Neuropharmacology and Pain Anesthetics Flashcards
- Overview of brain
◦ BBB: protects the brain, impedes entry of drugs, NOT fully developed at birth
‣ To enter: must be lipid soluble, molecules cannot be too large
◦ Prolonged drug exposure (many drugs need to be given over time for effectiveness): increased therapeutic effects, decreased A/E (brain gets used to them and wears off), increased tolerance and physical dependence
◦ Beers criteria: lists meds that are inappropriate for older adults
FDA Pregnancy Risk Categories
See notability
- Drugs for Parkinson’s Disease
◦ Overview
‣ Progressive, no cure, neuronal degeneration begins years before S/S appear
* TRiPS: Tremors at rest, Rigidity, Postural instability, Slowed movements
* Tx goal: provide symptom relief
‣ Drug therapy: goal to restore balance between dopamine (too little) and acetylcholine (too much)
* Levodopa: dopamine replacement drug
- Drugs for Parkinson’s Disease
◦ **sinemet (levoDOPa / carbidopa) **
‣** levoDOPa**
* Class: dopamine replacement
* MOA: Converted to dopamine; 1st line drug
* For: 1st line tx, takes a few months to work
* Admin: always take levodopa with carbidopa or entacapone
* A/E: Dose Dependent, Dyskinesia, Dark urine and sweat (normal), Dysrhythmias, insomnia / nightmares
* Edu: Avoid high protein meals “LEVodopa = keep meals at LEVel”, LevoDDDDopa
* Drug interactions: 1st gen antipsychotics (dec effects of sinemet), MAOIs (inc toxicity)
‣ carbidopa
* MOA: dopamine agonist, inhibits deCARBoxylation of levodopa in body, increases effect of levodeopa so dose can be decreased ! => less levo A/E
◦ CARBidopa inhibits deCARBoxylation of levodopa
* Admin: Max dose 8 tabs, can wear off in between doses
* A/E: None, levodopa A/E d/t inc effect
* Edu: Avoid high protein meals
- Drugs for Parkinson’s Disease
◦ entacapone (Comtan)
‣ MOA: inhibits COMT which decreases metabolism of levodopa
* EntaCAPone puts a CAP ON metabolism to make it last longer => increases effectiveness of levodopa
‣ Admin: take with levodopa (no therapeutic effect by itself)
‣ A/E: N/V/D, constipation, yellow / orange discolored urine (normal!), increased levodopa A/E
- Drugs for Parkinson’s Disease
◦ pramipexole (Mirapex)
‣ MOA: activates dopamine receptors
‣ For: motor improvement, Restless Leg Syndrome; only drug used as monotherapy in early Parkinson’s (advanced w/ levodopa)
‣ A/E: nausea, dizziness, daytime somnolence (don’t drive during the day after starting drug), insomnia, constipation, weakness, hallucinations, increases compulsive behavior
‣ Contraindications: disorders with compulsive behaviors, renal impairment
‣ Ami is a ballet dancer (she has good motor skills), during the day she gets home from dance class and is soooo sleepy! Ami is compulsive
- Drugs for Parkinson’s Disease
◦ selegiline (Elderpryl, Zelapar)
‣ MOA: MAOI that deactivates dopamine
‣ For: improving motor dysfunction, may delay neurodegeneration, prolongs effects of levodopa
‣ Admin: **buccal route **(absorbed), avoid tyramine containing foods, avoid liquids with ODTs
‣ A/E: HTN crisis, buccal irritation (ODT), insomnia, orthostatic HoTN, dizziness, GI symptoms
‣ Drug interactions: meperidine, SSRIs
- Drugs for Alzheimer’s Disease
◦ Overview
‣ Loss of acetylcholine in advanced AD contributes to memory loss, low folic acid
‣ Goal of tx: slow progression of disease and prolong independence
* Use cholinesterase inhibitors and NMDA receptor antagonists (these take a few months to take effect)
- Drugs for Alzheimer’s Disease
◦ donepezil (Aricept)
‣ MOA: increases availability of acetylcholine (cholinesterase inhibitor)
‣ A/E: most serious - bronchoconstriction (asthma), bradycardia, sick sinus syndrome
‣ Edu: does NOT cure AD, but briefly delays progression (takes a few months to take effect); take med with food, stand up slowly
‣ Drug interactions: 1st gen antihistamines, 1st gen antipsychotics, tricyclic antidepressants
‣ DonePEZil => I would eat PEZ as a kid and they dispensers are so skinny (bronchoconstriction). Afterwards, I would lie down and sleep (bradycardia) “ZZZ” looks like SSS
