Male breast growth caused by Invega is sparking more lawsuits.

Invega is an antipsychotic medication from Johnson & Johnson and is approved by the FDA to treat schizophrenia. Sometimes, doctors may prescribe Invega to treat bipolar disorder, autism, attention deficit hyperactivity disorder (ADHD), anxiety, insomnia and depression.

Invega is a derivative of Risperdal, which means it can have the same side effects.

Invega works by blocking dopamine receptors. Dopamine is a chemical produced in the body that links regions of the brain controlling emotions.

At the same time, Invega also blocks dopamine’s action on the pituitary gland. This can result in an increase in prolactin, the hormone that controls sex drive in males and enables lactation (breast milk production) in females.

When prolactin levels reach abnormally high levels, the condition is called hyperprolactinemia. The result is gynecomastia, which is male breast growth caused by Invega.

Most young men see breast enlargement due to not only fatty tissue, but also glandular tissue. Surgery may be necessary to reduce breast size when it is due to an increase of glandular tissue.

In a study of 1,885 children taking Risperdal, 43 boys exhibited gynecomastia. Since the FDA approved Risperdal and Invega for the treatment of children, many boys have experienced male breast growth caused by Invega or Risperdal.

Both drugs are apt to cause weight gain, which can make enlarged breasts appear even more pronounced.

After 10 weeks of Risperdal treatment, patients gained an average of 4.6 pounds, according to one study.

Patients on Risperdal had “a statistically significantly greater incidence of weight gain,” says the FDA.

Male Breast Growth Caused by Invega Affects All Ages

The American Association for Geriatric Psychiatry (AAGP) presented findings at their 2014 annual meeting that claimed men on Invega or Risperdal had a 69 percent higher risk of gynecomastia than nonusers.

“This is the first and largest epidemiologic study on this question using data from 1 million men in the United States,” said lead author Dr. Mahyar Etminan, a drug safety researcher in the Therapeutic Evaluation Unit at Provincial Health Services Authority of British Columbia, in an interview with Medscape Medical News.

Dr. Etminan and fellow researchers looked at information gathered from 1 million men between the ages of 45 and 80 who reported side effects from 2001 to 2011. Of that sample of men, 8,285 cases of gynecomastia were confirmed. The mean age was 65.5 years.

Their analyses showed that men on a competing medication, Seroquel, had a lower risk of developing man boobs than those taking Risperdal or Invega.

$2 Billion Settlement for Off-Label Marketing

In 2013, Johnson & Johnson subsidiary Janssen Pharmaceuticals agreed to a settlement with the U.S. Department of Justice. Among other allegations, the DOJ accused Janssen of engaging in “off-label” marketing of Risperdal. Off-label marketing is selling or promotion of a drug for reasons other than the conditions specifically approved by the FDA.

The $2 billion settlement resolved allegations that Janssen had marketed Risperdal for use in dementia-afflicted elderly patients and mentally ill adolescents.

If you or someone you know has experienced male breast growth caused by Invega or Risperdal, you could benefit from speaking with a lawyer regarding your options for receiving compensation.