Sedative-Hypnotics, Antianxiety, and Antidepressant Drugs Flashcards
What must drugs who are targeted for the CNS be able to do?
Drugs must be able to pass through the blood-brain barrier by either diffusion or being chemically modified in order to pass through
Purpose of Neurotransmitters
Neurons release neurotransmitters in order to cause either excitation or inhibition of other neurons
Examples: AcH, amino acids, peptides
What do Sedative-Hypnotics and Antianxiety drugs do?
Produce a calming and relaxing effect by depressing the CNS on the patient, where larger doses can produce drowsiness or sleep
What are the two categories of Sedatives?
- Benzodiazepines
- Nonbenzodiazepines
Both are used to promote sleep
Why use Benzos over NonBenzos?
Benzos are mostly used for anxiety, but they also promote sleep and are considered safer than NonBenzos due to a smaller chance of lethal overdoes
Benzo Mechanism of Action
Increases the inhibition at the CNS synapses that use the neurotransmitter GABA
-GABA causes inhibition of the CNS which results in relaxation and feelings of decreased anxiety
What is the primary neurotransmitter that causes inhibition of neurons within the CNS?
GABA- so an increase in GABA results in CNS relaxation
Indications of Benzos
-sleep hypnotics
-anxiety
-decreases seizures
-general anesthesia
-muscle relaxation
Side Effects of Benzos
-drowsiness/sedation (most common)
-decreased motor response
-hang-over effect
-anterograde-amnesia
-rebound anxiety
-drug abuse/addiction
**can occur the next day
What are NonBenzos used for?
-sedation
-hypnosis
-general anesthesia
Side effects of NonBenzos
-VERY addictive
-drug abuse
-hang-over effect
What are the properties of barbiturates?
CNS depressants with potent sleep-hypnotic properties
-very small TI
-very addictive and leads to prolonged drug abuse
-NOT commonly used
Examples: Nonbenzos
NonBenzo Mechanism of Action
Binds to GABA receptors to increase inhibition of CNS- same as benzos
Benzo and NonBenzo endings
Benzo: ending in -am (flurazepam, estazolam)
NonBenzo: ending in -al (amobarbital, phenobarbital)
What are the benefits of using drugs that can act as sedatives and hypnotics but are not actually Benzos or Nonbenzos?
These drugs have been developed where they still affect GABA receptors in the brain but NOT in the same way as Benzos or NonBenzos. They have a shorter duration and shorter half-life but they do not causes a hang-over effect.
Examples: Ambien
What are the benefits of using drugs that can act as sedatives and hypnotics but are not actually Benzos or Nonbenzos?
These drugs have been developed where they still affect GABA receptors in the brain but NOT in the same way as Benzos or NonBenzos. They have a shorter duration and shorter half-life but they do not causes a hang-over effect.
Examples: Ambien
Which compounds can cause sedation-hypnosis effects?
-alcohol
-antihistamines
-antidepressants
-antipsychotics
-anticonvulsants
-opioid analgesics
Pharmacokinetics of Sedation-Hypnotic Drugs
-very lipid soluble: able to pass through BBB
-administered orally
-absorbed from GI tract
-distributed uniformly throughout body
-metabolized in liver
-excreted through kidneys
Overall Side Effects for sedative drugs
-tolerance and dependence can occur
-sleep walking
-sleep driving
-compulsive eating while sleeping
-GI discomfort
-dry mouth
-sore throat
-muscular incoordination
Drugs used to treat anxiety
-Benzos
-Buspirone
-Antidepressants
-others: beta blockers
Most common Benzo used for Anxiety
Diazepam (Valium): increases inhibition in the SC that produces skeletal muscle relaxation and contributes to one feeling relaxed and less anxious
Who should NOT use Benzos?
Benzos are not good for the elderly because of the sedation effect they can cause memory and confusion problems. Should also not be used for those who need long-term treatment due to addiction side effects.
When and when not to use Buspirone
Good for patients who need long-term treatment of anxiety, however it only has moderate efficacy and may not be effective in those with severe anxiety
Benefits and Side Effects of Buspirone
Benefits:
-less sedation and psychomotor impairments compared to Benzos
-small risk of tolerance and dependence
-low risk of abuse
Side Effects:
-HA
-dizziness
-nausea
-restlessness
-hypothermia
Buspirone Mechanism of Action
Increases the effects of the neurotransmitter Serotonin
Benefits of taking Antidepressants for Anxiety
Antidepressants can have anti anxiety effects and will typically have less side effects and low risk of addiction making them an effective way to treat anxitey
How do Beta Blockers treat Anxiety?
