Chapter 18
lecture 5
Chapter 18
Anticonvulsants
Anticonvulsants
• Epilepsy
* A seizure disorder occurring in about 1% of pop.
* Abnormal electric discharges from cerebral neurons
* Loss or disturbance of consciousness & convulsions
(Abnormal motor rxn)
* 50% = primary or idiopathic (cause unknown)
* 50% secondary to trauma, brain anoxia, infection
* Isolated seizures = febrile, hypoglycemic rxn,
electrolyte imbalance (hyponatremia), ETOH & drug
withdrawal
Anticonvulsants
• Classification of seizures
> Generalized - convulsive & nonconvulsive - both
cerebral hemispheres of the brain effected
- Tonic - clonic = grand mal - most common
Tonic = skeletal muscles contract or tighten in a spasm
Clonic = dysrhythmic muscular contraction: jerkiness
- Absence Seizures = petit mal - brief loss of
consciousness
> Partial - One hemisphere of brain. No loss of
consciousness in simple, loss in complex partial
Anticonvulsants
• Action of Anticonvulsants
> Drugs depress abnormal neuronal discharges,
therefore inhibiting seizure activity and
increase the seizure threshold (stabilizes
neuronal membranes.
> Inhibits excitatory nerve impulses; enhances
inhibitory nerve impulses.
Anticonvulsants
• Use - many different types of seizures, but not
all drugs used for all types of seizures
• Side Effects - Not the safest group of drugs;
many very serious side effects: teratogenic =
effects the fetus
• Narrow therapeutic index
• Usually taken throughout a persons lifetime compliance issues
Anticonvulsants
Hydantoins
• Phenytoin (Dilantin) - since 1938
* Least toxic, nonaddicting, sm. sedating effect
* Dosage varies according to age
* Narrow therapeutic index = monitoring serum drug
levels a must
* Highly protein bound
Drug-drug interactions
* Action - Reduces motor cortex activity by altering
transport of ions inhibits spread of seizure activity
* Uses - Grand mal & complex partial seizures
Anticonvulsants
Phenytoin (Dilantin)
• Side effects - Gingival Hyperplasia = overgrowth
of the gums - good oral hygiene a must!
* Long term use may elevate blood sugars
• Drug Interactions - Lots!!
Anticonvulsants
Barbiturates
• Phenobarbital - long acting
* Use - grand mal seizures & acute episode of of
status epilepticus (rapid succession of seizures)
* Action - Increases seizure threshold in motor
cortex
* SE - General sedation & client tolerance
Anticonvulsants
Miscellaneous Agents
• Carbamazepine (Tegretol) * Use - Grand mal, psychomotor, mixed seizures, &
when other anticonvulsants do not work
* Action - Unknown - Thought to work in Na ions
during generation of nerve impulses
* SE - Aplastic anemia (abnormal regeneration of
RBC’s), agranulocytosis (great in leukocytes
an increase risk of infection
Anticonvulsants
Miscellaneous Agents
• Valproic Acid (Depakote) * Use - Petit mal, grand mal, & mixed type of
seizures
* Action - Unclear - Probably increases brain
levels of GABA which transmits inhibitory nerve
impulses in the CNS
* SE - Hepatotoxicity, esp. in young children
* DI - Lots !!
Chapter 19
Antipsychotics, Anxiolytics, and
Antidepressants
Antipsychotics
• Used to treat symptoms of mental disorders
• Also known as neuroleptics & psychotropics
• Neuroleptic = any drug that modifies plychotic behavior,
thus exerting antipsychotic effect
• Psychosis = symptomatic in a variety of mental or
psychiatric disorders
- Characterized by more than one symptom - diff. in
processing info., delusions, hallucinations, incoherence,
catatonia, aggressive or violent behavior
Antipsychotics
• Schizophrenia - Chronic, major category of psychosis
- Usually occurs in adolescence or early adulhood
- Positive Symptoms = agitation, incoherent speech,
hallucination, delusion, & paranoia
- Negative Symptoms = or loss in function &
motivation, poverty of speech content, poor self-care,
social withdrawl - more chronic & persistent
* Traditional (typical) antipsychotics more helpful for
managing poss. symptoms than neg.
* A new group (atypical) more useful in treating both pos.
