Introduction to Oral Sedatives: Benzodiazepines

by Alice Dong, BSc, DDS, MSc Candidate (Dental Anesthesia)

Dental anxiety is a common phenomenon among Canadians. All clinically active dentists have anxious patients in their rosters. The simplest choices available to you for anxiolysis are nitrous oxide and oxygen or oral benzodiazepines. If your office does not offer nitrous oxide sedation or if nitrous oxide alone is inadequate for patient management, it might be worth considering oral sedation. This article will serve as an introduction to oral sedation. This route of drug administration is available in all dental settings. Before practicing any sedation modality, practitioners must check with their provincial or territorial licensing body and review the sedation guidelines or Standard, to ensure they have the appropriate training and authorizations.

The oral route is one of the most common methods of drug administration due to its numerous advantages. It is an easy and low-cost method of drug administration, without the need for advanced equipment, and it is widely accepted by patients.1,2 However, the prolonged time of onset and the inability to titrate medications delivered orally may be a source of frustration for practitioners.1,2 As well, the success of conscious sedation techniques is largely determined by patient expectations. Nonetheless, oral benzodiazepines provide safe and effective anxiety relief.

Benzodiazepines are one of the major classes of anxiolytic medications.2 They are GABAA receptor agonists. Their binding to the α and γ subunits on the GABAA receptor allows an influx of chloride ion into neurons, leading to hyperpolarization and neural inhibition.1–4 The resulting effects include anterograde amnesia, anxiolysis, anesthesia, hypnosis, sedation, muscle relaxation and anticonvulsant activity.1,5 Benzodiazepines have a wide therapeutic range which confers them a wide margin of safety.1,2 Patients receiving this class of drug must be cautioned against driving motor vehicle or operating heavy machinery while these drugs are active in their systems.1 They must also avoid the simultaneous usage of additional CNS depressants, including opioids and alcohol, as enhanced effects of respiratory depression and/or sedation may develop.1,6 Triazolam, lorazepam and midazolam are three commonly prescribed benzodiazepines for the treatment of dental anxiety.

Triazolam (Halcion™)

Triazolam is a popular and effective sedative for managing dental anxiety. The half-life of triazolam is 1.5-5.5 hours, reaching peak plasma level at 1.3 hours following oral administration.1 It has no active metabolite and will result in minimal residual drowsiness following metabolism.1,2 It is metabolized by the liver1,2 and excreted in the urine.1

Availability:

  • Halcion™ is available in 0.125 mg and 0.25 mg tablets.

Dosage:

  • General adult oral minimal sedation dose is 0.125-0.25 mg.1,2
  • For most patients, 0.25 mg taken one hour prior to bedtime or at the dental appointment will provide adequate anxiety reduction.1
  • For pateints over 65 years old, 0.125-0.25 mg is recommended.1
  • Royal College of Dental Surgeons of Ontario (RCDSO) Standard of Practice:7
  • Minimal sedation: 0.125-0.25 mg
  • Moderate sedation: 0.375-0.5 mg

Drug Interactions:

  • When co-administered with other CNS depressants, including alcohol, opioids, or barbiturates, additive CNS depression may occur.1

Adverse Reactions:

  • The most common side effects include drowsiness (14.0%), headache (9.7%), dizziness (7.8%), and nervousness (5.2%).1

Contraindications:

  • Triazolam is contraindicated in pregnant patients.1

Lorazepam (Ativan™)

Lorazepam is another effective antianxiety and hypnotic medication. The half-life of lorazepam is 12 hours, reaching peak plasma level in 2 hours following oral administration.1 It is metabolized by the liver and excreted in the urine.1

Availability:

  • Ativan™ is available in 0.5 mg, 1 mg and 2 mg tablets.

Dosage:

  • General adult oral minimal sedation dose is 0.5-1 mg.2
  • A single dose of 1-4 mg taken 1 hour prior to bedtime or at the dental appointment will provide adequate anxiety reduction.1
  • RCDSO Standard of Practice:7
  • Minimal sedation: 0.5-1 mg
  • Moderate sedation: 2-3 mg

Drug Interactions:

  • When co-administered with other CNS depressants, including alcohol, opioids, or barbiturates, additive CNS depression may occur.1

Adverse Reactions:

  • The most common side effects include sedation (15.9%), dizziness (6.9%), weakness (4.2%), and ataxia (3.4%).1

Contraindications:

  • Lorazepam is contraindicated in patients with known benzodiazepine sensitivity and with narrow angle glaucoma, similar to other benzodiazepines.1 This medication is not recommended for patients with psychosis or a primary depressive disorder.1

Midazolam (Versed™)

Midazolam is a popular and effective sedative for managing dental anxiety, especially in children, because of its short half-life.1,2 The half-life of midazolam is 1.5-2.5 hours, reaching peak plasma level in 30 minutes following oral administration.1,2 It is metabolized by the liver and excreted in the urine.1

Because it is usually used in children, extra training in the management of sedated paediatric patients is necessary.

Availability:

  • Versed™ is available in 5 mg/mL, which can be mixed with syrup for off-label oral usage.1,2,6

Dosage:

  • For pediatric patients over the age of 6 months, 0.25-0.5 mg/kg of midazolam is recommended to a maximum of 20 mg.1,6

Drug Interactions:

  • When co-administered with other CNS depressants, including alcohol, opioids, or barbiturates, additive CNS depression may occur.1

Adverse Reactions:

  • The most common side effects include drowsiness (14.0%), headache (9.7%), dizziness (7.8%), and nervousness (5.2%).1

Contraindications:

  • Midazolam is contraindicated in patients with heart failure, narrow angle glaucoma, and impaired renal or hepatic function.1

Oral sedation using benzodiazepines is a simple, safe, and effective method of reducing patient anxiety. Gaining a deeper understanding of the options available should allow practitioners to expand their range of services for patients with dental anxiety. For practitioners interested in providing minimal or moderate sedation for their patients in Ontario, continuing dental education training courses are available in various places, including the University of Toronto, Western University, and the Ontario Academy of General Dentistry.

Oral Health welcomes this original article.

References

  1. Malamed, S. F. Sedation: a guide to patient management. (Mosby Elsevier, 2010).
  2. Donaldson, M., Gizzarelli, G. & Chanpong, B. Oral Sedation: A Primer on Anxiolysis for the Adult Patient. Anesth. Prog. 54, 118–129 (2007).
  3. Morlock, E. V. & Czajkowski, C. Different Residues in the GABAA Receptor Benzodiazepine Binding Pocket Mediate Benzodiazepine Efficacy and Binding. Mol. Pharmacol. 80, 14–22 (2011).
  4. Howard, P., Twycross, R., Shuster, J., Mihalyo, M. & Wilcock, A. Benzodiazepines. J. Pain Symptom Manage. 47, 955–964 (2014).
  5. Holstege, C. Benzodiazepines. vol. 1 260–262 (2005).
  6. Griffin, C. E., Kaye, A. M., Bueno, F. R. & Kaye, A. D. Benzodiazepine Pharmacology and Central Nervous System–Mediated Effects. Ochsner J. 13, 214–223 (2013).
  7. RCDSO Standard of Practice Use of Sedation and General Anesthesia in Dental Practice, (November 2018).

About the Author

Dr. Alice Dong completed her dental education from the University of Alberta. Upon graduation, her career goal of improving access to dental care drove her to Tisdale, a small rural town in Saskatchewan. She is passionate for dental anaesthesia and is currently a first-year dental anaesthesia resident at the University of Toronto.

RELATED NEWS

RESOURCES