Chlorpromazine

What is chlorpromazine?

Chlorpromazine is a first generation or typical antipsychotic medication. It is currently only available as a generic medication in the United States. Chlorpromazine is available in tablets and solution for injection and is taken once daily. It is only available by prescription from your doctor.

What is chlorpromazine used to treat?

Chlorpromazine is used to treat bipolar disorder, psychotic disorders, schizophrenia, chronic hiccups, nausea and vomiting, acute porphyria (a genetic condition that interferes with hemoglobin production and oxygen transport by red blood cells), presurgical anxiety, and tetanus in adults. Chlorpromazine is also used to treat severe behavioral issues, nausea and vomiting, presurgical anxiety, and tetanus in infants over 6 months old, children, and adolescents.

How does chlorpromazine work?

Chlorpromazine works by blocking dopamine receptors and decreasing the release of certain hormones in the brain. Chlorpromazine is also thought to decrease neuron activity in certain parts of the brain, leading to changes in body temperature, wakefulness, muscle tone, and reduced vomiting. 

If I am taking chlorpromazine, can it harm my baby?

There are limited human studies that have evaluated the safety of chlorpromazine during pregnancy. Available studies suggest chlorpromazine should be safe for use in women during pregnancy, especially when used occasionally and in small, effective doses. There are dangers to both mother and baby associated with untreated mental illness and other medical conditions requiring antipsychotic use during pregnancy. Perinatal complications such as extrapyramidal and withdrawal symptoms are common in newborns exposed to chlorpromazine during the third trimester of pregnancy. Caution is advised when using this medication in pregnant women. It is important to weigh the risks versus the benefits of chlorpromazine therapy before using this medication during pregnancy.

Evidence from animal studies with chlorpromazine:

In animal studies, when chlorpromazine is given in doses several times higher than recommended maximum human doses, it has been associated with skeletal defects, cleft palate, low weight gain in the baby, and death of the baby. 

Evidence for the risks of chlorpromazine in human babies:

There are case reports of newborns exposed to medications such as chlorpromazine who have developed jaundice and either abnormal or overactive reflexes. 

Babies born to women who have taken antipsychotics in the third trimester have developed abnormal muscle movement (extrapyramidal symptoms) and withdrawal symptoms upon delivery. Extrapyramidal symptoms can last for several months. Some withdrawal symptoms may resolve on their own or may require hospitalization of the baby. The following is a list of some extrapyramidal and withdrawal symptoms that have been reported in babies exposed to antipsychotics.

• Difficulty feeding
• Agitation
• Stiff muscle tone
• Low muscle tone (“Floppy baby syndrome”)
• Respiratory distress
• Drowsiness
• Tremor

The Collaborative Perinatal Project looked at 142 children exposed to chlorpromazine during the first trimester of pregnancy as well as another 284 children exposed to chlorpromazine anytime during pregnancy. Exposure during the first trimester or anytime during pregnancy did not increase the risk of birth defects. There was no effect on survival of the baby, birth weight, or intelligence at 4 years of age. Seven year data from this project also found that children exposed to chlorpromazine in utero were an average 3 cm taller than children not exposed to this medication in utero. Another study in 36 infants exposed to chlorpromazine during the first trimester of pregnancy found no increase in the risk of birth defects. A French study reported an increased risk of birth defects in babies with first trimester chlorpromazine exposure – 4 out of 57 babies exposed to chlorpromazine developed birth defects including a small head, clubfoot, or deformities of the hands (but many of these babies were exposed to chlorpromazine and another antipsychotic). 

It is recommended that women avoid chlorpromazine near term due to the risk of maternal low blood pressure and adverse effects in the baby. Chlorpromazine doses of 500 mg or greater near term are associated with respiratory depression, drowsiness, and extrapyramidal symptoms. 

Bottom line: Chlorpromazine should not be used during pregnancy unless the benefits of treatment outweigh potential risks to the baby. There have been limited human studies that have looked at the safety of this medication during pregnancy. Animal studies have shown that chlorpromazine may be harmful to the developing baby. Taking antipsychotics such as chlorpromazine during the third trimester of pregnancy may increase the risk that your baby is born with various health problems.

If I am taking chlorpromazine and become pregnant, what should I do?

If you are taking chlorpromazine and become pregnant, you should contact your doctor immediately. Your doctor will determine if your medication is medically necessary, or if it should be discontinued until after the birth of your baby.

If I am taking chlorpromazine, can I safely breastfeed my baby?

The American Academy of Pediatrics suggests that chlorpromazine has unknown effects on infants and may be of concern; the World Health Organization recommends avoiding breastfeeding when taking chlorpromazine or monitoring infants for side effects. Case reports have described drowsiness and lack of energy in nursing babies exposed to chlorpromazine in breast milk. Studies suggest babies are exposed to 0.03% to 1.3% of a maternal chlorpromazine dose through breast milk (10% or less of a dose is considered safe for exposure during breastfeeding). The manufacturer recommends either discontinuing breastfeeding or discontinuing this medication to prevent adverse events; it is important to consider the benefit of this medication to the mother and potential risks to the infant before making a decision. Infants should be monitored for drowsiness and neurodevelopment if mothers continue to take chlorpromazine while breastfeeding. Though limited, long-term follow-up information suggests nursing infants exposed to chlorpromazine alone through breast milk do not suffer from negative neurodevelopmental effects; combination of chlorpromazine with another antipsychotic may increase the risk of neurodevelopmental issues. Chlorpromazine may cause excessive breast milk production. 

Bottom line: In breastfeeding moms who are taking chlorpromazine, either breastfeeding or the medication should be discontinued. The long-term effects of this medication on the breastfed baby are unknown. Case reports describe drowsiness in nursing babies exposed to chlorpromazine.

If I am taking chlorpromazine, will it be more difficult to get pregnant?

A laboratory study found that chlorpromazine can decrease sperm motility. One study in female rats found chlorpromazine was associated with changes in the ovaries and reproductive cycles. 

If I am taking chlorpromazine, what should I know?

Chlorpromazine should not be used during pregnancy unless the benefits
of treatment outweigh potential risks to the baby. There have been limited human studies that have looked at the safety of this medication during pregnancy. Taking antipsychotics such as chlorpromazine during the third trimester of pregnancy may increase the risk that your baby is born with various health problems.

In breastfeeding moms who are taking chlorpromazine, either breastfeeding or the medication should be discontinued. The long-term effects of this medication on the breastfed baby are unknown. Case reports describe drowsiness in nursing babies exposed to chlorpromazine.

If I am taking any medication, what should I know?

This report provides a summary of available information about the use of chlorpromazine during pregnancy and breastfeeding. Content is from the product label unless otherwise indicated.

You may find Pregistry's expert reports about mental health disorders and the individual medications used to treat mental health disorders here.   Additional information can also be found in the resources below. 

For more information about chlorpromazine during and after pregnancy, contact http://www.womenshealth.gov/ (800-994-9662 [TDD: 888-220-5446]) or check the following links:

U.S. Food and Drug Administration: Chlorpromazine Prescribing Information

National Institute of Public Health: Bipolar Disorder

National Institute of Public Health: Schizophrenia