CNS Flashcards
Amphetamine based stimulants examples
Amphetamine (Adderal)
Methylphenidate (Ritalin)
What are the indications of amphetamines
ADHD
Narcolepsy
Mechanism of action of amphetamine
Stimulates CNS through a sympathomimetic mechanism involving the enhanced release and reduced reuptake of NE and Dopamine
Adverse effects of ampthetamines
Photosensitivity( due to mydriasis)
Visual disturbance (paralyze accommodation)
Elevated BP(release NE stimulate A1)
Infection (fight flight-increased steroid release)
Headache
Serious side effects=
Dependency and abuse
Psychosis
Growth suppression
Heart failure
Stevens-johnson syndrome
Drug interaction between amphetamines and CAI (carbonic anhydrase inhibitors) (Diamox)
Renal excretion of amphetamine is decreased in alkaline urine
Dug interaction between amphetamines and sympathomimetic drugs eg phenylephrine
Hypertensive crisis
Arrhythmia
Dug interaction between amphetamines and ophthalmic B-blockers
Hypertensive crisis
Contraindications of amphetamines
Glaucoma
ADHD results from low levels of
Dopamine
Depression results from low levels of
NE and serotonin
SSRI (selective serotonin reuptake inhibitors) examples
Escitalopram
Sertraline
Fluoxetine
Escitalopram (SSRI) indication
Major depression
Generalized anxiety disorder
Escitalopram (SSRI) adverse effects
Common:
- Dizziness
Distinguishing:
- suicidal risk
- serotonin syndrome(serious)
- Neuroleptic malignant syndrome
- Seizures
Ocular:
- dry eye
- Blur
- Diplopia
- Conjunctivitis
- Ptosis
Drug interactions with SSRI’s (Escitalopram)
NSAIDS & Omega 3- hemorrhage risk (diminishing platelet aggregation)
Ophthalmic B-Blockers- reduced B-blocker metabolism (CYP450)
SNRI (Serotonin norepinephrine reuptake inhibitors) examples
Duloxetine
Venlaflaxine
Indication of SNRI’s
Depression
Anxiety
Diabetic neuropathic pain
Fibromyalgia
Adverse effects of SNRI’s
Common:
Blurred vision
Headache
Dizziness
Sweating
Erectile dysfunction
Orthostatic hypotension
Hypertension
Syncope
Yawning
Constipation
Distinguishing:
Serotonin syndrome
Hypersensitivity: Angioedema, Stevens-Johnsons
Ocular:
Glaucoma
Drug interactions with SNRI’s
Opioids- additive effect- shut down digestion
NSAID & Omega 3 - hemorrhage
Beta-blocker- reduced B-Blocker metabolism
Cautions for use of SNRI’s
Risk of bleeding
Angle closure glaucoma
TCADs (tricyclic antidepressants) examples
Imipramine
Amitriptyline
Clomipramine
Indications of trazodone(atypical antidepressant)
Major Depressive disorder
Insomnia
Examples of atypical antidepressants
Trazodone Bupropion (wellbutrin, Zyban) Nefazadone
Mechanism of action of Trazodone (atypical antidepressant)
SSRI
A1 blocker
Seratonin 2a/c blocker (5-HT a/c)
Adverse effects of Trazodone (atypical antidepressant)
Common:
Headache
Dizziness
Blurred vision
Ocular irritation
Distinguishing:
Suicidal ideation
5-HT syndrome (serotonin syndrome)
CVS: hemorrhage
Drug interactions of Trazodone (Atypical antidepressant)
Cyclosporine, Macrolides(antibiotic),Azoles- QT prolongation & impaired hepatic metabolism
NSAID-hemorrhage
Mania is due to an excess of which neurotransmitters
NE, 5-HT and DA
Difference between D1 and D2 receptors
D1- stimulatory
D2- inhibitory
1st generation (typical) antipsychotics are antagonists of which receptor
Selective D2
2nd generation antipsychotics have selectivity for which receptors
