Merck Manual

Please confirm that you are a health care professional

honeypot link
Professional Version

Tranquilizers, Sedatives, and Analgesics


Linda Shell

, DVM, DACVIM-Neurology, Ross University School of Veterinary Medicine

Reviewed/Revised Mar 2015 | Modified Nov 2022
Topic Resources

Tranquilization reduces anxiety and induces a sense of tranquility without drowsiness. Drug-induced sedation has a more profound effect and produces drowsiness and hypnosis. Analgesia is the reduction of pain, which according to a drug’s effect, may be more pronounced in either the viscera or the musculoskeletal system ( see Pain Assessment and Management Pain Assessment and Management ). Many drugs cannot be categorized by only one pharmacologic effect, ie, as tranquilizers, sedatives, or analgesics. For example, many psychotropic drugs can either tranquilize or sedate according to the dose administered, and many sedatives are also analgesics. Also, drugs classified as tranquilizers, sedatives, and/or analgesics may have additional effects (eg, behavioral modification, antiemesis).

For drugs commonly used in various species for tranquilization, sedation, or analgesia, see Table: Dosage of Tranquilizers and Sedatives without Analgesic Effects Dosage of Tranquilizers and Sedatives without Analgesic Effects Dosage of Tranquilizers and Sedatives without Analgesic Effects and see Table: Dosage of Analgesics Dosage of Analgesics Dosage of Analgesics . Drugs that have some of these effects but are used mainly for other properties (eg, as antispasmodics, antiemetics, or preanesthetics) are not listed. Single-use doses are emphasized because many situations require only a brief duration of effect, but frequency of administration is also provided for drugs likely to be used for multiple-dose therapy. The dosages listed serve only as a general guideline and apply to the use of each drug alone, not to a combination for anesthesia or neuroleptanalgesia. No reference is made to schedule restrictions, extra-label use, or precautions in the use of these drugs; the product label and referenced texts should be consulted for information on the pharmacology and alternative applications of each drug.

quiz link

Test your knowledge

Take a Quiz!