CNS drugs Flashcards
drugs not primarily used for anx/dep/bipolar/psychosis
CNS review
brain, spinal cord, retina. contains majority of nervous system. coordinates activity of all parts of body. brain and spinal cord serve as main processing center for entire nervous system and control all workings of body. millions of neurons provide capacity to reason, experience feelings, and understand the world. Neurons provide capacity to remember numerous pieces of information.
factors that may precipitate seizures
sleep deprivation, high caffeine, hyperventilation, stress, hormonal changes, sensory stimuli, drug/alc, infections, fever, metabolic disorders
hydantoins anticonvulsants -pharmacokinetics and drug interactions
met in liver: strong CYP2C9 effects. Levels will increase with cimetidine, diazepam, acute alcohol intake, valproic acid, allopurinol. Decreases effects with barbiturates, antacids, calcium, chronic alcohol use. If use with following drugs, will decrease the effects of the other drugs: carbamazepine, estrogens, tylenol, corticosteroids, levodopa, sulfonylureas, cardiac glycosides
anorexiants use
chose population carefully! Indicated for morbid exogenous obesity. all have potential to produce serious SEs. Rx drugs approved if BMI 30+, or 27+ if obesity related condition (HTN, DM2, dyslipidemia). short term use 8-12 weeks.
lamotrigine/Lamictal drug/drug
levels decreased by barbiturates, ESTROGENS, phenytoin, Mefloquine. levels increased by ETOH, carbabazepine, CNS depressants, valproic acid
dopaminergics - drugs available
amantadine/Symmetrel, bromocriptine/Parlodel, levodopa (L-Dopa, Larodopa), carbidopa-levodopa/Sinemet, pramipexole/Mirapex, ropinirole/Requip
anorexitants available
diethylproprion (Tenuate, Tenuate Dospan cat 4), phendimeetrazine Tartate, orlistat (Xenical, Alli is OTC) non-CNS lipase inhibitor, phentermine/Adepex-P, sibutramine/Meridia (cat 4)
anorexiants precautions, ADRs, considerations, contras
high risk for tolerance, dependence. avoid if alc/drug dependence hx. contra: abuse cocaine, meth, etc. ADRs: CNS overstimulation (agitation, confusion, isomnia, dizzy, HTN, HA, palp, arrhythmias, dry mouth, n/v) , sudden withdrawal of med in pts with long hx of use may experience withdrawal symptoms. increased glucose uptake of skeletal muscles, caution with DM. Avoid with hx of CV disease, drug history, DM difficult to monitor
how antiseizure drugs act
stimulating influx of chloride ions, usually associated with GABA. delaying infux of sodium, calcium.
lamotrigine/Lamictal ADRs
GI (mostly n/v, constipation); CV (CP, peripheral edema); CNS (somnolence, fatigue, dizzy, anxiety, insomnia, HA, amblyopia, nystagmus; rashes
anorexiants action and PK
chemically, pharmacologically r/t amphetamines. mode of action: thought to stimulate release of NE and/or DA from storage sites in nerve terminals in the lateral hypothalamic feeding center, thus decreasing appetite. Lipid soluble, wide distribution, cross blood-brain barrier. met by liver, excreted kidneys. DOA 4-6h.
hydantoins (type of anticonvulsant) available
ethotoin/Peganone (only avail 250mg), fosphenytoin/Cerebyx (NOT for primary care, only IM/IV, given only about 5 days), phenytoin/Dilantin (50mg chewable, oral suspension 100mg/4mL and 125mg/5mL 30mg cap, 100mg cap, ER 100mg cap)
anticonvulsants: succinimides - uses, drugs available, pharmacodynamics, PK
treatment of absence seizures in kids and adults. Ethosuzamide/Zarontin, methsuximide/Celontin. Supress seizures by delaying calcium influx into neurons. Decrease nerve impulses and transmission in motor cortex. absorbed GI tract, met in liver
hydantoin anticonvulsants - use and pharmacodynamices
NP role: work with neurologist who has made dx. Used for grand maul seizures and psychomotor seizures.
first line for clonic-tonic and partial complex seizures. works by stabilizing neuronal membrane and decreasing seizure activity by increasing efflux or decreasing efflux of sodium ions across cell membranes in motor cortex. onset, duration varies
anorexiants drug/drug
careful with serotonergic meds (increased risk for serotonin syndrome). Avoid MAOIs (hypertensive crisis). Careful use with adrenergic blockers, insulin sulfonylureas, phenothiazines. Lithium - toxicity of lithium. Orlistat decreases levels of levothyroxine, increases levels of warfarin. Off label use with SSRI: prozac and phenermine “Phen-Pro”
lamotrigine/Lamictal patient ed
adherence, avoid alcohol, avoid OTC meds, adequate hydration, report any new drugs, report ADRs, discuss risk factors that contribute to seizures, DRIVING, controversy if d/c med after a few years w/o seizures (neurologist needs to make decision)
hydantoins anticonvulsants - ADRs
many! Never give IM or IV in PC. Watch patients with liver or kidney disease closely. Most common: nystagmus, dizzy, pruritis, paresthesia, HA, somnolence effects, confusion; CV effects (hypotension, tachycardia); GI effects (n/v, anorexia, constipation, dry mouth, gingival hyperplasia; GU effects (urinary retention, urine discoloration)
anticonvulsants: carbazepine/Tegretol/Tegretol XR/Carbatrol, oxcarbazepine/Trileptal, valproic acid/Depakote/Depakene pharmacodynamics and pharmacokinetics precautions
depress neuron transmission in nucleus ventralis anterior of thalamus. Has ability to induce its own metabolism. Genetic testing of Asians. Black Box for blood dyscrasias. absorbed stomach, met liver, induces met of many CYP450 substrates
drug interactions: imonostilbenes (includes carmazepine)
watch out for GRAPEFRUIT juice. drug levels increase with concurrent use of propoxyphene/Darvocet, cimetidine, erythromycin, clarithromycin, verapamil, hydantoins. decrease plasma levels of several drugs: BB, warfarin, doxycycline, succinimiedes, haldol
hydantoins - monitoring and pt ed
baseline labs and plasma levels, TSH. Need to assess OTC drugs (ibuprofen, antacids). Ed: risk factors for seizures, report ADRs, avoid driving if not seizure free >1y, oral hygeine
dopaminergics - PK, ed, PD, monitoring
may take up to 6mos to achieve max therapeutic effects. PK varies with each drug. Many drug/drug. Monitor hepatic panels. ed: avoid abrupt d/c, avoid antacids, TCAs decrease effects, it may increase effects of HTN drugs.
stimulant class II drugs available
amphetamine (methyphenidate, dexamphetamine, amphetamine). non-amphetamine: atomoxetine/Strattera
ADRs: imonostilbenes (includes carmazepine)
bone marrow depression, liver damage, impaired thyroid fxn, drowsy, dizzy, blurred vision, n/v, dry mouth, diplopia, HA
anticonvulsants: succinimides - ADRs
GI most common; CNS (ataxia, somnolence, fatigue); agranulocytosis, aplastic anemia, granulocytopenia
