Transcript Antidepressants Sedatives

Pharmacology –
Unit 2 – Spring 09
Carla Hilton, MSN, RN, CNE
Lecture 2: Chapters 32, 34 & 37
Learning Outcomes
• Compare and contrast fundamental
concepts related to the use of specific
central nervous system drugs for sedation
and depression with a look at major
concepts related to abuse.
• Acquire a working framework for studying
drug classifications and nursing
implications.
Classification:
Antidepressants
Chapter 32
General Points
• Most common psychiatric disorder
• Major treatment method - medications
– Five major groups
• Goal? (to make people feel better/functional)
• Sxms
– Depressed mood, loss of pleasure / interest in all or
nearly all of one’s usual activities
• Under-treated
• More prevalent in women
• Suicidal thoughts may increase w Rx
Tricyclic Antidepressants (TCAs)
• Prototype: imipramine [Tofranil]
• MOA – TE / Use
– Blocks reuptake of the MAO transmitters NE (norepinephrine) and
serotonin. Elevates mood, thereby treating depression. (it doesn’t get
dissolved as quickly, keep producing it’s effect.)
– Other uses: bipolar disorder, neuropathic pain, insomnia,
fibromyalgia, OCD, bladder disorders
– Just b/c they’re taking this, doesn’t mean they are depressed…
• Adverse effects
– Orthostatic hypotension, sedation, anticholinergic effects
(neurotransmitter effects), sedation, diaphoresis, cardiotoxicity,
seizures, hypomania (they aren’t very interactive with you,
“yawngasm”- orgasm that happens when you yawn
– Because it effects neurotransmitters, it has an effect over the entire
body
14-2
Anticholinergic Effects
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Salivary glands- decreased secretion
Sweat glands- decreased secretion
Bronchial glands- decreased secretion
Heart- Increased rate
Eye- mydriasis, blurred vision
Urinary tract- interference with voiding
Intestine- decreased tone and motility
Lung- dilation of bronchi
High Doses
Stomach- decreased acid secretion
TCAs
• Precautions / Interactions
– TCAs w MAOI can lead to severe HTN
– Potentiates drugs like NE (norepinephrine)
– Potentiate CNS depressants
• Antidote: activated charcoal after gavage (go in and
wash out the stomach and wash all the pills out)
• Dosing
– Based on clinical response – don’t give more than a week supply
(so they won’t take them all…)
– Dose at bedtime once levels achieved – EXCEPT in elderly
(cardiac reasons) (when you’re vertical the fluids in your body
they migrate down your body. When you’re laying down the
fluids all go back into the system)
SSRI Antidepressants
• Prototype: fluoxetine [Prozac]
• MOA / TE / Use
– Selective serotonin re-uptake inhibitor resulting in elevated
serotonin levels – elevating mood and relieving depression.
– Helps in bulimia nervosa
• Adverse effects
– Impotence, weight gain, Serotonin syndrome (can make you
agitated and angry), withdrawal syndrome, EPS (extraperamital
side effects), bruxism (grinding your teeth), bleeding,
hyponatremia.
• Interactions: MAOIs, Warfarin (adverse effect of bleeding
in SSRI, warfarin thins blood, they bleed lots), & TCAs
MAOI Antidepressants
• Prototype: phenelzine [Nardil]
• MAO / TE / Use
– Enzyme – deactivates NE, serotonin, dopamine, and tyramine (NE
stimulator) from foods
– NOT 1st CHOICE b/c it causes lots of stimulation
– Use when all other anti-depression meds don’t work
• Relevant P-kinetics
– Tyramine
• Adverse effects:
– CNS stimulation – agitation – hypomania – mania – hypotension –
HTN crisis – meperidine (demerol) (hyperpyrexia)
– You have to cut lots of good foods out of your diet, so the pt
wouldn’t really want to take this.
