Transcript Anti-depressant meds (CC)

Mental Health Nursing:
Pharmacology-Antidepressants
C. Calzolari
2016
Antidepressants
Are used to treat mild to severe depression.
They are also used for “Off label” use.
Many people have to work with HCP and try
different antidepressants until they find the right
one for them.
Most people need to take an antidepressant for
6 weeks before they feel the full effect.
Antidepressants
Some side effects subside after a few weeks,
others only go away after the medication is
stopped.
Most antidepressants must be tapered off.
Instruct patients not to stop suddenly.
Any patient who experiences mania s/s, esp.
when starting on SSRIs, should contact MD.
May need to be evaluated for bipolar disorder.
Warning
The caregivers of children taking SSRIs
should monitor them for depression that is
getting worse and thoughts about suicide.
The caregiver or medical consenter should
immediately talk to the doctor if this
happens.
Antidepressants
Certain brain chemicals, called
neurotransmitters, are associated with
depression:
Serotonin
Norepinephrine
Dopamine
How do antidepressants work?
Most antidepressants inhibit the reabsorption
(reuptake) of neurotransmitters into nerve cells,
and block nerve cell receptors.
This provides more neurotransmitters to the
brain, which boosts mood.
They may also lower the nerve cell’s sensitivity
to glutamate, an amino acid, that excites and
overwhelms brain areas associated with anxiety
and depression.
Classifications of Antidepressants
 Monoamine oxidase inhibitors (MAOIs)
 Tricyclic antidepressants
 Tetracyclic antidepressants
 Selective serotonin reuptake inhibitors (SSRIs)
 Serotonin & norepinepherine reuptake inhibitors
(SNRIs)
 Norepinepherine & dopamine reuptake inhibitors
(NDRIs)
Monoamine oxidase inhibitors (MAOIs)
MAOIs are the first antidepressants to be
used, dating back to the 1950s.
How do they work? – they prevent the
enzyme monoamine oxidase from
metabolizing the 3 neurotransmitters
mentioned before.
As a result, more of the neurotransmitters
are available to the brain.
Monoamine oxidase inhibitors (MAOIs)
These MAOIs are approved by the FDA for
treatment of depression:
Nardil (phenelzine)
Parnate (tranylcypromine)
Marplan (isocarboxazid)
Emsam (selegiline) transdermal patch
Monoamine oxidase inhibitors (MAOIs)
Side effects:
 Drowsiness, constipation, nausea, diarrhea, GI
upset, fatigue, dry mouth, dizziness,
hypotension, orthostatic hypotension, decreased
urinary output, decreased sexual function, sleep
disturbances, muscle twitching, weight gain,
blurred vision, headache, restlessness,
trembling, increased diaphoresis.
Monoamine oxidase inhibitors (MAOIs)
Safety concerns: high risk
MAOIs are usually reserved for persons whose
depression doesn’t improve with other
medications.
MAOIs can cause dangerous interactions with
certain foods, beverages and medications.
Monoamine oxidase inhibitors (MAOIs)
 Foods/beverages that contain high levels of
tyramine are prohibited: cheeses, yeast, pickled
foods, chocolates, certain meats and fruits,
alcohol (even alcohol free beer).
 What can happen? High increase in blood
pressure
 Drug to drug interactions: other antidepressants,
antihypertensives, diabetes medicine, certain
pain medications such as Ultram & Demerol,
OTC decongestants, herbal weight loss products
and St. John’s Wort.
Tricyclic Antidepressants
They inhibit the reabsorption (reuptake) of
mainly serotonin & norepinepherine and
less so, dopamine.
These are some of the earliest
antidepressants.
Many side effects.
Tricyclic Antidepressants
Tricyclics approved by FDA for
treatment of depression:
Elavil (amitriptyline)
Asendin (amoxapine)
Norpramin (desipramine)
Sinequan (doxepin)
Tofranil (imipramine)
Vivactil (protriptyline)
Surmontil (trimipramine)
Pamelor (nortriptyline)
Tricyclic Antidepressants
Side effects: orthostatic hypotension,
drowsiness, dizziness, impaired sexual
function, disorientation, headache,
sensitivity to sunlight, weight gain, nausea,
weakness.
Anticholinergic effects: dry mouth, blurred
vision, constipation, urinary retention,
tachycardia
Tricyclic Antidepressants
Precautions: with DM, seizure HX or
thyroid problems, kidney disease, elderly.
Drug reactions with CNS depressants,
anticholinergics, MAOIs.
