Other major side effects which are commonly reported by fentanyl users include diarrhea, nausea, constipation, dry mouth, somnolence, weakness, and sweating and, abdominal pain, headache, fatigue, anorexia and weight loss, dizziness, nervousness, hallucinations, anxiety, depression, flu-like symptoms, indigestion, shortness of breath, hypoventilation, apnea, and urinary retention.
Risks associated with Ativan withdrawal including grand mal seizures and death show that use of the drug should be discontinued very slowly with medical supervision and over a prolonged period of time.
Mixing fentanyl with heroin or other drugs such as cocaine greatly increases the potency of the drug and potential dangers.
Moderate alcohol consumption can cause depleted aerobic capacity and negative impact on endurance for up to 48 hours after the last drink has been consumed.