Atypical Antidepressants
• Bupropion [Wellbutrin]
– Action unclear- often used in smoking
cessation
– Effect
• Stimulant ergo no wt gain
• No sexual dysfunction – may augment
• Adverse effects:
– agitation, HA, dry mouth, constipation, wt loss,
insomnia, tachycardia, seizure
• Note: St. John’s Wort Box 32-2
Nursing Implications
ATI p. 203 (220)
Classification:
Sedative-Hypnotics
Chapter 34
Overview
• Venacular
– Anti-anxiety, anti-anxiolytics, tranquilizers
– Hypnotics
• Major Categories
– Benzodiazepines, Barbiturates, Barbiturate–Like
– Miscellaneous
• Major Effects
– CNS depression (the whole head translates down to
the whole body)
• Therapeutic Uses
– Relieve anxiety, facilitate sleep, manage muscle
spasms, seizure and panic disorders, augment
anesthesia, and manage ETOH withdrawal
Benzodiazepines (CIV)
Category D
• Prototype: diazepam [Valium]
– Others: clonazepam, lorazepam, clorazepate
• MOA
– Depress neuronal function at multiple CNS sites by
potentiating endogenous GABA (gammaaminobutyric acid) and is limited because GABA is
finitesafer
– Cardiac
• Very safe PO, effect - heart & blood vessels
• IV effect – if given rapidly can cause super BP
lowering
– Respiratory
• Minimal alone, serious if combo or IV
• Incompatible with everything in some forms!
Benzos (cont’d)
• Pharmacokinetics:
– Readily absorbed
– Differ in respect to time - course of action
• (main indicator for which one chosen for which job)
• Adverse effects
– CNS – daytime vs nighttime impacts
– Amnesia (usually good b/c they don’t remember the traumatic
procedure)
– Paradoxical (it gets the opposite effect you were expecting)
– Abuse
– Malnutrition (low albumin means higher level of circulating drug),
liver disease and blood levels
• DD w other CNS depressants
• Dosage: varies by agent
Nursing Implications
• ATI pp. 218
Benzodiazapine-likes
• Prototype: Zolpidem [Ambien] CIV (class 4)
• MOA – TE / Use
– Agonists at benzodiazepine receptor site on GABA
channel prolonging sleep duration and helps relieve
insomnia
– Low potential for tolerance or abuse
• Adverse effects
– Similar to benzodiazepines (daytime drowsiness /
dizziness)
– Can intensify CNS depressants
• Dosage / Administration
– Before bedtime, you want it to kick in by the time you
get into bed
– Sleepwalking problems and such
Melatonin Agonist
• Prototype: ramelteon [Rozerem]
• MOA / TE / Use
– Activates melatonin receptors and rapidly induces
sleep to treat insomnia (melatonin causes sleepiness)
• Adverse effects
– Somnolence (you’re kind of apathetic), dizziness, and
fatigue, reduced libido
• Precautions…
– ETOH, liver impairment, dangerous activities
Barbiturates
• Prototype: secobarbital [Seconal]
• MAO / TE / Use
– Mimics GABA and depresses CNS directly causing relaxation
and anxiety reduction. Other uses: seizure management,
anesthesia, sleep disorders, mania
• ADME
– NO CEILING TO LIMITS OF CNS depression
• Adverse effects:
– Resp. depression, hypotension in toxic doses, can readily cause
death
• Precautions
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Highly addictive - physical dependence – withdrawal can be severe
Caution in elderly
Caution with other CNS agents
Caution with IM injection
Drug Abuse
Chapter 37
Terms
• Drug abuse
“using a drug in a fashion inconsistent with medical or social
norms”
• Addiction- you have to have it! You will not eat and steal from your
baby daddy to get your shiz…
• Cross-tolerance- if you take a lot of hydrocodone the morphine
might not do you much good. If you’re used to a drug, you might be
used to its drug cousin
• Psychological dependence- mentally addicted to
chocolate/marijunana
• Physical dependence- your body freakin needs it!
• Cross-dependence- if you are dependent on a drug, you are very
likely to become addicted to its drug cousin
• Withdrawal syndrome
Table 37-1 DSM-IV-TR Diagnostic Criteria for
Substance Abuse and Substance Dependence