Hello, To withdraw from Pentazocine you should decrease dosage in tiny amounts, to avoid a withdrawal syndrome. Symptoms of pentazocine withdrawal can be chills, abdominal cramps, nausea, vomiting, fever, runny nose, restlessness, anxiety, itching, sweating, insomnia, tremors, and nightmares, a general feeling of illness that lasts two to six weeks, depending on the level of physical dependency. You should go through withdrawal from pentazocine under medically supervised condition because health professionals can ease your symptoms. The usual methods are to gradually reduce the amounts taken, substitute other drugs like methadone. I am very proud you have taken the big step to withdraw from this drug. Hope I have answered your query. Let me know if I can assist you further. Take care Regards, Dr Suzana Zharri, General & Family Physician