Premedication involves both psychological preparation of the patient through discussion as well as administration of drugs to reduce anxiety, provide sedation and analgesia, and decrease anesthetic requirements. Common drugs given orally or intramuscularly 1-2 hours before induction include benzodiazepines like lorazepam and midazolam, opioids like morphine and meperidine, barbiturates like secobarbital and pentobarbital, and antacids. The goals of premedication are to reduce anxiety, provide sedation and analgesia, induce amnesia, decrease sympathetic responses, and prevent postoperative nausea and vomiting.

1. Premedication Management of anesthesia begins with preoperative psychological preparation of the patient and administration of a drug or drugs selected to elicit specific pharmacologic responses This initial psychological and pharmacologic component of anesthetic management is referred to as “Premedication”

5. Drugs and Doses used for Pharmacologic Premedication before Inaction of Anesthesia PO,IM PO 2-4 15-30 Lorazepam Temazepam IM PO,IM 2.5-5 5-10 Midazolam Diazepam Benzodiazepine IM IM 5-15 50-100 Morphine Meperidine Opioids PO,IM PO,IM 50-150 50-150 Secobarbital Pentobarbital Barbiturates Route of Administration Typical Adult Dose (mg ) Drug Classification

6. PO,IM,IV 10-20 metoclopramide Stimulates of gastric motility PO PO 15-30 ml 10-20ml Particulate Nonparticulate Antacids PO,IM,IV PO,IM PO 300 150 20-40 Cimetidine Ranitidine Famotidine H2 antagonists IM IM IM 0.3-0.6 0.3-0.6 0.2-0.3 Atropine Scopolamine Glycopyrrolate Anticholinergics PO IV 0.3-0.4 0.4-0.5 Clonidine Dexmedetomidine Alpha-2 agonists PO,IM IM 25-75 25-75 Diphenhydramine Promethazine Antihistamines

7. Anesthetic Drugs General anesthesia Supportive drugs Local analgesics

8. General anesthesia Inhalational agents IV agents Muscle Relaxants