Chapter 11 Antianxiety Agents Mosby items and derived

Antianxiety Agents An individual’s response to dental treatment can range from total relaxation to severe apprehension. Each dental patient should be assessed at each appointment for his or her stress level. Each patient should then be provided with the least stressful environment as possible while receiving dental treatment. Stress or anxiety due to dental treatment can be treated with both pharmacologic and nonpharmacologic methods. The treatment of choice is often dependent upon the patient and his or her stress level. Mosby items and derived items © 2007 by Mosby, Inc. , an affiliate of Elsevier Inc. 2

Antianxiety Agents Benzodiazepines The benzodiazepines are the most commonly used drugs to treat anxiety. Ø These drugs are well absorbed after oral administration. Ø Benzodiazepines are highly lipid-soluble and have a quick onset of action. Ø They easily cross the blood-brain barrier. Ø They are metabolized in the liver and excreted in the kidneys. Ø Mosby items and derived items © 2007 by Mosby, Inc. , an affiliate of Elsevier Inc. 3

Antianxiety Agents Benzodiazepines Ø Mechanism of Action • Benzodiazepines bind to benzodiazepine receptors in the CNS and act as agonists. • They enhance the action of the inhibitory neurotransmitter γ-aminobutyric acid (GABA). • This decreases excitation in the limbic system. Mosby items and derived items © 2007 by Mosby, Inc. , an affiliate of Elsevier Inc. 4

Antianxiety Agents Benzodiazepines Ø Pharmacologic Effects • Behavioral Effects Reduce anxiety and panic. Cause sedation. • Anticonvulsant Effects Prevent the spread of seizures in tissues surrounding the anatomic seizure focus. • Muscle Relaxation Skeletal muscle relaxation Mosby items and derived items © 2007 by Mosby, Inc. , an affiliate of Elsevier Inc. 5

Antianxiety Agents Benzodiazepines Ø Adverse Reactions • Adverse effects are simply an extension of the drugs’ pharmacologic effects. • Central Nervous System They are many and include: fatigue, drowsiness, muscle weakness, ataxia. • Anterograde Amnesia This effect when the drug is taken and can last up to several hours after. Mosby items and derived items © 2007 by Mosby, Inc. , an affiliate of Elsevier Inc. 6

Antianxiety Agents Benzodiazepines Ø Adverse Reactions • Respiratory Effects Can produce respiratory depression • Cardiovascular Effects Therapeutic doses have no effect on circulation. • Visual Effects Can produce diplopia, nystagmus, blurred vision • Dental Effects Xerostomia, increased salivation, swollen tongue, bitter or metallic taste Mosby items and derived items © 2007 by Mosby, Inc. , an affiliate of Elsevier Inc. 7

Antianxiety Agents Benzodiazepines Ø Abuse, Tolerance, and Overdose • Abuse, and physical dependence and tolerance have been • • • reported with benzodiazepine use. Psychological dependence can occur with large doses over an extended period of time. Benzodiazepines have a very wide therapeutic index. Excessively large doses must be used to achieve overdose because of their therapeutic index. Overdose is treated with supportive measures. In some instances, the benzodiazepine antagonist flumazenil is used to treat overdose. Mosby items and derived items © 2007 by Mosby, Inc. , an affiliate of Elsevier Inc. 8

Antianxiety Agents Benzodiazepines Ø Uses • The short-term treatment of anxiety, panic attacks, insomnia, and alcohol withdrawal. • Some benzodiazepines are used to treat seizure disorders. Mosby items and derived items © 2007 by Mosby, Inc. , an affiliate of Elsevier Inc. 9

Antianxiety Agents Mosby items and derived items © 2007 by Mosby, Inc. , an

Antianxiety Agents Barbiturates These drugs are the original sedative-hypnotics. Ø They have a very narrow therapeutic index. Ø They have been associated with a high rate of abuse and complete respiratory and cardiovascular depression. Ø They are lethal in an overdose. Ø Benzodiazepines have pretty much replaced barbiturates in treating anxiety, insomnia and panic because of their more acceptable safety profile. Ø Barbiturates are used to treat seizure disorders and to induce general anesthesia. Ø Mosby items and derived items © 2007 by Mosby, Inc. , an affiliate of Elsevier Inc. 11

Antianxiety Agents Barbiturates These drugs are well-absorbed both orally and rectally. Ø They are metabolized by the liver and excreted by the kidneys. Ø They produce their pharmacologic effect by enhancing GABA receptor binding. Ø Pharmacologic effects include central nervous system depression, analgesia, and anticonvulsant effects. Ø Mosby items and derived items © 2007 by Mosby, Inc. , an affiliate of Elsevier Inc. 12

Antianxiety Agents Barbiturates These drugs are relatively safe at usual therapeutic doses. CNS depression can be exaggerated in elderly patients and in those with liver or renal failure. Ø Higher doses can be lethal. Ø Chronic long-term use can lead to physical and psychologic dependence. Ø Barbiturates are contraindicated in persons with intermittent porphyria. Ø Barbiturates stimulate liver microsomal enzymes and interact with many different drugs. Ø Mosby items and derived items © 2007 by Mosby, Inc. , an affiliate of Elsevier Inc. 13

Antianxiety Agents Nonbenzodiazepine-Nonbarbiturate Sedative-Hypnotics Ø Ø Chloral hydrate is an expensive, oral drug that has a rapid onset and fairly short duration of action. Gastric irritation occurs and can be minimized by mixing it with food or milk. The liquid dose form has a disagreeable odor and taste and can be mixed with fruit juice. Psychologic and physical dependence can occur with long-term use of this drug. Mosby items and derived items © 2007 by Mosby, Inc. , an affiliate of Elsevier Inc. 14

Antianxiety Agents Nonbenzodiazepine Benzodiazepine Receptor Agonists These are the latest group of drugs used to treat insomnia. Ø They are not benzodiazepines but appear to bind to benzodiazepine receptors and decrease sleep latency. They appear to have little effect on the sleep cycle. Ø Because they have the potential to cause physical and psychologic dependence, these drugs are controlled substances. Ø These drugs have the ability to cause daytime sedation and impair driving the morning after nighttime administration. Ø Mosby items and derived items © 2007 by Mosby, Inc. , an affiliate of Elsevier Inc. 15

Antianxiety Agents Melatonin Receptor Agonists Ramelteon was recently approved by the FDA to treat insomnia that is characterized by difficulty falling asleep. Ø It is highly selective for melatonin receptors. Ø It is not a controlled substance. Ø Adverse effects do include somnolence and dizziness. Ø Mosby items and derived items © 2007 by Mosby, Inc. , an affiliate of Elsevier Inc. 15

Antianxiety Agents Centrally Acting Muscle Relaxants They exert their effects on the CNS to produce skeletal muscle relaxation. Ø They are used in treating back and muscle pain and in patients with muscle spasms due to a car accident. Ø Common side effects include GI upset, sedation, and dizziness. Ø Mosby items and derived items © 2007 by Mosby, Inc. , an affiliate of Elsevier Inc. 16