Vary in selectivity for D2 and 5-HT2A- higher risk of metabolic side effects (hyperglycemia, dyslipidemia, weight gain)
3rd generation antipsychotic acts as functionally selective drugs. True or false
True
1st generation antipsychotic examples
Haloperidol
Chlorpromazine
Thiorodazine
2nd generation antipsychotic examples
Quetiapine
Clozapine
Olanzapine
Risperidone
Ziprasidone
Iloperiodone
What was the first ever antipsychotic
Lithium
3rd generation antipsychotic examples
Aripiprazole (partial agonist of D2 and 5HT1A)
Brexpiprazole (partial agonist of D2,D3 and near full agonist of 5HT1A)
Indications of Quetiapine( 2nd gen antipsychotics)
- Schizophrenia
- Bipolar
Adverse effects of quetiapine
Common:
- Headache
- Anemia
Hypersensitivity:
- Stevens-Johnsons
Muscular:
- Extrapyramidal symptoms
Ocular:
- Cataracts
Quetiapine (2nd gen antipsychotic) mechanism of action
Antagonizes D2 and 5HT2 receptors
Name a CNS drug which is associated with cataract formation
2nd gen antipsychotics eg Quetiapine
1st gen antipsychotics eg Haloperidol
Interactions with quetiapine(2nd gen antipsychotic)
Macrolides, Azoles, cyclosporine - Prolonged QT segment
Classic(sedating) antihistamines -additive CNS depression
1st gen antipsychotic side effects
Haloperidol:
- Photosensitivity
- Anticholinergic effects
- Drowsiness
- Anxiety
- Cataracts
- Retinopathy
Chlorpromazine&Thioridazine:
- Blur
- Ocular pigmentation
- Jaundice
- Photosentitivity
- Cataracts
- Retinopathy
- Night blindness
- Salt & pepper fundus
What drug is associated with salt and pepper fundus
Chlorpromazine/ Thioridazine
Adverse effects of lithium
Blurred vision
Seizures
Bradycardia
Idiopathic intracranial hypertension
Drug interactions with lithium
Caffeine and CAI - reduced lithium levels through diuresis
NSAIDs , tetracycline- increased lithium levels
Alzheimers
Loss of cholinergic neurons
Donepezil (Alzheimer therapy) indication
Alzheimer’s
Dementia
Mechanism of action of Donepezil (Alzheimer’s therapy)
Indirect acting, reversibly binds to and activates acetylcholinesterase (AChE) resulting in a sustained acetylcholine response
Adverse effects of Donepezil
- Headache
- Dizziness
- Arthritis
- Seizures
- Dream disturbances
- Hemolytic anemia
- AV block (atrioventricular block)
- Bradycardia
- Syncope
Drug interactions with Donepezil
- Cholinergic agents(pilocarpine) - additive
- NSAIDs- Hemorrhagic risk
- Anticholinergics(atropine)- Antagonism
- Macrolides& azoles- Reduced metabolism of donepezil
- Dexamethasone- Enhanced metabolism of donepezil
- Brimonidine & Timolol ophthalmic- Enhanced bradycardia and bronchospasm
- Ester Anesthetics- Reduced metabolism of anesthetics
Sinemet (Levodopa &Carbidopa) combination is indicated for
Parkinson’s
Mechanism of action of Sinemet(Levodopa and carbidopa)
Levodopa is a DA precursor that unlike DA crosses the BBB to enhance DA synthesis
Carbidopa is an inhibitor of dopa decarboxylase (enzyme that degrades levodopa to dopamine), peripheral degradation prevents drug crossing BBB
(makes sure the levodopa enters cns)
Adverse effects of sinemet(Levodopa&carbidopa)
Headache
Confusion
Psychosis(elevation of catecholamines)
Suicidal ideation
Hallucinations
Indications of Bromocriptine
Parkinson’s
Acromegaly (developemental condition)
Hyperprolactinemia
Neuroleptic malignant Syndromes(over activity in muscles)
Mechanism of action of Bromocriptine
Stimulates DA receptors
