6 - CNS Drugs Flashcards
Acetaminophen
- MOA
- clinical indications
- adverse effects
Not understood
Analgesia, antipyresis (fever)
Safe for all ages, incl infants
Safe during pregnancy
Hepatotoxicity
Cyclobenzaprine
- MOA
- clinical indications
- adverse effects
Decr somatic (voluntary) motor activity by inhibiting tonic activity of alpha and gamma motor neurons
Treat muscle spasms
Drowsiness, loss of coordination, anticholinergic (dry eye, mydriasis, incr IOP) = caution in narrow angles
Tramadol
- MOA
- clinical indications
- adverse effects
1) agonist at Mu receptor
2) inhibit serotonin + NE uptake within asceding pain pathways
More potent analgesic than acetaminophen (but less than opiates)
Dry mouth, sedation, dizziness, nausea
Miosis: less frequently than true opiates
Meperidine, Oxycodone
- MOA
- clinical indications
- adverse effects
Agonist at Mu, Kappa, Delta opiate receptors
Potent analgesic, addictive properties
Miosis (pinpoint pupils, mydriasis with withdrawal)
Respiratory depression, drowsiness, sedation, nausea (reduced with promethazine)
Mep: excessive doses can result in build-up of normeperidine, a metabolite than can cause seizures, incr ICP, papilledema
List
- non-opiate analgesics (3)
- opiate analgesics (2)
NO: acetaminophen, cyclobenzaprine, tramadol
O: meperidine, oxycodone
Sumatriptan
- MOA
- clinical indications
- adverse effects
5HT1B and 1D receptor agonist (serotonin subtype 1B + 1D) -> vasoconstriction and reduced inflammation in CNS
Migraine
All SE are related to systemic vasoconstriction: NAION, MI, ischemic stroke, retinal artery occlusions/venous thromboses
Phenothiazines: Chlorpromazine, Thioridazine
- MOA
- clinical indications
- adverse effects
DA receptor antagonist
Antipsychotics
High doses can result in Parkinson-like effects
Ocular:
-pigment effects: corneal endo, anterior stellate ct, RPE hyperpig
-anticholinergic (dry eye, mydriasis, incr in IOP)
-oculogyric crisis (also cetirizine)
List
- antipsychotics (2)
- antiparkinsons (2)
- ADHD meds
Pysch: chlorpromazine, thioridazine
-decr DA
Park: amantadine, bromocriptine
-incr DA
ADHD: methylphenidate, dextroamphetamine
-incr DA
Amantadine
- MOA
- clinical indications
Potentiates DA effects by blocking reuptake or augmenting release in brain
Parkinson’s
Bromocriptine
- MOA
- clinical indications
- adverse effects
DA agonist
Prolactin-secreting pituitary adenomas
Parkinson’s
Parkinson’s characteristics
Due to DA deficiency
TRAP: Tremor at rest Rigidity (cogwheel) Akinesia loss of Postural reflexes (balance probs)
Methylphenidate, Dextroamphetamine
- MOA
- clinical indications
- adverse effects
Incr release of DA
ADHD, narcolepsy, depression
High dose chronic tx -> mydriasis, dry eyes
Caution in narrow angles: mydriasis may lead to acute or subacute angle closure
Donepezil
- MOA
- clinical indications
- adverse effects
CNS ACHase inhibitor
Alzheimer’s dementia
Ocular: cataracts, blurred vision, ocular irritation
- lowers IOP due to effects as an indirect cholinergic/muscarinic agonist
- sudden discontinuation of therapy may lead to incr IOP
Characteristics of antidepressants
4 classes: TCA, MAOI, SSRI, SNRI
-all incr serotonin concentrations
TCAs, MAOIs, and SNRIs also incr norepi
SE: fatigue/sedation, weight gain, sexual dysfunction
List
- SSRIs (2)
- SNRIs (2)
- TCAs (2)
- MAOIs (1)
SS: fluoxetine, excitalopram
SN: venlaxafine, duloxetine
TCA: amitriptyline, imipramine
MAOI: phenelzine
Fluoxetine, Excitalopram
- MOA
- clinical indications
- adverse effects
Inhibits serotonin reuptake (SSRIs)
Depression
Fewer SE than other classes
Ocular: mydriasis, caution with narrow angles
Serotonin syndrome may occur if RXd with MAOIs or TCAs
Serotonin syndrome
Due to excess serotonin activity in CNS
Change in mental status (anxiety, confusion), autonomic hyperactivity (incr BP, pulse, temp), neuromuscular problems (tremor, hyperreflexia)
Venlafaxine, Duloxetine
- MOA
- clinical indications
- adverse effects
Inhibits serotonin and norepi reuptake (SNRIs)
Depression, generalized anxiety disorder, panic disorder, social anxiety disorder
Risk of suicide, serotonin syndrome
Caution in pts with narrow angles or ACG: mydriasis
Drug and MOA for depression and smoking cessation
Buproprion
NDRI: inhibits reuptake of DA and NE
Amitriptyline, Imipramine
- MOA
- clinical indications
- adverse effects
Inhibits NE and serotonin reuptake (TCAs)
Depression
Anticholinergic effects (dry eye, incr IOP, mydriasis) Overdose is life-threatening, don’t rx to suicidal pt
Phenelzine
- MOA
- clinical indications
- adverse effects
Inhibits MAO: enzyme responsible for breaking down NE and serotonin
Depression
Ocular: -glaucoma, nystagmus -caution in narrow angles Systemic: -several interactions with other drugs/chemicals, foods with tyramine (wine, cheese, dried meats) -> lethal hypertensive crisis
Additional SE of MAOIs and TCAs
Exacerbate systemic effects of topical ophthalmic phenyl (10%) and other adrenergic agonists
Diazepam
- MOA
- clinical indications
- adverse effects
Benzodiazepine that opens Cl- channels by binding to GABA receptors -> hyperpol of neurons in CNS
Acute anxiety, panic attacks, sedative/alcohol withdrawal
-decr SNS
Sedation, depression, bradycardia, dyspnea - fatal if combined with alcohol
Ocular: mydriasis (paradoxical), nystagmus
-contraindicated in narrow angle glaucoma
Phenytoin
- MOA
- clinical indications
- adverse effects
Acts on multiple NTMs, incl NE, ACh, GABA
Anticonvulsants
Nystagmus, diplopia, EOM palsies, ataxia, gingival hyperplasia
