What Are The Various Symptoms Of Opiate Dependency Individuals who are suffering from severe pain especially those who have cancer can be prescribed with Fentanyl by their doctor. As an opiate, this medicine has an addictive property which may cause patients to focus their lives on using the drug. As the body of clients becomes more tolerant to Fentanyl, they are likely to show drug-seeking behavior like stealing other person's prescription, visiting physicians frequently and making alterations to prescriptions just to acquire more of the medication.