Inhibits anterior pituitary prolactin secretion
Adverse effects of Bromicriptine
Headache
Dizziness
Nasal congestion(changes in vascular tone)
Visual disturbance
Seizures
Neuroleptic malignant syndrome if abrupt discontinuing
Hypertension
Orthostatic hypotension
Drug interactions of Bromocriptine
Avoid:
Pseudoephedrine, epinephrine- additive hypertension
Monitor:
Cyclosporine(more oral)- levels of both drugs may rise
Caution:
Cetirizine -additive CNS depression
Macrolides, Azoles-elevated bromocriptine levels
Contraindications for bromocriptine
Uncontrolled hypertension (HTN)
Safinamide indications
Parkinson’s
Dystonia
Mechanism of action of Safinamide
Selectively inhibits MAOb
Increasing extracellular DA in the striatum
Adverse effects of Safinamide
HTN (hypertension)(elevate sympathetic activity)
Nausea
cough
Hallucinations
NMS (Neuroleptic malignant Syndrome) if abrupt discontinuation
Retinal degeneration(animal studies)
Contraindications of Safinamide
Tramadol(opioid) - additive 5HT-syndrome risk
Monitor: (additive HTN)
Caffeine,
epinephrine,
Naphazoline ophthalmic
oxymetazoline opt
phenylephrine oph
pseudoephedrine
Anxiolytics
Majority of drugs in this class promote actions of GABA which is the CNS major inhibitory neurotransmitter
________ is nr 1 stimulatory neurotransmitter
______ nr 1 inhibitory neurotransmitter in CNS
Glutamate is nr 1 stimulatory neurotransmitter in CNS
GABA is the nr 1 inhibitory neurotransmitter in CNS
Anxiolytic/hypnotic drug classes
Benzodiazepines
Non-benzodiazepines
Barbiturates
Intermediate acting Benzo’s
Alprazolam(low potency, high TI)
Lorazepam
Temazepam(low potency, igh TI)
Clonazepam(high potency and lower TI)
Short acting Benzo’s
Midazolam
Triazolam
Long acting benzo’s
Diazepam
Chlordiazepoxide(low potency, high TI)
Flurazepam
Indications of Alprazolam(Benzo)
Anxiety
Panic disorder
Mechanism of action of Alprazolam(Benzo)
Selectively binds to BZD(benzodiazepine) site on GABAa receptors, allosterically enhancing GABA affinity
Receptor activation opens ion channel leading to chloride influx or efflux and resultant hyperpolarization(inhibition)
Does cocaine, benzo’s, amphetamines act directly or indirectly on receptors
Indirect
Side effects of alprazolam(Benzo)
- Diplopia
- Drowsiness
- Anterograde amnesia
- Confusion
- Dizziness
- Hypotension
- Steven’s-Johnson
- Angioedema
Drug interactions of Alprazolam(Benzo)
Cyclosporine, Azoles, Macrolides - reduced alprazolam metabolism
Chlorpheniramine, diphenhydramine, opioids -additive effect
Contraindications of alprazolam(Benzo)
unstable Myasthenia gravis
Non-benzo example
Zolpidem
Indications of zolpidem
Insomnia
Mechanism of action of zolpidem(non-benzo)
Selective agonist of GABAa-BZD-1 receptor
Adverse effects of zolpidem
Headache
Sinusitis
Pharyngitis
Amnesia
Suicidal ideation
Aggression
Hallucinations
(Flippen verslawend! veronderstel om nie te wees)
Drug interactions with zolpidem
Cyclosporine, Azoles - reduced metabolism of zolpidem
Classic antihistamines, opioids- additive
Indications of phenobarbital(barbituate)
Seizure disorder
Status epilepticus
Sedation
Mechanism of action of phenobarbital(barbituate)
Convey synaptic inhibition to sensory cortex and to cerebellar and motor activities ,produces sedation, hypnosis and anesthesia
Enhances GABA effects at GABAa receptor
Adverse effects of phenobarbital
Drowsiness
Nausea and vomitting
Respiratory depression
