Patients looking into the side effects of Invega paliperidone may eventually learn about gynecomastia, the growth of breast tissue in a male patient’s body.

Invega is also known by its generic name paliperidone. It was first approved by the FDA in 2006 as a treatment for schizophrenia. It has since been additionally approved to treat schizoaffective disorder.

Doctors may also prescribe Invega for other uses, known as “off-label uses,” on a case-by-case basis.

Invega also comes in a long-acting formulation known as paliperidone palmitate and marketed as Invega Sustenna.

Invega is one of the second generation of antipsychotic medications, a generation known as atypical antipsychotics. These medications generally work by blocking the action of certain types of receptors that respond to the neurotransmitters dopamine and serotonin.

Scientists believe that this particular combination of effects on both dopamine and serotonin help control both the positive (present, i.e. delusions) and negative (absent, i.e. lack of social interaction) symptoms of schizophrenia.

Side Effects of Invega Paliperidone

Like any other drug, Invega creates a risk of side effects. Some of the side effects of Invega paliperidone include headache, dizziness, tiredness, weakness, stomach pain, and either a dry mouth or an increase in saliva production.

Patients taking Invega also report weight gain, a side effect common to many atypical antipsychotics.

Invega and Gynecomastia

One of the less common but more insidious side effects of Invega paliperidone is the growth of breast tissue in male patients – a condition known clinically as gynecomastia.

Scientists believe the link between Invega and gynecomastia can be traced to the drug’s effect on neurotransmitters. When Invega suppresses the effect of dopamine, the pituitary gland may respond by increasing production of prolactin, a hormone that stimulates breast growth and milk production.

Prolactin levels naturally increase in women who are pregnant or nursing. But studies of patients who take atypical psychotics like Invega show that these patients also have increased levels of prolactin, regardless of their sex.

Increasing prolactin levels artificially can have the same effect on the male body that it does on a female body. The result for male patients – even adolescents and young boys – can be gynecomastia. It can be accompanied by milk production and discharge from the nipple, known as hyperprolactinemia.

As unusual as gynecomastia may seem, it’s generally not considered a significant threat to physical health. Most cases of gynecomastia tend to resolve once whatever is causing it has been discontinued.

Some cases aren’t so easily resolved, however. Sometimes male breast growth does not resolve on its own. Patients in that situation may need to undergo male breast reduction surgery to restore the normal shape of their body.

While the physical effects of gynecomastia may not be particularly problematic, the psychological side effects of Invega paliperidone can be significant.

These effects can be even more pronounced when the patient is an adolescent or young boy. Atypical antipsychotics like Invega have sometimes been prescribed off-label to patients in that age group as a treatment for various behavioral and emotional symptoms.

At the same time, gynecomastia may make these young male patients vulnerable to teasing and bullying by their peers. Studies have shown that young men who suffer from gynecomastia tend to score lower across the board on many different measures of mental health.