in the open field. None of the other 29 tests used showed any significant difference apart from a 9% increase in the amount of brain DNA in the progesterone animals. It was concluded that these differences were fortuitous and that progesterone has no consistent or significant effects on brain development in rodents following prenatal administration.

Behavioral teratogenesis: a critical evaluation

A critical review of some relevant literature concerning the effects of prenatal administration of drugs and several other substances on postnatal behavior. Significant variables and problems in the adequate design of experiments to assess these effects are discussed. Although the evidence concerning prenatal drug effects on behavior is equivocal, sufficient data exist to indicate that this will continue to be a viable and important area of research in the future. Present results demonstrate the complexity of drug interactions with other variables.

Effects of testing age and fostering experience on seizure susceptibility of rats treated prenatally with chlorpromazine

Offspring of rats treated with 2 mg/kg body weight chlorpromazine (CPZ) on Days 5-8 of gestation had lower seizure thresholds than offspring of saline-treated controls at 30, 60, 90, and 120 days of age. The CPZ-treated offspring were also heavier than controls prior to weaning. Further analysis using cross-fostered litters indicated that at least part of the drug effect on seizure thresholds took place before birth, although a postnatal component was also demonstrated. A striking effect of the fostering experience itself on the seizure threshold prevented conclusions about the relative importance of prenatal and postnatal influences.

Modification of the behavioral response to drugs in rats exposed prenatally to chlorpromazine

Female rats exposed prenatally to low levels of chlorpromazine were less susceptible as adults to the rate-reducing effects of chlorpromazine and pentobarbital on fixed-interval performance of a food-reinforced operant. Males were not significantly affected by prenatal treatment.

Changes in developing behavior following prenatal administration of imipramine

Female rats were given oral doses of Imipramine (5mg/kg) from 14-21 days prior to mating to conception or Day 19 or gestation and the physical maturation and behavioral development of their offspring was compared with that of controls. There were significant differences between the weights of the Imipramine and control animals at 21 days and the appearance of some reflexes was delayed. Behavior in an open field was observed when the rats were 9, 13, 17 and 21 days of age and it was found that exploratory responses were less frequent in the drug exposed offspring. In contrast there were no obvious physical anomalies and the adult behavior of the Imipramine animals on a spontaneous alternation task and a swimming maze did not differ from that of controls.

The interaction of post-weaning housing conditions and prenatal drug effects on behaviour

Offspring of rats given oral doses of imipramine (5 mg/kg) from 14-2f gestation were reared, after weaning, in deprived or enriched environments. When tested in both a Henderson-type maze and a swimming maze no behavioural effects due to prenatal drug exposure were observed when the Ss were reared in a deprived environment. When the Ss were reared in an enriched environment the maze performance of those animals which had been exposed to imipramine or vitamin-A was significantly inferior to that of the control animals. The implications of these findings are discussed with respect to environmental interaction with prenatal drug effects on behavior.