During the procedure the patient is often given sedation intravenously, employing agents such as fentanyl or midazolam. Although meperidine (Demerol) may be used as an alternative to fentanyl, the concern of seizures has relegated this agent to second choice for sedation behind the combination of fentanyl and midazolam. The average person will receive a combination of these two drugs, usually between 25 and 100µg IV fentanyl and 1–4mg IV midazolam. Sedation practices vary between practitioners and nations; in some clinics in Norway, sedation is rarely administered.