Chapter 12
CNS Depressants & Relaxants
CNS Depressants & Relaxants
Name 2 main groups of CNS depressants.
- Benzodiazepines (suffix "-pam")
- Barbiturates
Name a drug used to treat ADHD.
methylphenidate (Ritalin)
Note: This drug is also used to treat narcolepsy.
What is the black box warning for antiepileptic drugs?
Suicidal thoughts and behavior
What is the cause of Parkinson's Disease?
It is thought to be caused by an imbalance of dopamine and acetycholine (ACh).
Name one class of drugs used for the treatment of anxiety.
Benzodiazepines (CNS depressant)
What conditions do benzodiazepines treat?
- Anxiety disorders
- Acute seizures
What drug class does methylphnidate belong to?
Amphetamines
Name 4 antiepileptic drugs.
- phenytoin
- gabapentin
- carbamazepine
- valproic acid
What are some adverse effects of levodopa-carbidopa therapy?
- cardiac dysrhythmias
- hypotension
- dizziness
What should a patient avoid while taking a benzodiazepine?
Alcohol or other sedatives.
Name some contraindications to the use of benzodiazepines.
- Narrow-angle glaucoma
- Pregnancy
What is a common adverse effect of methylphenidate?
Anorexia
What are some adverse effects with the antiepileptic drug phenytoin?
- gingival hyperplasia
- osteoporosis
Why are anticholinergics sometimes prescribed with Parkinson's Disease?
- They block the effects of acetylcholine.
- They are used to treat muscle tremors and muscle rigidity associated with PD.
**Note: Muscle tremors and muscle rigidity are caused by excessive cholinergic activity.
What drug is used to reverse the effects of benzodiazepines?
flumazenil
What is one adverse effect of benzodiazepines that you would want to educate your patient about?
They can cause a "hangover" effect or daytime sleepiness.
**Fall hazard for older adults
What should you educate your patient about regarding methylphenidate?
- Methylphenidate is a stimulant:
** It should be taken in the morning.
** Caffeine intake should be restricted.
What is the therapeutic drug level for phenytoin?
10 to 20 ug/mL
What is the saying used to describe the action of anticholinergics?
"Can't see, can't pee, can't spit, can't sh__t"
What condition does lithium treat?
Mania
What is the overdose treatment (antidote) for benzodiazepines?
Flumazenil
**NOTE: Benzodiazepines do not cause hypotension and respiratory depression unless taken with other CNS depressants.
Name a drug that is commonly prescribed for narcolepsy.
- modafinil
What adverse reactions can occur with carbamazepine?
- unusual eye movements
- behavioral changes
- dizziness
Name one anticholinergic drug used for the treatment of Parkinson's Disease?
benztropine
Lithium has a narrow therapeutic range. What are the maintenance serum levels (range) for ongoing lithium treatment?
Between 0.6 and 1.2 mEq/L
1. Name a CNS depressant that is for the short-term management of insomnia.
2. What pregnancy category is this drug?
1. temazepam
2. Pregnancy category D
What drug class does modafinil belong to?
It is a nonamphetamine stimulant, so there is less abuse potential than with amphetamines and methylphenidate.
Which antiepileptic drug should not be taken with grapefruit?
Carbamazepine
What is the expected therapeutic effect with benztropine?
Patients should experience a decrease in tremors.
What symptoms can a patient experience with lithium toxicity?
Nausea, vomiting, diarrhea, tremor, confusion, seizures.
Why are benzodiazepines preferred over barbiturates?
Barbiturates are habit forming and have a low therapeutic index.
Name a drug that is used to treat obesity.
- phentermine (it is an anorexiant)
Gabapentin has multiple uses. In addition to epilepsy, what other condition does it treat?
Neuropathy
What should patients be taught about discontinuing antiparkinson drugs?
These drugs should not be discontinued suddenly.
What should a patient do if they begin to experience symptoms of lithium toxicity?
Call their provider
What are contraindications to the use of barbiturates?
- pregnancy
- significant respiratory difficulties
- severe kidney or liver disease
What is the MOA of phentermine?
It suppresses appetite.
What are the most serious adverse effects associated with valproic acid?
- hepatotoxicity
- pancreatitis
What part does sodium play in keeping lithium levels within the therapeutic range?
A loss of sodium (i.e., from diarrhea/dehydration or from a low-sodium diet) will cause lithium levels to increase, which may lead to lithium toxicity.
**Keeping the sodium level in the normal range helps maintain therapeutic lithium levels.
How is an overdose of barbiturates treated?
Unlike the benzodiazepines, an overdose of barbiturates frequently leads to respiratory depression and respiratory arrest.
- Overdose treatment involves:
* maintaining an adequate airway
* assisted ventilation or oxygen therapy
What are some contraindications to the use of anorexiants?
- severe cardiovascular disease
- uncontrolled HTN
- hyperthyroidism
(Remember, anorexiants are stimulants and speed up metabolism.)
What are some things you should teach your patient who is taking an antiepileptic drug?
- Antiepileptic drugs should not be discontinued abruptly.
- Therapy is long term and possibly lifelong (not a cure).
- If taking phenytoin, perform mouth care several times per day due to the adverse effect of gingival hyperplasia.
What is the most serious adverse effect associated with lithium?
Cardiac dysrhythmia.
What adverse effects can occur with muscle relaxants?
- euphoria
- dizziness
- drowsiness/sedation
1. What time of day should an anorexiant be taken?
2. What should the patient avoid while on this medication?
1. In the morning
2. Avoid caffeine
What is the MOA of tricyclic antidepressants?
They block reuptake of neurotransmitters, causing accumulation at the nerve endings.
** Increasing concentrations of neurotransmitters can correct the abnormally low levels that lead to depression.
What are the interactions to watch for with muscle relaxants?
Caution with other CNS depressants:
- benzodiazepines
- alcohol
What disorder do the drugs ending in "-triptan" treat?
Migraine headache
Why are patients with anorexia nervosa sometimes prescribed a tricyclic antidepressant (TCA)?
TCAs increase appetite
Name some adverse effects associated with tricyclic antidepressants.
- Impotence
- Orthostatic hypotension
- Dysrhythmias
What should you educate a patient about who is taking a MAOI (monoamine oxidase inhibitor) for depression?
- Avoid foods that contain tyramine (remember, picnic foods: aged cheese, smoked meat, red wine, fava beans).
**NOTE: Ingesting foods with tyramine leads to hypertensive crisis, which may cause cerebral hemorrhage, stroke, coma, or death.
- Patients taking MAOIs are at risk for orthostatic hypotension.
- Do not take St. John's Wort when taking an MAOI.
1. What drug class does fluoxetine belong to?
2. Name a drug that was originally for treatment of depression, but is now also used in smoking cessation.
1. Selective serotonin reuptake inhibitors (SSRIs)
**SSRIs are second-generation antidepressants
2. bupropion
What adverse effects and contraindications are associated with fluoxetine?
Adverse effects:
- anxiety
- dizziness
- sexual dysfunction
Contraindications:
- Do not take fluoxetine with either an MAOI or with St. John's Wort.