Volume 7 • 2020 • Issue 2

➜ ➜  Safety recommendations First, be conservative about prescribing drugs, in general. “Remember the four Rs. Right drug, right dose, right patient, right procedure,” says Dr. Donaldson. In deciding whether a patient with dental anxiety would benefit from benzodiazepines, Dr. Donaldson says that it is important to have a current and thorough medical and pharmacological history for that patient. “Also, since 90% of the medications we give tend to be oral, we want to be conservative in our doses,” says Dr. Donaldson. “We want to make sure that we don’t put too much in because if we do give too large a dose, it’s very difficult to get it back out.” He suggests that because sedation dentistry is highly regulated, most practitioners are already practising minimal sedation or the lightest level of sedation, which in most cases includes only a single dose of an oral drug. “In dentistry, what we offer is a one-time dose in order to help make the dental appointment more successful.” And what if the worst happens and a patient who is on an opioid, but didn’t disclose it, takes a benzodiazepine in your dental office? “Benzodiazepines have a very specific reversal agent called flumazenil,” says Dr. Donaldson. “There are seven drugs in the minimal dental emergency kit, but if you do sedation dentistry, you need to add two more: flumazenil to reverse benzodiazepines and Naloxone to reverse opioid overdose.” If a patient arrives at an appointment already on a benzodiazepine, Dr. Donaldson says that any additional treatment for dental anxiety should be done exclusively with nitrous oxide. “Nitrous oxide doesn’t take part in any metabolic processes,” says Dr. Donaldson. “In fact, almost 100% of the nitrous oxide that goes into a patient comes back out. It’s a gas, so it’s quick on, quick off. And it’s the only sedative that we can offer patients where they can drive themselves home.” If a patient is going to need an opioid for post-operative pain, don’t also use a benzodiazepine for dental anxiety, says Dr. Donaldson. “Opioids aren’t a first-line agent anyway,” he says. “A lot of dentists are no longer prescribing opioids. This is yet another reason not to.” References 1. cnn.com/2019/10/04/health/benzodiazepines-this-is-life-with-lisa-ling/ index.html 2. cbc.ca/news/canada/nova-scotia/benzodiazepines-opioids-deaths-nova- scotia-1.4937134 3. Dasgupta N, FunkMJ, Proescholdbell S, Hirsch A, Ribisl KM, Marshall S. Cohort Study of the Impact of High-Dose Opioid Analgesics on Overdose Mortality. Pain Med . 2016;17(1):85-98. Visit CDA Oasis for more on benzodiazepines with Dr. Donaldson: oasisdiscussions.ca/ 2019/11/07/are-benzos- the-next-opioids In deciding whether a patient with dental anxiety would benefit from benzodiazepines, it is important to have a current and thorough medical and pharmacological history for that patient. “One of their unique features is anterograde amnesia,” says Dr. Donaldson. “Unlike retrograde amnesia, anterograde amnesia means that you begin to lose memories as the drug begins to take effect, which is one of the positive characteristics of these drugs from a dental perspective.” Benzodiazepines can be prescribed as a premedication for dental procedures among those with dental anxiety. The drug treats anxiety during the procedure and makes the procedure harder to remember, which often results in less fear at subsequent dental appointments. “Originally, benzodiazepines were available as injectable medications,” says Dr. Donaldson. “Then we started to develop the oral tablets. You could take a high-fear adult dental patient, give them two and a half to five milligrams of Valium, and within about 30 to 45 minutes, they will be relaxed enough to accept dentistry.” Dr. Donaldson says that benzodiazepines also have applications as a muscle relaxant for TMJ patients. “Valium in particular is very long acting,” he says. When it was used as a sleep aid, users were often lethargic the next day. It can take up to 10 days for the drug to be eliminated from the body. For dentistry, a drug with a shorter half-life is often more appropriate. “Triazolam, which has the brand name Halcion, starts working in about 15 minutes and it has a two-hour half-life, so it wears off fairly quickly.”  Treatment for children “Children are unique patients,” says Dr. Donaldson. Midazolam, marketed under the trade name Versed, among others, is a benzodiazepine that induces sleepiness, decreases anxiety, and causes a loss of ability to create new memories. “It works well and is short-acting,” says Dr. Donaldson. “The working time that you typically get from a dental perspective is about an hour, which is usually about as long as you want kids in the chair.” Pediatric specialists warn that, according to the literature, about 10% of children have a paradoxical reaction to benzodiazepines, characterized by increased excitement and excessive movement. “Paradoxical reactions are more common at extremes of age,” says Dr. Donaldson. “My pediatric dentist colleagues say that in their offices the incidence is higher. Maybe 20% or even 30%.” Many pediatric dentists use an antihistamine to help young patients relax. “Benadryl or Atarax (hydroxyzine),” says Dr. Donaldson. “Side effect of these antihistamines include sedation and sleepiness. Antihistamines are a very safe alternative to controlled substances such as the benzodiazepines.”  Hazards of benzodiazepines Dr. Donaldson says that there has been concern about the safety of benzodiazepines expressed in the media for decades. “It is not new,” he says. “And the drugs themselves are not new, either.” Between 1969 and 1982, Valium was the most prescribed drug in the US, with over 2.3 billion doses sold at its peak in 1978. He suggests that dental professionals be vigilant about the dangers of combining benzodiazepines with other prescription or non-prescription drugs. “Benzodiazepines in and of themselves are some of the safest drugs we have,” says Dr. Donaldson. “They have a very large inherent margin of safety.” Dr. Donaldson says that benzodiazepine overdoses don’t often cross the line of mortality unless they are mixed with another central nervous system depressant, such as alcohol or opioids. Opioids, benzodiazepines, and alcohol all suppress breathing, which is the cause of overdose fatality. A 2016 cohort study in North Carolina found that the overdose death rate among patients receiving both opioids and benzodiazepines was 10 times higher compared to those who only received opioids. 3 Also in 2016, the Centers for Disease Control and Prevention (CDC) issued new guidelines that recommend that clinicians avoid prescribing benzodiazepines concurrently with opioids whenever possible. First, be conservative about prescribing drugs, in general. “Remember the four Rs. Right drug, right dose, right patient, right procedure.” S upporting Y our P ractice 39 Issue 2 | 2020 | 38 | 2020 | Issue 2