Contraindications: narrow-angle
glaucoma, BPH, certain heart diseases.
Tetracyclic Antidepressants
 They work a little differently. They work by
preventing neurotransmitters from binding with
certain nerve cell (alpha-2) receptors. This
indirectly increases the levels of serotonin and
norepinepherine in the brain.
 FDA aprroved tetracyclics: Remeron (mirtazapine)
 Side effects: drowsiness, weight gain, dry mouth,
dizziness, thirst, aches, constipation, increased
cholesterol.
 Safety concerns: rare s.e. – agranulocytosis. MD to
be notified in case of fever, sore throat, flu- like
symptoms.
Selective serotonin reuptake inhibitors
(SSRIs)
 Most commonly prescribed antidepressants.
 The first drug in this class was Prozac, in 1987.
 SSRIs affect serotonin levels in the brain.
 FDA approved SSRIs:
Celexa (citalopram)
Lexapro (escitalopram)
Prozac (fluoxetine)
Paxil (paroxetine)
Zoloft (sertraline)
Selective serotonin reuptake inhibitors
(SSRIs)
 Side effects: nausea, sexual dysfunction, dry
mouth, headache, diarrhea, nervousness, rash,
agitation, restlessness, diaphoresis, weight gain,
drowsiness, insomnia.
 Safety concerns: a rare but potentially lifethreatening s.e. – serotonin syndrome.
 Pregnancy – will discuss later in lecture
 Use of ASA, NSAIDS or Coumadin with SSRIs
increases risk of GIB.
Serotonin & Norepinepherine reuptake
inhibitors (SNRIs)
Increase serotonin & norepinepherine
levels in the brain.
FDA approved SNRIs:
Cymbalta (duloxetine)
Effexor (venlafaxine)
Serotonin & Norepinepherine reuptake
inhibitors (SNRIs)
 Side effects: nausea, vomiting, dizziness,
insomnia, sleepiness, abnormal dreams,
constipation, diaphoresis, dry mouth, yawning,
tremor, flatus, anxiety, agitation, abnormal vision,
headache, sexual dysfunction.
 Safety concerns: with high doses of Effexor,
hypertension may occur. Also raises cholesterol.
Avoid all SNRIs with glaucoma. Use of ASA,
NSAIDS, Coumadin may increase risk of GIB.
Norepinepherine & dopamine reuptake
inhibitors (NDRIs)
They increase the levels of both
norepinepherine & dopamine by inhibiting
their reabsorption into cells.
FDA approved NDRIs for depression:
Wellbutrin (bupropion)
Norepinepherine & dopamine reuptake
inhibitors (NDRIs)
 Side effects: loss of appetite, weight loss,
headache, dry mouth, rash, diaphoresis,
nervousness, stomach pain, agitation,
constipation, anxiety, dizziness, trouble sleeping,
muscle pain, nausea, fast HR, sore throat,
frequent urination.
 Safety concerns: may increase BP,
contraindicated with seizure HX ,TBI, eating
disorders. Can cause liver problems.
 Patient should not smoke.
Misc. Antidpressant
Trazadone is a trazolopyridine
antidepressant. Because of its sleep
inducing effects, it is more likely
prescribed as a sleep aide.
Safety concern: can cause priapism.
Related Topics
 Antidepressant Discontinuation Syndrome
 Serotonin Syndrome
 How to manage side effects
 Suicide with the use of antidepressants
 Use with children, teens and the elderly
 Off Label use
 Safety in pregnancy
 New research
Antidepressant Discontinuation
Syndrome
Occurs in appx. 20% of patients after
abrupt discontinuation of an
antidepressant drug that was taken for at
least 6 weeks.
S/S: flu-like symptoms, insomnia, nausea,
headache, nightmares, ataxia, dizziness,
blurred vision, numbness, anxiety,
agitation, psychosis with MAOIs.
Antidepressant Discontinuation
Syndrome
 Patients at Risk:
 Patients may be tempted to d/c medications after they begin to
feel better.
 Pregnant women.
How to prevent?
Tapering of the antidepressants is recommended
How to treat this syndrome?
It generally runs its course within 1-2 weeks. TX for trycyclics
may require anticholinergic drugs.
Serotonin Syndrome
 Characterized by very high levels of serotonin.
 Can occur when combinations of drugs that
affect serotonin are used.
 S/S:
Agitation, confusion, hallucinations, loss of coordination,
fast HR, changes in BP, fever, profuse diaphoresis,
hyperreflexes, nausea, vomiting, diarrhea, seizures,
coma.