They decrease anxiety by blocking the sympathetic nervous system. Plus they are able to decrease anxiety without causing sedation
Why should PTs be cautious when working with older adults on sedative or anxiety drugs?
Older adults on these meds are at risk for increased falls so it is important we use gait belts and include balance training and fall prevention strategies during treatment
How do Antidepressants help with depression?
When someone is depressed there is a disturbance in the CNS involving amine neurotransmitters (serotonin, NE, and dopamine). Antidepressants work by increasing amine transmission.
What are the categories of Antidepressants?
-Selective serotonin reuptake inhibitors (SSRI)
-Serotonin-norepinephrine reuptake inhibitors (SNRI)
-Tricyclics
-Monoamine Oxidase Inhibitors (MOA)
-other compounds
How long do Antidepressants take to work?
2-4 weeks. Make sure patients understand that this is going to be a lag time before they begin to feel a difference
SSRI Mechanism of Action
These antidepressants work by blocking the reuptake of serotonin into the synaptic terminal throughout the brain and allows serotonin to remain in the synaptic cleft to exert its effects longer
What is the key amine neurotransmitter to help regulate mood and depression?
Serotonin
Benefits of taking SSRIs
SSRIs are selective for serotonin only and therefore patients will have a greater effect and less side effects due to the selectivity of this drug
How do SNRIs work in treating depression?
This drugs work to decrease the reuptake of serotonin and norepinephrine into the synaptic terminal which allows them to remain for longer periods
Are Tricyclics a selective drug?
No. Tricyclics work to treat depression by blocking and reuptake of all the amine neurotransmitters: serotonin, NE, and dopamine
Which Antidepressant used to be the gold standard and which is considered the gold standard now?
Tricyclics used to be the gold standard for depression until SSRIs were developed due to their selectivity effect
How do Monoamine oxidase Inhibitors (MAOs) work?
MAOs inhibit the enzyme monomine oxidase. This enzyme removes neurotransmitters from synapses. By inhibiting those enzymes, it allows the amine neurotransmitters to have an effect.
Which antidepressant should not be taken with foods that contain tyramine?
MAOs can be very dangerous if taken with these foods. They are also not the first choice for depression since they have a lot of side effects
Pharmacokinetics of Antidepressants
-taken orally
-dose begins small and is slowly increased until effects are seen
-all reach the brain
-metabolized in liver
-biotransformation and renal excretion for elimination
What are the most common symptoms of SSRIs and SNRIs?
GI symptoms: n & v, diarrhea, constipation
What is the most serious side effect of SSRIs and SNRIs?
Serotonin Syndrome: a serotonin build up in the brain
Symptoms: sweating, agitation, restlessness, shivering, tachycardia, neuromuscular hyperexcitability (tremors, clonus, hyperreflexia, rigidity, fasciculations), seizures, coma, death
**this is a medical emergency and drug should be discontinued immediately if any of the above symptoms are present
Tricyclics Side effects
-Sedation, lethargy, and sluggishness
-anticholinergic effects (cant see, cant pee, cant poop)
-confusion
-arrhythmias (can be fatal)
-orthostatic hypotension
-muscle weakness
MAOs side effects
-CNS excitation: restlessness, agitation, sleep loss (the opposite effects of tricyclics)
-increase in BP
-dangerous if taken with foods containing tyramine
Other than anxiety and depression, what else are antidepressants effective in treating?
Many chronic pain syndromes: neuropathic pain, fibromyalgia, chronic LBP
What causes Bipolar Disorder?
an imbalance between inhibitory neurotransmitters and excitatory neurotransmitters
What is the primary drug used to treat bipolar disorder?
Lithium. It influences neuronal excitability and neuronal function
How is lithium metabolized and excreted?
Lithium is not metabolized and it is excreted only in the urine. This may cause possible lithium accumulation in the body or lithium toxicity
What other forms of medications are beneficial for bipolar disorder?
Anti-seizure meds and antipsychotic meds because they help to stabilize mood and limit manic episodes
Side effects of Lithium
-sedation
-lethargy
-muscle weakness
**make sure to be aware of lithium toxicity symptoms
Lithium Toxicity Symptoms
CNS: hand tremor, slurred speech, blurred vision, ataxia, fasiculations, seizures
GI: nausea, loss of appetite, diarrhea, vomiting, abdominal pain
Cardiovascular: ECG changes, bradycardia, AV block, arrhythmias
Renal: polyuria, renal insufficiency, kidney damage