& neg. symptoms of schizophrenia
Antipsychotics
•
•
•
•
Comprise the largest group of drugs to treat mental illness
improve the thought processes & behavior
Not used for treating anxiety & depression
Theory - psychotic symptoms result from an imbalance of
the neruotransmitter dopamine in the brain (these drugs
sometimes called dopamine agonists)
• Antipsychotics block D2 dopamine receptors in the brain =
a dec. in psychotic symptoms.
• Many block the chemoreceptor trigger zone in the brain =
antiemetic effect
Antipsychotics
• Side Effects - Pseudoparkinsonism = a major side effect
of typical antipsychotic drugs
- Extrapyramidal symptoms (EPS) - mask-like faces,
rigidity, tremors, pill-rolling
* With high doses of drugs symptoms are more
pronounced
- Acute dystonia - muscle spasms of face, tongue, neck &
back - treat with anticholinergics (Cogentin)
- akathisia - trouble standing still, pacing, constant motion treat with benzodiazepines or beta blockers
- Tardive dyskinesia - serious with long term use of drug protrusion/rolling of tongue, sucking/smacking of lips,
chewing motion - best to D/C the drug
Antipsychotics
Phenothiazines
• Three groups: Aliphatic, Piperazine, & Piperidine - differ
mostly in their side effects
• Most of the antipsychotics can be given orally, IM, or IV
• Chlorpromazine (Thorazine) - First drug - aliphatic
- Action - alt. in DA effect on CNS
- Use - psychosis, Hiccups,
- SE - sedation, EPS,
- Adverse rxns - Hypotension, tachycardia ( pulse rate),
tardive dyskinesia, seizures
Antipaychotics
Phenothiazines
• Prochlorperazine (Compazine) - piperazine - low sedative
- Use - antiemetic
- Action - Acts on chemoreceptor trigger zone to inhibit
N&V
- SE - EPS symptoms, orthostatic hypotension
• Thioridazine (Mellaril) - piperidine - strong sedative
- Use - Psychosis
- Action - Unknown - probably blocks postsynaptic DA
receptors in the brain
- SE - Low incidence of EPS
Antipsychotics
Nonphenothiazines
• Haloperidol (Haldol) - a potent antipsychotic drug whose
dose is smaller than less potent drugs - Similar to
phenothiazines in pharmacologic action
- Action - Alters the effects of dopamine by blocking
dopamine receptors
- Use - Psychoses, Tourette’s syndrome
- SE - EPS symptoms, photosensitivity, hypotension
- CI - Glaucoma, severe hepatic, renal & CV disease
Antipsychotics
Atypical
•
•
•
•
New category since early 1900’s
Treats pos & neg symptoms of schizophrenia
Not likely to cause EPS or tardive dyskinesia
clozapine (Clozaril), risperidone (Risperdal), olanzapine
(Zyprexa) & quetiapine (Seroquel)
• Clozapine - can cause aggranulocytosis dec. in body’s
defense mechanism & seizures - used for severely ill only
• Risperdal, Zyprexa & Seroquel - Do not cause
aggranulocytosis, similar action to Clozaril
Anxiolytics or
Antianxiety Drugs
• Primarily used for treating anxiety and insomnia
• Major group = benzodiazepines - a minor tranquilizer
group
• More effective than barbiturates - enhance action of
GABA within the CNS, have fewer side effects, less
dangerous in overdosing - Wide therapeutic index
• Used when anxiety is excessive & could be disabling
• These agents treat the symptoms - not the cause
• Long term use discouraged - tolerance can occur
• Nonpharmacologic measures should be tried first, before
giving anxiolytics
Anxiolytics
Benzodiazepines
• Multiple uses: anticonvulsants, antihypertensives,
sedative-hypnotics, pre -op drugs & anxiolytics
• Used mainly for severe or prolonged anxiety, panic
attacks, phobias, compulsions ( not day to day stress)
• 3 frequently used = diazepam (Valium), alprazolam
(Xanax), & lorazepam (Ativan)
• Highly protein bound & could displace other highly
protein bound drugs
• Controlled substances - class IV
• Avoid ETOH
an in CNS depression
Anxiolytics
Benzodiazepines
• Diazepam (Valium) - Action - acts on limbic & subcortical levels of CNS
- Use - control anxiety, pre-op, muscle relaxant, ETOH
withdrawl, anticonvulsant
- SE - Drowsiness, orthostatic hypotension, confusion
- CI - Pregnancy - Potential to cause fetal birth defects
- Alert - Do not D/C abruptly = withdrawl symptoms
• Buspirone hydrochloride (BuSpar) - newest anxiolytic
- Action - ?? - may inhibit neuronal firing, serotonin
- Use - short-term relief of anxiety. 1-2 weeks for relief
- SE - < benzodiazepines, but still monitor CNS
Antidepressants
• Depression is the most common psychiatric problem,
about 10 - 20% of pop. affected
• Def. - mood changes & loss of interest in normal
activities, occurs every day for at least 2 weeks, interferes
with daily functioning. Symptoms: loss if interest in most
activities, weight loss or gain, insomnia or hypersomnia,
loss of energy, fatigue, feelings of dispair, suicidal
thoughts.
