Florida grandmother Tibina Louissant, 53, has been arrested following an investigation of the Aug. 21, 2022, death of 11-month-old Josiah Fenelus. Louissant, the grandmother of the infant, is accused of giving her grandson cyproheptadine, an antihistamine. According to People, the Broward Sheriff's Office Homicide Unit arrested the woman on Oct. 13. A warrant obtained by the outlet stated that Fenelus was under the care of his grandmother when officers were called to the Oakland Park home, where the baby was "unresponsive." CBS News reported that the young boy was rushed to Broward Health Medical Center from his Florida home and pronounced dead at the scene. A police investigation found a "lethal concentration of the powerful antihistamine cyproheptadine" in the infant's system. Baby bottles found in the grandmother's home were tested earlier this year. Toxicology tests returned positive for cyproheptadine, a drug that is prescribed to help people gain weight. A final autopsy in August found the cause of the infant's death was due to "cyproheptadine toxicity." The baby's parents left him with his paternal grandmother at the 100 block of NW 40th Court residence. The investigation found no prior problems relating to the infant's medical history, and Louissant was the only one to use the bottles. According to the U.S. Food and Drug Administration, the antihistamine is commonly used as an allergy treatment. In the U.S., cyproheptadine requires a physician's prescription. The FDA lists death as one of the symptoms of an overdose of antihistamines. In the United States, cyproheptadine is contraindicated in infants "because a paradoxical central nervous system stimulation and respiratory depression can occur," the National Library of Medicine referenced from the Prescribers Digital Reference in a 2021 study about the safety of cyproheptadine. The infant's death was ruled a homicide, and Louissant was issued an arrest warrant in August, charged with aggravated manslaughter of a child. On Oct.14, the woman was released on bond, which Broward County Court Records showed was set at $50,000. The penalty if the matriarch is found guilty is a minimum of 13 years in prison to a maximum life sentence.