Benzodiazepines Completely Simplified
One of the most common and often-prescribed drug classes is that of benzodiazepines. In fact, we use them so much you may simply hear them referred to as “benzos.” They are one of many classes of medications that depress the central nervous system…others include barbiturates, opioids and sedative-hypnotics.
Note that “benzodiazepine” is the pharmacologic class. They can also be classified by therapeutic effect and are in the therapeutic classes of analgesics, anticonvulsants, muscle relaxants, antianxiety agents and sedatives/hypnotics.
How do benzodiazepines work?
Benzodiazepines depress the central nervous system by potentiating the effects of GABA, an inhibitory neurotransmitter. Remember, when we ENHANCE an INHIBITORY function, we are putting on the brakes. Benzos put the brakes on the CNS!
What are some common benzodiazepines and what are they used for?
One of the first things you’ll notice is that MOST benzos end in “-am”…not all, but many do. Chlordiazepoxide (Librium) was one of the first benzos, along with diazepam (Valium). Others include alprazolam (Xanax), lorazepam (Ativan) and midazolam (Versed). Regardless of which one you use, they all act the same way and have the same adverse effects. The key difference is the onset of action and how long they exert their influence. The fastest-acting is midazolam, whereas halazepam (Paxipam) takes up to three hours to reach maximum effect. Diazepam and alprazolam, when taken PO, have an onset of about 60 minutes but can last up to 24 hours. Another really common one, lorazepam, lasts about 12 hours when taken by mouth. So, it’s important to know which benzodiazepine your patient is taking so that you know how long they’ll require monitoring for related adverse effects.
Benzodiazepines are indicated for a variety of conditions, and are somewhat specific to the purpose for their use. For example, the benzos used for insomnia are typically different than those used for generalized anxiety disorder. Below is a general list of which medications are used for specific reasons, but note that it’s not a hard-and-fast rule. The MD may prescribe something different that works better for that individual.
- Insomnia: temazepam (Restoril). It has an onset of 30 minutes and a duration of 6-8 hours, making it perfect for sleep.
- Anxiety: lorazepam (Ativan) or diazepam (Valium)
- Panic disorder: alprazolam (Xanax) or clonazepam (Klonopin)
- Seizures: diazepam (Valium), lorazepam (Ativan) and clorazepate (Tranxene)
- Muscle relaxant: diazepam (Valium)
- Anesthesia: midazolam (Versed), may also see lorazepam (Ativan) or diazepam (Valium)
- Alcohol withdrawal: chlordiazepoxide (Librium) – This will be dosed based off something called the CIWA score which measures the severity of the alcohol withdrawal symptoms. You could also see Tranxene used for alcohol withdrawal symptoms as well. You can learn more about caring for patients going through alcohol withdrawal here (link to alcohol withdrawal post).
Like any other CNS depressant, benzodiazepines have potential for abuse, so they are a Schedule IV controlled substance. According to American Addiction Centers, alprazolam is one of the most addictive of the benzos currently in use. The risk for alprazolam addiction is higher in those taking more than 4mg/day for a duration of more than 12 weeks. However, anyone who abuses medications such as benzodiazepines is at risk for addiction.
As a regulated substance, there are a few guidelines you’ll notice when working in the clinical setting. For starters, you’ll need to count the number of pills or vials every single time you get any of these medications from the Pyxis (or whatever system you use). You’ll also need to waste any leftover with another licensed individual…either an RN, NP or an MD. I’m assuming a PA could waste with you as well, but what we typically do is waste with another RN. The other key factor you’ll notice is that patients are often prescribed only a small number at any given time.
Is tolerance the same as addiction or abuse?
You will certainly hear the term “tolerance” a lot when working with patients, especially when you’re talking about medications like opioids and, yes…benzodiazepines. Tolerance occurs when the individual requires higher and higher doses of a medication in order for it to have the desired effect. It is a very common issue with medications that affect the central nervous system. Just because someone’s BODY has developed a physiological tolerance to a medication does not mean they are addicted or abusing the substance.
Guidelines for safe benzodiazepine administration
Before you give a benzodiazepine, you’ll want to assess the patient for any contraindications. These include hypotension, decreased LOC, sleep apnea and angle-closure glaucoma among others. For a complete list, please refer to your drug guide.
You’ll also want to use them cautiously in a variety of circumstances such as COPD, severe renal or liver disease, history of suicidal ideation/attempt, a concurrent substance abuse disorder or advanced age. You will often hear the phrase “start low and go slow.” That’s how a lot of medications are dosed when treating geriatric patients. Benzos are also used cautiously in children, and the only time I’ve ever seen them used in that population is for seizures.
Most benzodiazepines are PO medications, with some given IV. Diazepam (Valium) can be given as a suppository, which is a common method for patients having seizures and who do not have IV access.
Your assessments when administering benzodiazepines include:
- Monitor respiratory status – Benzos can reduce respiratory drive in some patients (such as those with sleep apnea) and exacerbate the respiratory depression of opioids. Be very careful when giving benzos along with opioids! Snoring should not be ignored, especially in patients who don’t normally snore. While we tend to think of snoring as an annoyance, it is actually a partial airway obstruction. The patient may need repositioning or an OPA/NPA.
- Monitor neurological status/LOC – As a CNS depressant, benzodiazepines can definitely lead to decreased LOC, especially when too high a dose is taken, or when taken in conjunction with another CNS depressant such as an opioid or even when taking with an antihistamine such as diphenhydramine.
- If mom is taking benzos while pregnant, the infant will need to be monitored for at least a few weeks (possibly longer) for signs of withdrawal
Patient teaching for benzodiazepines
Some key factors to include in your patient teaching include:
- Avoid alcohol while taking benzodiazepines
- Avoid other CNS depressants unless prescribed to be taken together
- The medication does not treat the underlying anxiety disorder, it just addresses the symptoms.
- Avoid breastfeeding while taking benzos as they can make the baby too drowsy and interfere with effective feeding.
- Avoid abrupt discontinuation. If benzos are used habitually for an extended period of time, the patient should speak to their MD about tapering off the medication.
Adverse effects of benzodiazepines
The most common adverse effects are related to CNS depression, which makes sense, right? These include drowsiness, lethargy and dizziness. Be aware that with rapid IV infusion, benzodiazepines can cause cardiac arrest and apnea, so be very careful when giving through an IV.
What are the side effects of benzodiazepine withdrawal?
The reason you want your patients to taper off extended-use benzos is because of the risk for withdrawal symptoms, which are going to be worse if they stop abruptly. These include headache, restlessness, insomnia, nausea, abdominal pain, light sensitivity, sound sensitivity, muscle twitches, fatigue…..and can even cause seizure.
If you’ve listened to my psychopharmacology podcast episode, I share with you some really goofy stories for remembering the side effects and key information for psychopharmacology. The story for benzodiazepines involves Benzo the Clown and key elements of the story relate to a key adverse effect (shown in bold). Using a tactic like this might help you remember this important information for your exam or the next time you administer a benzodiazepine:
Benzo the clown, like most clowns, was very tolerant of small children. Though, truth be told, they made him extremely tired. One day, he decided to stop seeing the children completely. “I’m done with this headache” he said. But once he got home he realized he missed the kids and he stayed up all night thinking about them. The next day he skipped breakfast, which made him feel dizzy, but he didn’t care. He ran so fast to see the kids that he got dizzy, fell down, hit his head and had a seizure.
I hope that helps you understand this common class of medications and that you feel more confident the next time you see one on an exam or in a clinical setting.
Study this topic on the go in episode 151 of the Straight A Nursing podcast! Listen wherever you get your podcast fix or stream it from here.
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