• Cause - Genetic, social & environmental factors, change
in neurotransmitter (NT) levels - norep. and/or serotonin
in the brain
Antidepressants
• Action - Antidepressants work to normalize NT balance
• Classes of drugs include:
- Tricyclic antidepressants (TCAs) or tricyclics
- Selective serotonin reuptake inhibitors (SSRIs) &
atypical antidepressants
- Monoamine oxidase (MAO)
• Most drugs need to be taken for 2-4 weeks for full effect
• Treatment should continue for 9 months after remission
of 1st episode; 5 yrs after 2nd; indefinitely after 3rd
Antidepressant Agents
Tricyclic Antidepressants
• Amitriptyline (Elavil)
*Action - Serotonin & Norep. increased in nerve
cells
*Use - Depression & anxiety
* SE - Sedation, drowsiness, anticholinergic effects
(dry mouth, urinary retention, constipation), EPS,
orthostatic hypotension
Antidepressant Agents
Selective serotonin Reuptake inhibitors
(SSRI)
• Action - not well defined - blocks reuptake of serotonin
into the nerve terminal of the CNS
• Do not block uptake of dopamine or norep.
• Do not block cholinergic receptors
• More commonly used to treat depression D/T fewer side
effects - but more costly
• Use - major depressive disorders, anxiety disorders, panic
attacks, phobias,
• 4 SSRI’s since 1988: fluoxetine (Prozac), fluvoxamine
(Luvox), sertraline (Zoloft), paroxetine (Paxil)
Antidepressants
SSRI’s
• Fluoxetine (Prozac) - most commonly prescribed
*Action - ?? - Thought to inhibit reuptake of
seretonin
* Use - Depression, obsessive-compulsive
disorders, bulimia
* SE - agitation, nervousness, insomnia, wt. loss
* DI - Lots!!1
* Onset of effect between 1 and 4 weeks
* Some clients experience sexual dysfuction
Antidepressants
Monoamine Oxidase Inhibitors
• Monoamine oxidase (MAO) - an enzyme normally inactivates norep., dopamine, epi. &
serotonin. By inhibiting = rise in these NT’s
• 2 forms of MAO - A & B
- MAO -A inactivates DA in the brain
- MAO -B inactivates norep. & serotonit
• MAOI’s are nonselective = inhibits both A & B
• Inhibition is thought to relieve symptoms of
depression
Antidepressants
MAOI’s
• 3 MAOI’s currently prescribed: tranylcypromine
sulfate (Parnate), phenelzine sulfate (Nardil),
isocarboxazid (Marplan)
• As effective as TCA’s for treating depression, but
D/T side effect of hypertensive crisis resulting
from food & drug interactions, only 1% of clients
use - tyramine rich foods & CNS stimulants can
cause the crisis
Bipolar disorder
Lithium
• Used mostly for the manic phase of manic-depressive
illness - has a calming effect without impairing
intellectual activity
• Increases receptor sensitivity to serotonin
• Has a narrow therapeutic index - monitor biweekly until
theraputic level reached then monitor monthly
- monitor sodium levels since lithium tends to dec. Na
• SE - dry mouth, thirst, increase urination, weight gain
• May have teratogenic effects on fetus
• Depakote is now being used to treat bipolar disorder