Pregnancy and Reglan as Anti-Emetic for Nausea, Vomiting

Opinion on the Safety of using
Reglan (Metoclopramide) during Pregnancy,
while Breast-Feeding, or giving Reglan (Metoclopramide) to Infants

Use of Reglan is advocated by some to improve Breast-Feeding, to control Nausea during Pregnancy ("Morning Sickness), and to control Gerd in Babies and Infants. Presumably their physicians recommend that Reglan is Safe for these uses. DrugIntel takes exception to medical endorsement of the Safety of Reglan (Metoclopramide).

When any scientist, physician, pharmaceutical company, or the FDA says that a drug is "safe", what this really means is that no danger has been documented under the condition examined.

Although some sorts of damages caused by drugs are obvious - bone deformities, heart damage, or pigmentation of the teeth, to name a few examples - other types of damages may be difficult to detect or document because they are hard to measure.

Reglan (Metoclopramide) is a substituted benzamide drug of a well-characterized class of drugs called "neuroleptic antipyschotic" drugs. Originally intended as an antipsychotic drug, it was not able to compete with drugs like Thorazine (chlorpromazine) or Haldol (haloperidol) mostly because it crossed the blood-brain barrier poorly. In other words, it was difficult getting enough drug to make the trip from the stomach to the brain where it would limit schizophrenic symptoms. For this reason it was a good choice for a drug to treat emesis (nausea) or gastroesophageal reflux disorder, since for both of these the site of action is outside the brain.

It's important to realize that the blood-brain barrier (BBB) is not and all or none fence. The BBB will reduce the percentage of some chemicals (like metoclopramide) that cross from the bloodstream into the brain; but some will get in. If the dose is raised, more will get in. If the duration of use of a drug is increased, more will accumulate in the brain.

But in pregnancy, the fetus is outside the blood-brain barrier. The fetus is getting treated with a drug that suppresses schizophrenic symptoms. After birth, the infant's blood-brain barrier is not completely formed, and drugs normally kept out of the brain are able to get into the brain.

The neuroleptics including Reglan (Metoclopramide) can have a long term effect on the architecture of the brain. They cause permanent changes resulting in Tardive Dyskinesia. Exposing the brain of a fetus or an infant to a drug that has this ability to cause permanent changes is extremely foolish, from the point of view of a scientist.

Is it possible to detect and measure changes in Fetuses' and Infants' brains who were exposed to such drugs? In all likelihood, except for rare and huge changes, a small tendency to have thoughts characteristic of schizophrenia or depression will go undetected and unmeasured. There are no scales or measures - there is nothing like an echocardiogram or angiography of mental function. There is nothing in psychiatry like a color scale as is used to detect the darkening effect on teeth that use of tetracycline during pregnancy causes.

Clinically, even dramatic, blindingly obvious effects like loss of limbs (caused by the teratogen thalidomide) end up requiring large numbers of victims to become apparent, unless clinical trials are performed - and even these must be of a fairly large size (>1000 per group) and be more sophisticated than looking for skeletal malformations, arterio-venous malformations, or gross measures of motor development such as the age at which the infant lifts her head. Thus the assurances of some that "metoclopramide is the anti-emetic drug of choice during the first trimester" ring rather hollow.

Is Reglan (Metoclopramide) proven Safe for Pregnant Mothers or Breastfeeding Mothers to take? This would require clinical trials in Pregnant women to be performed. Have such clinical trials been performed? No. Why not? The true answer is that there is too great a risk of the pharmaceutical company being sued for damages in case the drug turns out to be unsafe, and the proof offered by a clinical trial is clear.

With full sympathy to the Pregnant Mother concerning nausea, which can be debilitating for some during every minute of Pregnancy, the risk of using drugs like Reglan (Metoclopramide) are not to be taken lightly.