15 Pharmacology Flashcards
Drug agonist vs antagonist
Agonist- mimics naturally occurring substance to stimulate a specific receptor
Antagonist- binds to a receptor without activating it to block other potential substances from activating it
Therapeutic index
Toxic dose in 50% of subjects divided by effective dose in 50% of subjects
Higher numbers is safer
Enteral route of administration
Oral
Sublingual
Buccal
Rectal
Parenteral route of administration
Intravenous Intramuscular Transdermal Intrathecal Epidural
Topical route of administration
Creams
Ear/eye drops
Nasal sprays
Inhalers
Drug clearance
Volume of plasma from which a drug is eliminated per unit time
Half life
Time required to reduce plasma drug concentration by 50%
Usually takes 5 to be eliminated
Patients with decreased metabolism will have…
Decreased clearance
Increased half life
Increased plasma concentration
Most CNS medications…
Modify synaptic transmission
Anti-psychotics action
Inhibit dopamine transmission
First generation anti-psychotics
Chlorpromazine
Haloperidol
Perphenazine
Fluphenazine
Second generation anti-psychotics treat…
Both depressive and manic states
Adverse effects of anti-psychotics
Rigidity, tremors, muscle spasms Long-term use = tardive dyskinesia Orthostatic hypotension Change in weight, glucose levels, lipid levels (second generation) Dizziness
Types of sedatives/hypnotics
Benzodiazepines
Non-benzodiazepines
Dexmedetomidine (Precedex)
Benzodiazepines
Treat anxiety, seizures, spasticity, anesthesia
Binds to GABA receptors- inhibit neuronal firing
End in -am
Estazolam
Flurazepam
Quazepam
Clonazepam
Barbituates
Non-benzodiazepines Promote sleep, general anesthetic Bind to GABA receptors Highly addictive, small TI End in -al Amobarbital Phenobarbital Pentobarbital
Non-benzodiazepine meds
Bind to GABA to decrease arousal and increase sleepiness Shorter duration and half-life Zaleplon (Sonata) Zolpidem (Ambien) Eszopiclone (Lunesta)
Dexmedetomidine (Precedex)
Sedative in ICU to control anxiety, agitation
Binds to alpha-2 receptor to decrease sympathetic response
May cause bradycardia or hypotension
Most common causes of epilepsy
Teens and adults- head trauma
Over 65 y/o- CVD
Partial seizure, simple
Focal areas of brain
Motor, sensory, autonomic, or psychological symptoms without obvious change in consciousness
Partial seizure, complex
Focal seizure activity with impaired consciousness
Generalized seizure, simple
Both hemispheres
Brief LOC without any other clinical signs
Generalized seizure, complex
LOC with notable clinical signs
Generalized seizure, absence
Brief lapses without loss of postural control
Generalized seizure, tonic-clonic
LOC with violent muscle contractions
Unclassified seizures
Usually in immature brains
First-line meds for partial seizures
Carbamazepine (Tegretol)
Phenytoin (Dilantin)
Oxcarbazepine (Trileptal)
Valproic acid (Valproate)
First-line meds for generalized tonic-clonic seizures
Valproic acid (Valproate)
Lamotrigine (Lamictal)
Topiramate (Topamax)
Seizure meds action and side effects
Blockage of voltage-gated sodium channels Nausea Dizziness Poor coordination Drowsiness/sleepiness Diplopia
Other meds for seizures
Calcium channel blockade
Increases GABA concentrations in brain
Neurostimulant actions
Increase synaptic concentration of dopamine, serotonin, and noradrenaline in various areas of brain
Increases neuronal sprouting and synpatogenesis
Increase synaptic efficiency by facilitating long-term potentiation
Neurostimulant meds
Methylphenidate (Ritalin)
Amphetamines
Dopamine agonists
Spasticity pros
Prevent muscle atrophy
Decrease edema
Prevents DVT
Decreases osteoporosis
Spasticity cons
Interferes with functional mobility
Painful spasms
Impairs sleep
Causes fractures or pressure injuries
Tizanidine
Centrally acting alpha-2-adrenergic agonist, decreases polysnaptic reflex activity
Used in marked muscle weakness
Side effects- hypotension, elevated liver enzymes, sedation, hallucinations
Baclofen
Acts centrally, binds to GABA receptors and inhibits spinal reflexes
Used when muscle weakness not severe
Side effects- sedation, muscle weakness, confusion, dyskinesia, hallucinations
Diazepam
Centrally acting, inhibits GABA receptors and pre/post-synaptic reflexes
Is a benzodiazepine
Used with painful night spasms
Side effects- sedation, habituation
Dantroline sodium
Acts on skeletal muscle, prevents release of calcium from sarcoplasmic reticulum
Severe spasms and spinal cord lesions
Side effects- weakness, diarrhea, hepatotoxicity
Clonidine
Decreases polysynaptic reflex activity
Used with spasticity associated with uncontrolled HTN
Side effects- orthostatic hypotension
Gabapentin
Similar structure to GABA, mechanism unknown
Used in MS and SCI
Side effects- sedation, confusion, fatigue, weight gain
Intrathecal baclofen
Lower doses with decreased side effects
Side effects- orthostatic hypotension, CSF leakage, sedation, loss of penile erection, local infection, pump malfunction
Botox injection
Acts on neuromuscular junction by inhibiting release of acetylcholine at pre-synaptic terminal
Results for 2-6 months
Meds for vestibular impairment
Sedatives- meclizine (Antivert)
Anti-emetics- ondansetron (Zofran)
Benzodiazepine- Diazepam (Valium)
MS relapse/exacerbation meds
Corticosteroids (IV or oral) to decrease inflammatory response
MS disease-modifying meds
Down-regulates immune response
Mimics myelin proteins to attract immune system and suppress response
Inhibits inflammatory cells
Alters lymphocytes in lymph nodes
Parkinson’s disease meds
Levodopa/Carbidopa (Sinemet)- gold standard Dopamine agonists COMT inhibitors MAO type-B inhibitors Anticholinergics Amantadine
Huntington’s disease meds
Tetrabenazine- suppresses chorea
Other meds that treat PD, epilepsy, panic/psychotic disorders to assist with managing abnormal movements
ALS meds
Riluzole- only approved med
Risks of long-term corticosteroid use
Increased infection risk Muscle weakness Eye problems Falls risk Osteoporosis