Serotonin Syndrome
 Drugs that may cause Serotonin Syndrome are:
SSRIs
SNRIs
NDRIs
MAOIs
Pain medications – such as fentanyl, Demerol, Ultram
Anti-nausea medications – Zofran, Reglan
Migraine medications – Imitrex, Axert, etc.
OTC cough/cold medicines
Street drugs – Ectasy, LSD
Herbal supplements – ginseng, St. John’s Wort
Lithium
Serotonin Syndrome
Treatment:
Stop these drugs.
May require observation in hospital for
monitoring.
Should resolve in 24 hours.
Severe s/s will require more extensive TX in
hospital: muscle relaxants, serotonin-production
blocking agents, drugs that control heart rate
and BP.
How to Manage Common Side Effects
 Most people taking antidepressants will
experience at least one side effect.
 Many side effects subside after a few weeks.
Some remain as long as the drug is taken.
 Instruct your patient to notify MD if any side
effects become problematic.
 The most common side effects are: constipation
or diarrhea, drowsiness, dizziness, dry mouth,
headache, nausea, sexual dysfunction, tremors,
sleep disturbances, weight gain.
GI Disturbances
Constipation: increase po intake, high fiber
diet, more fruits and vegetables.
Nausea: discuss with MD and/or
pharmacist. Timing of administration may
help. Anti-nausea medications should be
avoided. Why?
Usually subsides within 30 days.
Diarrhea: may subside. If a problem, MD
may switch drug. BRAT diet if necessary.
Other Side Effects
 Dizziness: instruct patient to change positions
slowly, especially upon arising.
 Drowsiness: timing of administration may help.
Night time administration if OK with MD. May
subside over time.
 Insomnia: once again, timing of administration
may help. Give early in day.
 Sometimes, Trazadone is ordered for night to
induce sleep.
 Tremors: depending on severity, MD may have
to switch medication.
Other Side Effects
 Dry mouth: may subside with time. Hard candies
or gum may help. Frequent oral care.
 Headache: usually subsides with time.
 Weight gain: some drugs cause more weight
gain than others. Wellbutrin may actually cause
weight loss.
 Sexual dysfunction: major cause of
noncompliance. Wellbutrin is least likely to
cause this side effect. Prozac, Paxil & Zoloft
have highest rate of sexual s.e.
Risk of Suicide
In some instances, antidepressants have
been associated with worsening
symptoms of depression or suicidal
thoughts, especially in children, teens, and
young adults.
 Close monitoring at the beginning of
treatment and with any changes in
dosages is recommended.
Use With Children, Teens and the
Elderly
 Children: not many antidepressants have been approved for use with
children. Only Prozac is approved by the FDA for major depression.
Therefore, all other antidepressants are prescribed “Off Label”.
 Teens and Young Adults: must be monitored closely because of high risk
of suicide for this age group combined with increased risk associated
with the administration of antidepressants. See handout.
 Elderly: FDA recommends smallest effective total dose . Certain
antidepressants may be contraindicated with dementia. Also, many
elderly patients are on multiple medications, which increases risk of
adverse drug interactions. Also, medications may be metabolized more
slowly due to the aging process.
Off Label Use
 What does that mean?
 Doctors prescribe a medication to treat a disease that is different
than the disease(s) studied by federal regulators. Or they may
prescribe a drug that has not been studied by the FDA in certain
populations, such as children.
 In other words, off label use is not approved by the FDA.
 Many drugs used for off label use are antidepressants and
antipsychotics.
 Examples: Zoloft is approved for depression but is prescribed off
label for bipolar disorder.
 Implications?
 Safety and efficacy has not been formally studied.
 Insurance companies may not cover for off label prescriptions.
 So … why do doctors prescribe this way?
Safety with Pregnancy
There is a low risk of birth defects with
certain antidepressants. Many SSRIs,
Nardil and Parnate should be avoided as
per the Mayo Clinic.
If a woman is being treated for depression,
discussions with treating MD should be
discussed well in advance of pregnancy.
New Research
 Serotonin is one of several neurotransmitters
that brain cells use to communicate with each
other.
 Abnormalities are believed to be involved with
depression, bipolar disease, anxiety disorder,
autism and schizophrenia.
 Scientists are researching the chain of molecular
events that are involved with mental illnesses.
 They are finding that certain genes and
enzymes are involved as well. They are
experimenting on mice to block the enzyme and
to manipulate the affecting gene.