Week 10 (drugs of abuse and CNS) Flashcards
Differences between Pramipexole, Ropinrole, and Rotigotine
Pramipexole is used w/ mild PD, or w/ levodopa in severe PD
Side effects are more common with Ropinrole, but less common when combined with L-dopa
Mechanism of action for Rotigotine is not known, probably in the substantia nigra (not D2 and D3 receptor binding like the other ones)
Another name for Non ergot alkaloids
dopamine agonists
Contraindications for non ergot alkaloids
if N/V occurs can’t give with seratonin antagonists like zofran (orthostatic hypotension) or dopamine receptor antagonists (opposite effects)
AE of apomorphine
Injection site rxns (no PO dosing) hallucinations,
drowsiness,
dyskinesia,
N/V.
4% serious CV events
Difference between Selegiline and Rasagline
Metabolites of Selegiline are amphetamine and methamphetamine, so they can cause CNS excitation and insomnia
Rasagiline may increase risk for malignant hyperthermia, assess skin
What is amantadine used for?
helps manage dyskinesias with L-dopa
rapid response that decreases within 3-6 mo
What is the benefit of entacapone with L-dopa
It helps L-dopa reach the brain so it can work, also causing less peripheral side effects d/t conversion to dopamine
How do dopamine agonists work and what are they used for
Dopamine agonists (ergot alkaloids and non ergot alkaloids) work by direct agonism of dopamine receptors in striatum. They are used for PD
When giving any medications that suppress immune responses, what are points of patient education? (hint: re: illness, infection, vaccines)
Before starting treatment, patients should become up to date on vaccines, since once the immune system is suppressed, it will be hard for the immune system to create new antibodies, and person will need increased immunity because they have less of an ability to fight infections
Once treatments are started the person is considered immunocompromised, so they should avoid sick people and encourage loved ones to get vaccinated to prevent giving them illnesses
Avoid concurrent administration of multiple immunosuppressants
These meds can also be very expensive, and are sometimes not covered by insurance
What is benzotropine used for
PD, as a second line drug for tremor
it is less effective than L-dopa or dopamine agonists but is better tolerated
AE of benzotropine
CNS (sedation, confusion, hallucinations)
peripheral: anticholonergic effects
What is Mitoxantrone used for and how does it work?
mitoxantrone is used as a immunosuppressant to slow the progression of MS, it works by inhibiting DNA repair and synthesis (decreased immune cell proliferation/activation, decreased myelin destruction)
List the three MAJOR adverse effects of mitoxantrone.
Myelosuppression (neutropenia, anemia, thrombocytopenia)
Irreversible cardiotoxicity, can occur years after drug has been stopped
Fetal injury (even in low doses, r/o pregnancy before each dose)
Knowing that Na+ channel receptors have 3 states (open, inactivated, and closed) how do these types of antiseizure drugs prevent neuronal transmission on some neurons, but not all neurons?
Slows progression from inactive to closed, so action potential only in hyperactive neurons are suppressed
Discuss PK variances of antiseizure medications
Phenobarbital – CYP450 inducer
carbamazepine – CYP 450 inducer, is metabolized by CYP450
Oxycarbemazepine – Induces CYP450, can increase metabolism of oral contraceptives
Lamotrigine – estrogen lowers drug levels
topiramate w/ phenytoin – lowered drug levels of both
tiagabine – metabolized by CYP 450
What is ethosuximide used for?
Absence seizures
AE of Oxcarbazepine
CNS depression
Hyponatremia
Hypothyroidism
Skin rxns and hypersensitivity
nursing considerations for oxcarbazepine
avoid alc and other hypo Na+ drugs
contraindications for valproate
CNS depression and bad drug toxicity when combined with other anti-seizure meds
pregnancy
AE of bupropion
dry mouth, insomnia, HA, rare seizure risk,
Contraindications of bupropion
contraindicated with MAOI use, avoid in those with seizures
How does memantine work?
regulates glutamate at NMDA receptors causing more normal Ca2+ influx (in neuron that still work)
What are Beta-a drugs (endogenous inteferon B) used for? What do they do?
these immunomodulators are used in MS to modify immune responses (including B and T cells)
cautions with interferon beta
antibody stimulation against the drug itself can occur, rxns can range from mild to anaphylaxis
They also require special handling, esp for pregnant RNs
What is dalfampridine used for and how does it work?
dalfampridine is used for gait issues in MS (improves walking speed). It is a k+ channel blocker, but the mechanism is a little unclear
Mechanism of action of lamotrigine
Na+ channel inactivation (mostly) and Ca2+ channel blocker
Unusual AE of lamotrigine
more SI
Mechanism of action of pregabalin
binds Ca2+ presynaptically, inhibits glutamate, NE, and substance P
Unusual AE of pregabalin
hypersensitivity rxns
Euphoria (thus a controlled substance)
decreased fertility
Unusual AE of levetiracetam
maybe renal injurry
Mechanism of action of topiramate
GABA potentiation,
Na+ and Ca2+ block,
glutamate receptor block
Mechanism of action of tiagabine
decreased GABA reuptake
Unusual PK of tiagabine
metabolized by CYP450
Unusual AE of topiramate
metabolic acidosis is a risk,
higher SI maybe
Unusual PK of topiramate
w/ phenytoin, altered drug lvls of both
AE of baclofen
(minimal)
CNS depression. OD –> coma, resp depression
GI = N/V, constipation, urinary retention
w/d symptoms occur (hallucinations, paranoia, seizures)
CI of baclofen
other CNS depressants (avoid EtOH)
urinary retention (BPH, anticholinergics)
Psych conditions (may be exacerbated)
AE of dantrolene
reduction in strength/weakness
hepatic toxicity (1:1000)
drowsiness
diarrhea
CI of dantrolene
caution w/ calcium channel blockers (bc of both decreased influx and efflux of Ca2+, could case HF
AE of cyclobenzaprine
CNS depression (subsides w/ use)
similar structure to TCAs –> anticholinergic effects, cardiac rhythm changes
AE of naltrexone
Nausea
HA
dizziness
sedation
AE of varenicline
Nausea (decreases w/ time)
HA
sleep disturbances
constipation
dry mouth
flatulence
altered sense of taste
Mechanism, effects and PK of Marijuana
mechanism: activation of cannabinoid receptors
Effects: pleasure, memory, thinking, concentration, appetite, sensory and time perception
PK: CYP450 inhibitor
Approved uses of marijuana
supression of emisis (esp in CA chemo)
appetite stimulation in AIDS
Tx of sz in Lennox-Gastuat and Davet syndrome
Relief of neuropathic pain in MS (not approved in the US yet)
