Pharm Exam 2 1
CNS Pharmacology
Nearly all drugs with CNS effects act on specific receptors that modulate synaptic transmission
Neurotransmitters
o Epinephrine
fight or flight
o Norepinephrine
concentration (levels of activity, alertness, appetite, sleep patterns)
o Dopamine
pleasure (sleep, sexual behavior, anxiety/agitation, euphoria, addictions)
o Serotonin
mood (anxiety, sexual behavior, appetite, aggression, pain, obsessions, emesis, learning, psychosis, migraine, sleep,
suicidal ideation)
o GABA
calming
o Acetylcholine
learning & memory
o Glutamate
memory
o Endorphins
euphoria
CNS Drugs
o -bital barbiturate (sedative) butobarbital, phenobarbital, secobarbital
o -pramine tricyclic antidepressant (TCA) clomipramine, desipramine, imipramine
o -triptyline TCA amitriptyline, nortriptyline
o -ridone atypical antipsychotic iloperidone, risperidone, paliperidone
o -azepam benzodiazepine clonazepam, diazepam, lorazepam
o -zolam benzodiazepine alprazolam, midazolam, triazolam
o zodone antidepressant nefazodone, trazodone, vilazodone
o -ine antidepressant fluoxetine, sertraline, SSRIs
o -triptan migraines sumatriptan, naratriptan, almotriptan
Anticonvulsants
Block transmission and raise seizure threshold
Require a certain therapeutic level to work consistently; frequent blood work
Drug level, CBC (Tegretol can cause agranulocytosis), TSH (meds can affect the thyroid)
Take on regular basis at the same time every day
Patient safety—driving limitations, heavy machinery operation, etc.
Increase need for oral care
Topiramate (Topamax)
Monitor serum bicarb can cause low serum bicarb = hyperchloremic metabolic acidosis
MOA: Blocks NA channel; potentiates GABA
Levetiracetam (Keppra)
Do not abruptly discontinue
MOA: binds to protein SV2A
Safer in pregnancy
Carbamazepine (Tegretol)
CBC every 3 months
Risk for agranulocytosis, anemia
MOA: blocks Na+ channels
,Pharm Exam 2 2
Valproate (Depakote)
Do not take while pregnant
MOA: increase GABA in the brain by blocking reuptake
Drug MOA Side Effects Monitoring Pt. Teaching
Topiramate (Topamax) Block Na+ channel; Ocular syndrome ↓serum bicarb. (hyper- Inform of eye problems
potentiates GABA Oligohydramnios, chloremic met.acidosis
hyperthermia
Carbamazepine Block Na+ channel Agranulocytosis, CBC, (WBC, RBC, Plts) Do NOT stop abruptly
(Tegretol) anemia
Stevens Johnson Synd.
, Pharm Exam 2 3
Valproate Increase GABA in brain GI distress, heartburn, Pregnancy X
(Depakote) by blocking its uptake CNS depressant
in presynaptic neurons
Levetiracetam (Keppra) Binds to protein SV2A ↑suicidal thoughts, Suicide Safer in children and
Does not affect GABA depression, Withdrawal seizures if pregnancy
behavior/mood stopped abruptly
changes
Questions:
Henry has recently started on carbamazepine to treat seizures. He comes to see you and you note that while his carbamazepine levels
had been in the therapeutic range, they are now low. The possible cause for the low carbamazepine levels include:
Carbamazepine auto-induces metabolism, leading to lower levels despite good compliance.
Carbamazepine has a Black Box Warning due to life-threatening:
Dermatologic reaction, including Steven’s Johnson and toxic epidermal necrolysis
Long-term monitoring of patients who are taking carbamazepine includes:
Complete blood counts every 3 to 4 months (can be a decrease in WBC & platelets)
Six-year-old Felisha has recently been started on ethosuximide (Zarontin) for seizures. She should be monitored for:
Blood dyscrasias, which are uncommon but possible
What should families be taught regarding seizure activity monitoring?
Prevention of seizures, patient safety, quality of life issues, reach acceptable goals for treatment, & do not abruptly stop taking seizure
meds
What electrolyte imbalance is associated with topiramate?
Decreased sodium bicarb leading to hyperchloremic metabolic acidosis
Lisa, who is overweight, recently started taking topiramate for seizures and at her follow-up visit you note she has lost 4 kg. The
appropriate action would be:
Reassure her that this is a normal side effect of topiramate and continue to monitor her weight.
Travis’s seizures are well controlled on topiramate and he wants to start playing baseball. Education for Travis regarding his topiramate
includes:
He should monitor his temperature and ability to sweat in the heat while playing
Brandy is taking valproate (Depakote) for seizures and would like to get pregnant. What advice would you give her?
Valproate is a known teratogen, but may be taken after the first trimester if necessary. Keppra is a better drug to be on until the
second trimester, then she can go back to valproate.
What category is valproate?
Category X
Antidepressants
Neurotransmitters involved in depression
o Serotonin
influences anxiety, sexual behavior, appetite, aggression, pain, obsessions, emesis, learning, psychosis, migraine,
sleep, suicidal ideation
o Norepinephrine
influences level of activity, alertness, appetite, sleep patterns