2014

2,495 words

Contents
Summary ............................................................................................. 2 Introduction ........................................................................................ 2 Opioids ................................................................................................ 2 Local Anaesthetics .............................................................................. 3 Side Effects.......................................................................................... 3 Pharmacodynamics ............................................................................. 4 Pharmacokinetics ................................................................................ 5 Legal Aspects ...................................................................................... 6 Conclusion .......................................................................................... 6 References .......................................................................................... 7

Table 1. Effects of CNS depression associated with increasing plasma concentrations of lidocaine................................................................. 4

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Summary
This report discusses the intended uses and advantages of two types of analgesic drugs, opioids and local anaesthetics. The severity of the side effects for each category of analgesia are assessed. Methadone is an opioid that is regularly used in veterinary medicine, the pharmacodynamics and pharmacokinetics of this opioid are compared against that of the common local anaesthetic, lidocaine. Opioids are classed as either schedule 2, 3 or 5 controlled drugs, due to the potential for abuse. Local anaesthetics are only classed as POM-VPS medicines and have a much lower risk of abuse.

Introduction
Analgesics are drugs that are administered to