Ketamine: A Good Antidepressant, but Not During Pregnancy

Ketamine has not been shown to be safe during pregnancy.

Reviewed by Abigail Fagan

Key points

• Ketamine is a useful antidepressant that can be rapid and effective.
• Ketamine has not been shown to be safe during pregnancy.
• Clinics administering ketamine should give warnings about getting pregnant during treatment.

Ketamine has long been used as an anesthetic. More recently, it is being used for treatment-resistant depression at doses much lower than those used to produce anesthesia.

While ketamine is not yet approved by the FDA for this new use, many academic centers are studying and treating such depressed patients with it. Private practice centers in the community, usually run by anesthesiologists or psychiatrists, also administer ketamine.

Ketamine can decrease severe depression and suicidal thoughts that have not responded to other medications. It is rapid-acting: sometimes, just one treatment with intravenous ketamine may greatly decrease suicidal thoughts for up to a week. That decrease in the risk of suicide provides time for making a longer-term treatment plan, one that will likely include frequent administration of ketamine over weeks or months.

Medical supervision is necessary. A temporary feeling of dissociation, disconnection from a person’s self or environment, may often occur while the drug is being administered, and psychological support may be needed if this is frightening. (Unfortunately, this characteristic has made ketamine increasingly sought-after and used as a street drug of abuse.)

The Problem With Ketamine Use During Pregnancy

Many psychiatric medications have been shown to be safe during pregnancy and breast-feeding. Ketamine, however, is not one of them. In part, this is because there is not yet a study done that examines outcomes of pregnancy when ketamine was used. This means that it is unknown whether or not ketamine is safe in human pregnancies. But, disturbingly, studies in animals have shown that ketamine has deleterious effects on the brains of developing fetuses and on animals' behaviors after they are born.

Important Steps Before Ketamine Is Used in Women

It is estimated that a third of patients being treated with ketamine are women who are not menopausal. For those about to receive ketamine, the treating clinic should do the following. If any steps are eliminated, patients should ask for them to be done.

• Information about avoiding pregnancy should be given when a pre-menopausal woman is first seen.
• A pregnancy test should be administered before treatment is started.
• The use of effective contraception should be discussed.
• Pregnancy tests should be done intermittently during treatment (which may last many months)

Ketamine can be an excellent fast-acting treatment for severe depression. There is a time and a place for it — but not during pregnancy.