A substance with sedative effect comprises a therapeutically effective amount of a gamma-pyrone such as comenic acid, meconic acid, chelidonic acid, and alike in a pharmaceutically acceptable carrier. When administered at a daily dosage of between 5 and 200 mg of active ingredient per kilogram of a body weight of a patient, the substance can be used to treat various neurotic disorders such as insomnia, anxiety, neurosis, depression as well as withdrawal symptoms for drug addiction patients, especially for patients addicted to opioid-based drugs. The substance can be delivered in a number of ways of systemic administration of a pharmaceutical agent including oral, parenteral, transdermal, and transmucosal administration. For drug addicted patients, the preferred method of administration involves a subcutaneous implant providing a continuous release of an active ingredient at an effective daily rate over the entire treatment period ranging from 5 to 30 days, and preferably from 13 to 20 days.
