A recently-published study suggests that lowering the dose of Risperdal could lessen the severity of prolactin-related side effects, including gynecomastia.
The research, which appeared last December in BMC Psychiatry, involved 374 schizophrenia patients randomly assigned to one of three groups: :129 who were prescribed the initial optimal therapeutic dose of risperidone until one-year follow-up; 125 participants were prescribed the initial dose for 4 weeks; and 120 participants took the initial dose for 26 weeks. Participants in the latter two groups had their risperidone dose cut in half over 8 weeks following their initial regimen, which they maintained until the study concluded.
The authors of the study reported that larger doses of risperidone correlated with more severe prolactin-related symptoms. Patients who began receiving the drug at a younger age were more likely to experience symptoms than older patients. Female patients had 13.6% greater odds of developing prolactin-related problems.
“These findings indicate that the PRS severity was alleviated during the one year treatment period because of the dose reduction,” the authors concluded. “Attention should focus on the side effects of hyperprolactinemia during long-term treatment, especially with a high dose, females, younger age at onset, and more severe patients.”
Prolactin is a hormone that plays a role in female breast development and lactation. In addition to gynecomastia (excessive male breast growth), excessive levels of prolactin may be associated with:
Johnson & Johnson and Janssen Pharmaceuticals have been named defendants in more than 18,000 Risperdal lawsuits, including many that were filed on behalf of men and boys who allegedly developed gynecomastia due to its use. While Risperdal was not approved for any pediatric indications until 2006, plaintiffs charge that about 20% of prescriptions were written for children, allegedly due to the drug makers’ aggressive off-label marketing efforts. In 2006, the Risperdal label was updated to note that gynecomastia occurred in 2.3% of pediatric patients. Previously, gynecomastia was listed as a rare side effect that occurred in fewer than 1 in 1000 patients.
More than 5,000 Risperdal lawsuits have been centralized in a mass tort program underway in Pennsylvania’s Philadelphia Court of Pleas, where a series of gynecomastia cases have gone to trial over the past two years. Four of those trials have resulted in verdicts favoring plaintiffs, with damage awards ranging from $500,000 to $70 million.