CNS Flashcards
cognitive symptoms
difficulty w/ attention and applying information to make decisions
blood-brain barrier
- lipid drugs can pass
- water-soluble can’t pass very easily
- not fully present at birth
barbiturates safety concerns
- habit-forming
- low therapeutic index
- benzodiazepines are more commonly used because they are safer and more effective
barbiturates drug effects
dose-dependent!
- low: sedative
- high: hypnotic, lower RR
- enzyme inducer (metabolism of other drugs)
barbiturates increased metabolism of…
- C hloramphenicol
- WA rfarin
- S teroids
- T olbutamide & Theophylline
- G riseofulvin
(Cause WASTaGe)
Barbiturates SE
- A taxia
- B ehavioural disturbance
- C oma & decreased Concentration
- D epression, Drowsiness, Diplopia
(ABCD)
Barbiturates AE
- CV: vasodil, hypotn
- CNS: drowsiness, lethargy, vertigo
- Resp: depression, cough
- MS: ataxia
- GI: N/V, constipation
- Hem: thrombocytopenia, agranulocytosis
- Neuro: decreased REM
- SJS
Barbiturate Toxicity/OD
- resp depression/arrest
- CNS depression: coma/death
- treated symptomatically but not reversible (oxygenation, fluids, charcoal)
High (near toxic) doses of barbiturates used for
- induced coma
- anesthesia induction
- uncontrollable seizures
- must be in a controlled environment
OTC Hypnotics
- sleep aids contain antihistamines (CNS depressant)
- Doxylamine (unisom)
- Diphenhydramine (Sominex)
- Acetaminophen/Diphenhydramine (Extra Strength Tylenol PM
- ZQuil
- use w/ alcohol can be fatal (resp depress)
Benzodiazepines indications
- acute seizures
- alcohol withdrawal
- agitation
- moderate/conscious sedation
Benzos MOA
- depress CNS
- affect hypo/thalamicm limbic systems
- Benzo receptors (GABA)
- Don’t suppress REM as much
- Don’t increase metabolism of drugs
Benzos contraindications
- NA glaucoma
- pregnancy
Benzos AE
- HA
- drowsiness
- dizziness/vertigo
- cognitive impairment
- lethargy
- fall hazard (older pt)
- REM rebound
- hangover effect
(these are mild and infrequent)
Benzos toxicity/OD
- Somnolence (extremely tired)
- Confusion
- Coma
- decreased reflexes
- w/other CNS depressants: hypotn and resp depress
- symptomatic/supportive treatment
- antidote: Flumazenil
Classifications of stimulants
- Amphetamines (i.e. Adderall)
- Serotonin agonists (Sumatriptan for migraines)
- Sympathomimetics (stim adrenergic receptors)
- Xanthines (caffeine)
CNS stimulants therapeutic uses
- anti-ADD
- antinarcoleptic
- anorexiant
- antimigraine
Drugs for ADHD
- CNS stimulats b/c they increase NT like dopamine, serotonin, epi
- Amphetamines: methylphenidate (Ritalin) and dextroamphetamine (Adderall)
- Nonamphetamines: modafinil (Provigil)
Misc indications for antidepressants
- adjunct for schizophrenia
- eating disorders
- personality d/o
- migraines
- chronic pain/sleep d/o
- premenstrual syndrome (PMS)
- hot flashes (menopause)
types of antidepressants
- Monoamine oxidase inhibitor (MAOI)
- Selective Srotonin Reuptake Inhibitors (SSRI)
- Serotonin-norepi reuptake inhibitors (SNRI)
(others are SARI, NDRI, alpha2 adrenoreceptor antagonist)
Tricyclin Antidepressant
- TCAs
- second line (behind SSRIs)
- adjunct therapy with other antidepressants
- Amitriptyline
- Block reuptake of NT, so they accumulate
TCA AE
- sedation
- impotence
- ortho hypo
- in older pt: dizziness, constipation, delayed micturition, edema, muscle tremors
Antimania drugs
- mood stabiliziers
- Lithium was the 1st
- contraindicated in renal/CV dz, dehydration, Na depletion, diuretics (risk of toxicity)
- serum range of lithium 0.8-1.2
- lithium toxicity. (1.5)
Antipsychotics
- Haloperidol (Haldol) for Tourette’s and schizo
- Haldol contraindicated in Parkinson’s, dementia with Lewy bodies (d/t blocking of dopamine receptors)
- Risperidone (Risperdal) for schizo, acute manic episodes, and irritability in autism
Tardive Dyskinesia
- AE of antipsychotics
- involuntary contraction of oral and facial muscles
- wavelike movements of extremities
Neuroleptic Malignant Syndrome (NMS)
- AE of antipsychotics
- life-threatening
- high fever
- unstable BP
- myoglobinemia (myoglobin in blood)
Extrapyramidial symptoms
- AE of antipsychotics
- involuntary motor symptoms similar to in Parkinson’s
- akathisia (distressing motor restlessness)
- acute dystonia (painful muscle spasms)
- treated w/ anticholinergic meds (benzotropine and trihexyphenidyl)
GABA
- Gamma aminobutyric acid
- amino acid/NT in brain
- inhibitory
- reduce neuron excitability in NS
- some antiseizure drugs enhance this effect
- Gabapentin is anticonvulsant and treats nerve pain
Seizure
- episode of abnormal electrical activity in brain
Convulsion
- involuntary spasmodic contractions (any muscles in body)
Epilepsy
- chronic recurring pattern of seizures
Seizure disorder
- not always epilepsy
- may be caused by trauma, poisoning, fever, withdrawal, etc.
Status epilepticus
- multiple seizure with no recovery in between
- results in hypotension, brain damage, death
- can be caused by an abrupt discontinuation of anticonvulsants
Antiepileptics
- aka anticonvulsants
- control or prevent seizures
- minimize AE and drug induced toxicity
- lifelong therapy
- may be a combination of drugs
- serum must be measured
Serum concentrations of antiepileptics
- concentrations of phenytoin, phenobarbital, carbamazepine, levetiracetamm, primadone correlate with seizure control and toxicity
- concentrations of valproic acid, ethosuximide, and clonazepam do not correlate as well
Antiepileptic AE
- necessitate a med change
- long-term phenytoin may cause ginivial hyperplasia (skin grows over teeth), acne, hirsutism, Dilantin facies (skin thickens)