The controversy over Risperdal gynecomastia has already led to millions of dollars in settlement money changing hands.

Scientists believe this Risperdal side effect may be directly related to the drug’s chemical mechanism of action.

Risperdal is a psychiatric medication also known generically as risperidone. It’s now FDA-approved as a treatment for schizophrenia and manic or mixed episodes associated with bipolar disorder.

Risperdal is also approved to treat troublesome behavioral symptoms in some children and teenagers who have autism. Doctors also have discretion to prescribe Risperdal for uses other than those approved by the FDA, despite Risperdal’s side effects.

Risperdal Gynecomastia

Risperdal is one of a group of medications known as atypical antipsychotics. These medications generally are effective against psychotic symptoms but also tend not to lead to neurologic movement disorders.

Risperdal is different from some other atypical antipsychotics in that it can cause prolactin levels to rise and stay high. Scientists think this effect may be the link between Risperdal and abnormal breast development in males, or gynecomastia.

Prolactin is a hormone produced by the pituitary gland. Normally, women have a higher level of prolactin than men do. Their prolactin levels typically increase during pregnancy and breast feeding, encouraging production of breast milk. Prolactin also occurs naturally in males, in whom it normally regulates sex drive.

Production of prolactin can be inhibited by the neurotransmitter dopamine, so anything that restrains the action of dopamine can cause an increase in prolactin. That’s where Risperdal comes in.

Part of Risperdal’s mechanism of action involves blocking dopamine from reaching its receptors. When that dopamine can’t do its job, prolactin levels rise – in males as well as in females.

These abnormal levels of prolactin are known as hyperprolactinemia. It can lead to growth of breast tissue and production of milk in males, the same as it normally does in pregnant females. Scientists believe this increase in prolactin may be what leads to Risperdal gynecomastia.

Researchers have found increased levels of prolactin in patients taking Risperdal, more so than with other atypical antipsychotics.

Elevated prolactin levels have been observed in as many as 90 percent of Risperdal patients, according to a study published in the Journal of Clinical Psychopharmacology in 1997.

Gynecomastia treatment may only require removing whatever is causing it. For Risperdal gynecomastia patients, that may simply mean switching to a different medication that doesn’t increase prolactin levels.

Some patients, however, have reported that Risperdal gynecomastia persisted even after discontinuing the medication. For these patients, gynecomastia treatment may require surgical breast removal.

J&J Settles Claims Over Risperdal Marketing

Gynecomastia coincidental with Risperdal treatment has been the subject of several products liability lawsuits against the makers of Risperdal.

Some of the plaintiffs take issue with the way Johnson & Johnson marketed Risperdal years ago, before it was FDA-approved for use in younger patients.

They say the company improperly promoted Risperdal for use in children before its safety and effectiveness in younger patients had been adequately evaluated.

Similar allegations were the subject of investigations run by the U.S. Department of Justice and the attorneys general of several states. J&J ended up paying millions of dollars to settle these allegations.