A family physician who formerly practiced in Muscatine and was found guilty in a drugs-for-sex scheme has voluntarily surrendered his Iowa medical license and paid a $10,000 civil penalty.

David V. Gierlus, 60, settled with officials at the Iowa Board of Medicine on Friday. Gierlus was found to have distributed drugs, such as hydrocodone, in exchange for sex from at least 18 female patients.

In January, Gierlus was charged with 95 counts of unlawful distribution of controlled substances. Last summer, Gierlus was charged in U.S. District Court in Davenport with three counts of unlawful distribution of the drugs.

Gierlus pleaded guilty to one of the criminal drug charges and was sentenced to eight years in prison and ordered to pay a $400,000 fine.

At the federal court hearing in July, it was disclosed that at one time, a nurse saw Gierlus sexually assault a patient but did nothing about it, U.S. District Judge Stephanie Rose said. Other times, Gierlus drugged patients in order to have sex with them, the judge added.

Rose called Gierlus' behavior "troubling" at the hearing, citing court records where he did not dispute that he had sexual contact with 18 victims, including three patients he injected with drugs before he assaulted them. Two of those patients lost consciousness and one lost control while he molested them, Rose said.

The judge called Gierlus a "sexual predator," saying he preyed on "vulnerable" women who suffered from mental illness or were victims of sexual abuse as children. Many of them were Medicaid patients, including one he gave rent money to, in exchange for sex, Rose said.

A doctor of osteopathic medicine, Gierlus had a family practice for years at Trinity Muscatine Clinic, 1518 Mulberry Ave. He was licensed to practice in Iowa on July 15, 1987.

His license was set to expire March 1, 2013, but he had stopped seeing patients after the federal charges were filed, UnityPoint Health Trinity spokeswoman Erin Lounsberry said last summer.

Gierlus also served as a deputy medical examiner for Muscatine County, according to 2011 state records.