CH 12

CNS Depressants: Benzodiazepines

*Benzodiazepines* were historically the most commonly prescribed drug in this classification. *Nonbenzodiazepines are currently more frequently prescribed.

Which statement regarding muscle relaxants does the nurse identify as being accurate? A.Baclofen (Lioresal) is available as an injectable form for use with an implantable pump device. B.Cyclobenzaprine (Flexeril) produces little sedation. C.Patients taking muscle relaxants are at high risk of developing hypertension. D.Patients taking muscle relaxants should be told to stop taking the medication if they feel sleepy.

A.Baclofen (Lioresal) is available as an injectable form for use with an implantable pump device. Baclofen (Lioresal) is sometimes used in an injectable form. Cyclobenzaprine (Flexeril) often results in deep sedation and sleepiness. Patients taking muscle relaxants are at risk to develop hypotension; therefore, they should be taught safety measures to prevent falls. Sedation and sleepiness are common side effects of muscle relaxants; however, a patient should not abruptly discontinue use of the medication. Safety procedures should be followed to prevent accidents and falls.

The patient tells the nurse that his friend has been taking valerian for a long period of time and that he isn't feeling so well. The patient asks the nurse what the adverse effects of valerian are. 2. What adverse effect with valerian would the nurse discuss with the patient? A.Insomnia B.Yellow skin C.Bruising D.Increased appetite

A.Insomnia Adverse effects of valerian include CNS depression, hepatotoxicity, nausea, vomiting, anorexia, headache, restlessness, and insomnia.

An older adult patient taking multiple medications has a barbiturate added to his medication regimen. When administering a barbiturate to an older adult, what should the nurse expect? A.A decrease in dosages of the other medications B.The patient will experience increased amounts of REM sleep C.To administer half of the usual dose of the barbiturate D.Total relief of anxiety

ANS: C Barbiturates are associated with an increased incidence of falls when used in older adults; therefore, the usual dose is reduced by half whenever possible. Because barbiturates stimulate the action of enzymes in the liver, drugs are usually broken down more quickly, sometimes requiring the dose to be increased. Patients taking barbiturates have decreased amounts of REM sleep and often experience paradoxical restlessness or excitement.

1. The patient asks, "Is there anything I have to worry about when taking Kava?" The best response by the nurse is: A."Kava is a natural product which has no side effects." B."You need a prescription to take Kava." C."No worries, Kava is recommended for patients with depression." D."It is best to inform your health care provider of any additional medication or supplements you plan to take to check for interactions that may be harmful."

ANS: D Even natural products have side effects. Side effects of Kava include skin discoloration, possible accommodative disturbances and pupillary enlargement, and scaly skin (with long-term use). Kava and other supplements are available without a prescription. Kava is contraindicated in patients with Parkinson's disease, liver disease, depression, or alcoholism; in those operating heavy machinery; and in pregnant and breastfeeding women. As with all medications and supplements, it is best to inform the health care provider to evaluate possible interactions among drugs and supplements taken.

When providing education to the patient on the use of a benzodiazepine medication, the nurse will include which information? A.These medications have little effect on the normal sleep cycle. B.Using this medication may cause drowsiness the next day. C.It is safe to drive while taking this medication. D.These drugs are safe to use with alcohol.

B.Using this medication may cause drowsiness the next day. Benzodiazepines interfere with REM sleep and may cause a "hangover" effect or next-day drowsiness. They should not be used with alcohol, and persons taking these drugs should not drive.

Barbiturates adverse effects

Cardiovascular Vasodilation, hypertension CNS Drowsiness, lethargy, vertigo Respiratory Respiratory depression, cough GI Nausea, vomiting, diarrhea, constipation Hematologic Agranulocytosis, thrombocytopenia Other Hypersensitivity reactions, Stevens-Johnson syndrome

Hypnotics

Cause sleep Much more potent effect on CNS than sedatives A sedative can become a hypnotic if it is given in large enough doses.

Kava contraindications

Contraindicated in liver disease, alcoholism, other conditions

Benzodiazepines:Mechanism of Action

Depress CNS activity Affect hypothalamic, thalamic, and limbic systems of the brain Benzodiazepine receptors Gamma-aminobutyric acid (GABA) Do not suppress rapid eye movement (REM) sleep as much as barbiturates do Do not increase metabolism of other drugs

Benzodiazepines: Contraindications

Drug allergy Narrow-angle glaucoma Pregnancy

Sedatives

Drugs that have an inhibitory effect on the CNS to the degree that they reduce: Nervousness Excitability Irritability

Diazepam (Valium)

First clinically available benzodiazepine drug. It has varied uses Treatment of anxiety Procedural sedation and anesthesia adjunct Skeletal muscle relaxation Available in multiple forms: Oral Rectal Injectable

Benzo antidote

Flumazenil (Romazicon)

Kava

Herbal Antianxiety Agent Used to relieve anxiety, stress, and restlessness and to promote sleep May cause temporary yellow skin discoloration (extended, continued intake) and visual disturbances Potential interactions with alcohol, barbiturates, and psychoactive drugs Contraindicated in liver disease, alcoholism, other conditions Patient should not operate heavy machinery during use.

Temazepam (Restoril)

Intermediate-acting benzodiazepine One of the metabolites of diazepam Normally induces sleep within 20 to 40 minutes Long onset of action, so it is recommended that patients take it about 1 hour prior to going to bed Still an effective hypnotic; however, it has been replaced by newer drugs

Benzodiazepines: Adverse Effects

Mild and infrequent: Headache Drowsiness Dizziness Cognitive impairment Vertigo Lethargy Fall hazard for older adults "Hangover" effect or daytime sleepiness

Midazolam (Versed)

Most commonly used preoperatively and for moderate sedation Causes amnesia and anxiolysis (reduced anxiety) as well as sedation Normally administered by injection in adults Liquid oral dosage form is also available for children.

Barbiturates: Toxicity and Overdose

Overdose frequently leads to respiratory depression and subsequent respiratory arrest. Overdose produces CNS depression (sleep to coma and death). Can be therapeutic Anesthesia induction Uncontrollable seizures: "phenobarbital coma"

Benzodiazepines: Indications

Sedation Sleep induction Skeletal muscle relaxation Anxiety relief Anxiety-related depression Treatment of acute seizure disorders Treatment of alcohol withdrawal Agitation relief Balanced anesthesia Moderate or conscious sedation

Barbiturates have a low therapeutic index. How does the nurse interpret this? A.Low doses are not therapeutic. B.The toxic range is narrow. C.They are habit forming. D.The effective, safe dosage range is narrow.

The effective, safe dosage range is narrow. Drugs with a low therapeutic index have only a narrow dosage range within which the drug is effective; above that range, they are rapidly toxic. Barbiturates are habit forming, but this is not related to the therapeutic index.

Barbiturates:Toxicity and Overdose (Cont.) Treatment of overdose uS

Treatment of overdose Symptomatic and supportive Maintain adequate airway Assisted ventilation or oxygen therapy Fluids Pressor support Activated charcoal

Common Muscle Relaxants

baclofen (Lioresal) cyclobenzaprine (Flexeril) dantrolene (Dantrium) metaxalone (Skelaxin) tizanidine (Zanaflex) carisoprodol (Soma) chlorzoxazone (Paraflex) methocarbamol (Robaxin)

Barbiturates

drugs that depress the activity of the central nervous system, reducing anxiety but impairing memory and judgment