Week Six: Sedatives & Hypnotic Agents

Question 1

Define anxiolysis?

Answer 1

Patient responds normally to verbal commands, some cognitive and coordination impairment, but able to breathe on own.

Question 2

Define conscious sedation?

Answer 2

Depression of consciousness during which patients respond purposefully to verbal commands either alone or with tactile stimulation, able to breathe on their own

Question 3

Sedation can be?

Answer 3

Prescribed the night before treatment or preoperatively to lower anxiety

Question 4

What is the role of the OHT in sedation?

Answer 4

• Identification of patients who may benefit from sedation and
discussing with dentist
• Providing instructions and arranging support for patients who have
sedation
• Be aware that a dentist or specialist must be endorsed by the DPBA
to practice conscience sedation- (this excludes nitrous oxide)
• In relation to relative analgesia- Note that according to the DPBA.
Can an OHT deliver nitrous oxide?
“No. They do not have the prescribing authority required under state and
territory drugs and poisons legislation to do so even if they may have been
trained to do so.”

Question 5

How do you manage a sedated/anxiolysed patient?

Answer 5

• Semi reclined position
• Patient should not be lying flat or head down
• Should be able to place patient in horizontal position rapidly if CPR required
• Rubber dam for airway protection
• Patients vital signs should be monitored by the appropriately trained staff during the procedure
and for at least 1 hour after the procedure

Question 6

What are sedative/hypnotic drugs?

Answer 6

• CNS depressants
• Calming, anxiolytic, sedative and hypnotic effects
• Effects are dose related
• Patient in semi reclined position is recommended

Question 7

Name the sedative and hypnotic drugs used in dentistry.

Answer 7

• Benzodiazepines
• Anti-histamines
• Halothenes

Question 8

What are types of benzodiazepines?

Answer 8

• Diazepam (Valium): Sedative, long acting, metabolised by cytochrome P450 enzyme system (Interacts the drugs such as Ketoconazole - Omeprazole)
• Temazepam: Short acting

Question 9

What are contraindications of benzodiazepines?

Answer 9

• Allergy
• Psychoses
• Acute angle glaucoma

Question 10

What are precautions of benzodiazepines?

Answer 10

• Additive effects when taken with other CNS depressants

Question 11

What are adverse effects of benzodiazepines?

Answer 11

• Dependence
• Delirium and memory impairment
• Can impair performance and motor skills
• Cause dry mouth, blurred vision and drowsiness

Question 12

Why are antihistamines useful in dentistry?

Answer 12

• Used primarily due to its sedative action which is less effective then benzos.
• Sedative effects are increased by concomitant administration of opioids

Question 13

How do antihistamines work?

Answer 13

By blocking histamine receptors.

First generation H1 antagonists are sedating types

Question 14

What are adverse effects of antihistamines?

Answer 14

• Drowsiness
• Potentiate other CNS depressants
• Sedating types may cause drying of mucous membranes
• Constipation
• Urinary retention

Question 15

What types of antihistamines do we use in dentistry?

Answer 15

Phenothiazines:
- Trimeprazine & Promethazine
These are used un sedation of children

Ethanolamines

• Doxylamine
• Sometimes used to reduce post-procedural nausea and vomiting

Question 16

Briefly, what is nitrous oxide?

Answer 16

A colourless non irritating gas with mild odour and taste - available in steel cylinders

Combined use of NO and O

Useful for TX of apprehensive but coop patients to tolerate treatment and may benefit some patients with the reduction of the gag reflex.

Question 17

What concentrations of NO are used?

Answer 17

Sub anaesthetic concentrations 2-50%

Question 18

What is the onset of action of NO?

Answer 18

20 seconds, peak effect is achieved within 3-5 minutes

Question 19

When administering NO what should be checked?

Answer 19

Confirm no airway compromise prior to treatment

• At the conclusion of administration of nitrous oxide for
10 or more minutes, administer 100% oxygen for 3 to 5 minutes to prevent an abrupt decrease in oxygen
saturation of arterial blood (termed ‘diffusion
hypoxaemia’). Recovery is quick as nitrous oxide is
rapidly removed from the body when 100% oxygen is administered.

Question 20

What are adverse effects of NO?

Answer 20

• Development of hypoxia

- Producing loss of consciousness and impaired cough and gag reflexes

Question 21

When is NO contraindicated?

Answer 21

• Impaired level of consciousness
• Severe chronic obstructive pulmonary disease
• Undrained pneumothorax and large lung cysts and in patients who have had recent middle ear surgery.

Other adverse effects can rarely occur, including hypotension, respiratory effects and nausea and vomiting.

Question 22

What is meththoxyflurane?

Answer 22

Sold under the brand name Penthrox among others, is an inhaled medication primarily used to reduce pain following trauma. It may also be used for short episodes of pain as a result of medical procedures. Onset of pain relief is rapid and of a short duration.

Question 23

What are precautions of using meththoxyflurane?

Answer 23

• Dose related renal impairment
• Liver disease
• IV adrenaline
• Diabetics
• Elderly and children