CNS drugs

Question 1

CNS review

Answer 1

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.

Question 2

factors that may precipitate seizures

Answer 2

sleep deprivation, high caffeine, hyperventilation, stress, hormonal changes, sensory stimuli, drug/alc, infections, fever, metabolic disorders

Question 3

hydantoins anticonvulsants -pharmacokinetics and drug interactions

Answer 3

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

Question 4

anorexiants use

Answer 4

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.

Question 5

lamotrigine/Lamictal drug/drug

Answer 5

levels decreased by barbiturates, ESTROGENS, phenytoin, Mefloquine. levels increased by ETOH, carbabazepine, CNS depressants, valproic acid

Question 6

dopaminergics - drugs available

Answer 6

amantadine/Symmetrel, bromocriptine/Parlodel, levodopa (L-Dopa, Larodopa), carbidopa-levodopa/Sinemet, pramipexole/Mirapex, ropinirole/Requip

Question 7

anorexitants available

Answer 7

diethylproprion (Tenuate, Tenuate Dospan cat 4), phendimeetrazine Tartate, orlistat (Xenical, Alli is OTC) non-CNS lipase inhibitor, phentermine/Adepex-P, sibutramine/Meridia (cat 4)

Question 8

anorexiants precautions, ADRs, considerations, contras

Answer 8

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

Question 9

how antiseizure drugs act

Answer 9

stimulating influx of chloride ions, usually associated with GABA. delaying infux of sodium, calcium.

Question 10

lamotrigine/Lamictal ADRs

Answer 10

GI (mostly n/v, constipation); CV (CP, peripheral edema); CNS (somnolence, fatigue, dizzy, anxiety, insomnia, HA, amblyopia, nystagmus; rashes

Question 11

anorexiants action and PK

Answer 11

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.

Question 12

hydantoins (type of anticonvulsant) available

Answer 12

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)

Question 13

anticonvulsants: succinimides - uses, drugs available, pharmacodynamics, PK

Answer 13

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

Question 14

hydantoin anticonvulsants - use and pharmacodynamices

Answer 14

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

Question 15

anorexiants drug/drug

Answer 15

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”

Question 16

lamotrigine/Lamictal patient ed

Answer 16

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)

Question 17

hydantoins anticonvulsants - ADRs

Answer 17

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)

Question 18

anticonvulsants: carbazepine/Tegretol/Tegretol XR/Carbatrol, oxcarbazepine/Trileptal, valproic acid/Depakote/Depakene pharmacodynamics and pharmacokinetics precautions

Answer 18

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

Question 19

drug interactions: imonostilbenes (includes carmazepine)

Answer 19

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

Question 20

hydantoins - monitoring and pt ed

Answer 20

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

Question 21

dopaminergics - PK, ed, PD, monitoring

Answer 21

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.

Question 22

stimulant class II drugs available

Answer 22

amphetamine (methyphenidate, dexamphetamine, amphetamine). non-amphetamine: atomoxetine/Strattera

Question 23

ADRs: imonostilbenes (includes carmazepine)

Answer 23

bone marrow depression, liver damage, impaired thyroid fxn, drowsy, dizzy, blurred vision, n/v, dry mouth, diplopia, HA

Question 24

anticonvulsants: succinimides - ADRs

Answer 24

GI most common; CNS (ataxia, somnolence, fatigue); agranulocytosis, aplastic anemia, granulocytopenia

Question 25

monitoring and patient ed: imonostilbenes (includes carmazepine)

Answer 25

baseline CBC, chem panel, hepatic panel, TSH level. ed: teach s/s of bone marrow suppression, CAREFUL use of medications, KINDLING

Question 26

opiods

Answer 26

morphine is prototype, all opiods rated against it. single agent products (oxycodone, morphine); combo products (Vicodin, Percocet, Percodan, Tylenol with Codeine). Bind to opiod receptors in CNS. PK vary. ADRs: CNS depression, constipation, euphoria

Question 27

dopaminergics - uses and action

Answer 27

Restores DA in areas of the brain. attempt to restore functional balance of dopamine and acetylcholine in corpus stratium of brain. treatment of choice for parkinsons disease

Question 28

lamotrigine/Lamictal - uses, PK

Answer 28

adjunctive treatmetn of primary generalized clonic-tonic seizures and partial seizures adults/kids 2y+. Concurrent use with valproic acid, phenytoin. Met in liver and kidneys