Hypersensitivity: Steven’s-Johnsons, angioedema,
Blood dyscrasias
Withdrawal symptoms if abrupt discontinuation
Drug interactions of phenobarbital
- Acetaminophen(paracetamol)-phenobarbital enhances acetaminophen metabolism leading to metabolic toxicity risk
- Opioids-phenobarbital enhances acetaminophen metabolism leading to metabolic toxicity risk
- Erythromycins(macrolides), tetracyclines, steroids- enhanced metabolism by phenobarbital
- Azole antifungals- enhanced metabolism by phenobarbital
- Classic antihistamines- additive cns depression
- Lidocaine topical- increased methemoglobinemia risk
Contraindications of phenobarbital
Respiratory dysfunction
Indications of phenytoin
Seizure disorders
Status epilepticus
Mechanism of action of phenytoin
Modulates neuronal voltage-dependant sodium and calcium chanels
Adverse effects of phenytoin
- Nystagmus
- Blur
- Headache
- Pancytopenia (lower than normal red&white blood cells and platelets in blood)
- Hypersensitivity- stevens johnsons, TEN (rare life threatening skin condition)
- Lupus
Drug interactions with phenytoin
Acetaminophen- induced hepatic metabolism by phenytoin metabolite toxicity riak with repeated dosing
Erythromycin,azoles,opiods,steroids- induced hepatic metabolism by phenytoin
Antihistamines-additive cns depression
Topical lidocaine- increased methemoglobinemia risk
Acyclovir- reduced phenytoin levels
Contraindications of phenytoin
Caution in diabetes
Examples of muscle relaxants
Cyclobenzaprine
Tizanidine
Indication of cyclobenzaprine and tizanidine
Muscle spasm
Fibromyalgia
Mechanism of action of cyclobenzaprine
Central acting: potentiates NE and stimulates serotonin receptors
Mechanism of action of tizanidine
Central acting: binds to presynaptic alpha 2 adrenergic receptors, inhibits neurotransmitter release
Adverse effects of cyclobenzaprine symptoms
Blur
Headache
Hypersensitivity
Myocardial infarction
Adverse effects of tizanidine
Hypotension
Blur
Syncope
Bradycardia
Hypersensitivity stevens johnsons
Drug interactions of cyclobenzaprine
Avoid anticholinergics- additive effects
Avoid serotonergic agents - additive effects, risk of serotonin syndrome
Drug interactions of tizanidine
Ciprofloxacin- reduces tizanidine metabolism leading to a rise in levels with routine dosing
Adverse effects of cyclobenzaprine
Blur
Headache
Hypersensitivity
Myocardial infarction
Adverse effects of tizanidine
Hypotension
Blur
Syncope
Bradycardia
Hypersensitivity stevens johnsons
Drug interactions with cyclobenzaprine
Avoid Anticholinergics- additive effects
Avoid serotogenic agents- additive effects, riak of serotonin syndrome
Contraindications of cyclobenzaprine
CNS depressant use
Narrow angles
Elevated IOP
Contraindications of tizanidine
CNS depressant use
ADHD is characterized by low/high levels of which neurotransmitter
Low dopamine
Depression is characterized by low/high levels of which neurotransmitters
Low Norepinephrine and low serotonin
Mania/psychosis is characterized by low/high levels of which neurotransmitters
High Dopamine, high Norepinephrine and high Serotonin
Alzheimers is characterized by low/high levels of which neurotransmitters
Low Acetylcholine and high Glutamine
Parkinsons is characterized by low/high levels of which neurotransmitters
Low Dopamine , high Acetylcholine
Anxiety is characterized by low/high levels of which neurotransmitter
Low GABA