The Effects of Neurologic and Psychiatric Drugs on the Fetus and Nursing Infant: A Handbook for Health Care Professionals

Consider that you are a psychiatrist assessing a new patient in her first trimester of pregnancy who is severely depressed and psychotic. She refuses ECT. You want/need to begin an antidepressant and antipsychotic if possible. Will this book help you to decide which medication you can choose without unreasonable risk to her fetus? The answer is maybe.

The authors clearly state in a brief seven-page introduction the areas their book does and does not cover.

After the short introduction, the book reviews the effects of individual psychotropic and neurological medications on the fetus and breast-fed infant. Each drug is discussed in one to three pages according to the same format: rating of teratogenic risk (from none to high); quality of data supporting the risk assessment (from none to good), review of human and animal data supporting the assessment (including type of congenital malformation, nonteratogenic fetal effects, and perinatal effects associated with the medication and risks to the infant related to nursing).

The authors emphasize several caveats about their assessment of the effects of these medications on the fetus and infant. They note that their assessments apply to usual doses rather than toxic doses of the medication, that the discussion applies to monotherapy rather than to multiple drugs combined, and that the baseline congenital malformation rate in the general population is 5%, which should be considered in evaluating risk of malformations. The reader also becomes readily aware that the teratogenic risk of the drugs discussed are frequently listed as “undetermined” and that the quantity and quality of the data available for each drug are usually rated by the authors as none, very limited, or limited.

Psychotropic medications familiar to psychiatrists as having potential teratogenic risks (diazepam, lithium, carbamazepine, valproic acid) are discussed cogently, with risks ranging from unlikely (fluoxetine) to minimal (diazepam) to moderate (carbamazepine, valproic acid) to high (alcohol) and fair to good ratings of the quality and quantity of data supporting these conclusions. However, possibly disconcerting to the clinician are the numerous psychiatric drugs listed (e.g., clozapine, nefazodone, bupropion, venlafaxine) as having an undetermined risk for congenital defects with very limited or no data. (Olanzapine and quetiapine are not among the medications discussed, probably because the book has a 1998 publication date.) Equally troubling is that the information provided on the effects of medications on breast-fed infants varies widely. Many drugs have some information on the amount of drug ingested by nursing infants (generally based on case reports) but little else. Data on long-term consequences of such ingestion is extremely limited. The authors note that most psychiatric medications are regarded by the American Academy of Pediatrics as a concern “because of potential to alter CNS functioning.” As the authors point out, there is little evidence supporting (or refuting) this concern.

So what will this book do for the psychiatrist described in the opening paragraph faced with treating a pregnant, psychotically depressed patient? It will give such a clinician an understanding of the known risks to the fetus of prescribing psychotropic agents, provide guidance to further resources through the references provided, and reassure regarding selection of a few of the medications that might be chosen. It will also frustrate by illustrating that the information available for most psychotropic medication is very limited and far exceeded by what is not known. Therefore, this book may help the clinician decide if medication should be prescribed to pregnant patients by clearly describing which choices are potentially dangerous and why and thus alert the clinician to the degree of risk for a planned course of treatment. After assessing the risks to the fetus, which this book may help to do, the clinician must turn to assessing the risks to the mother of pharmacological treatment versus careful observation without medication, must balance these risks to the mother and fetus, and then must convey these risks and benefits to the patient. There is no book yet that can decide the “correct” course of action for every patient, but this book can help in the process of arriving at a rational clinical decision given our current state of knowledge.