- Drugs for Alzheimer’s Disease
◦** memantine (Namenda)**
‣ MOA: regulates Ca intake into cells, prevents toxic lvls (NMDA receptor antagonist)
‣ For: pts with moderate to severe symptoms
‣ Monitor: BUN / creatinine
‣ Caution: drugs that alkalize urine (ex. Na bicarb), hepatic or renal impairment
‣** MEMANtine: “me man” is a strong man (eat Ca for strong bones); Merman => water => kidneys**
Drugs for Epilepsy
◦ Overview
‣ Different drugs used for partial (does not spread far) or generalized (both hemispheres) seizures
* Valproic acid is effective for all types of seizures
‣ Drugs suppress discharge of neurons within the focus (seizure area) or suppress spread of seizure activity from the focus
‣ Tx goal: reduce or eliminate seizures as much as possible, trial and error is used for tx plan
‣ Edu: avoid driving and other hazardous activities, withdraw slowly, potential for suicidal ideation
‣ Monitor: plasma lvls to determine effectiveness; consider increasing the dose before changing drugs
‣ Pregnancy and epilepsy:
* Use lowest dose possible and monotherapy (uncontrolled seizures pose a greater threat than the meds do)
* 2 mg/day of folic acid; 10 mg Vit K daily during last few weeks of pregnancy, newborns 1 mg Vit K IM at birth
- Drugs for Epilepsy
◦ phenytoin (Dilantin)
‣ MOA: blocks Na entry into neurons
‣ For: partial or generalized tonic clonic seizures
‣ Admin: diluted and given slowly d/t possible K increase
‣ A/E: gingival hyperplasia (give folic acid, edu good oral hygiene / soft bristled toothbrushes), bleeding tendencies in newborns, dysrhythmias w/ HoTN, risk for suicide (w/ all anti-epileptic drugs), narrow therapeutic range (10-20), pregnancy category D
‣ PhenyTOin: Pheny’s toes are in (Na) the way (blocks Na entry into neurons; Pheny has 10 toes and 20 fingers and toes (10-20 drug lvl)
* Old drug => old people have gingival hyperplasia
- Drugs for Epilepsy
◦** carbamazepine (Tegretol)**
‣ MOA: suppresses high frequency neuronal discharge
‣ For: DOC partial tonic clonic seizures
‣ A/E: nystagmus, blurred vision, diplopia, vertigo, unsteadiness, bone marrow suppression (leukocytopenia, thrombocytopenia, anemia), causes water retention (X for HF pts) aka eyes, unsteadiness, bone marrow suppression
‣ Drug interactions: oral contraceptives, warfarin, phenytoin, phenobarbital, grapefruit juice
‣** CarbamazePINE: never mix with grapefruit or PINEapple juice
‣ In the MAZE, I got partically lost bc I was seeing double. I got unsteady and broke my bone (marrow)
- Drugs for Epilepsy
◦ valproic acid (Depakote / Depakene)
‣ MOA: suppresses high frequency neurons targeting Na channels, prevents Ca from entering Ca channels
‣ For: all seizure disorders, bipolar disorders, migraine HA
‣ Admin: take with food, take with folic acid, pt should be on birth control
‣ Monitor: liver function
‣ A/E: hepatotoxicity, pancreatitis, hyperammonemia, nausea
‣ Valproic ACID: take acid with food; while taking acid- check LFTs
- Drugs for Epilepsy
◦ phenobarbital
‣ MOA: binds to GABA receptors; anticonvulsant barbituate
‣ A/E: lethargy, rickets, osteomalacia, sedation, respiratory depression
‣ Edu: take at night d/t sedative effect
‣ PhenoBARBital: “Barbie” never goes outside and gets no Vit D (no Vit D => rickets, osteomalacia)
- Drugs for Epilepsy
◦** gabapentin (Neurontin)**
‣ MOA: enhances GABA
‣ For: partial seizures, neuropathic pain, fibromyalgia, post-menopausal hot flashes
‣ A/E: ataxia
‣ Contraindications: reduce dose in renal impairment (monitor BUN/creat)
- Drugs for Epilepsy
◦ levetiracetam (Keppra)
‣ MOA: unknown
‣ For: myoclonic, partial-onset, generalized tonic-clonic seizures
‣ A/E: drowsiness, weakness, suicide ideation
‣ Contraindications: reduce dose in renal impairment (monitor BUN/creat)
‣** LeveTIRacetam: TIR => tear => sad ; When I am sad, I am weak, drowsy, and suicidal
* Tear => water => kidney**
- Status epilepticus treatment
◦ Def: continuous tonic clonic seizure lasting 20-30 min
◦ 1st line tx (1st 5 min): lorazepam (Ativan) ; 2nd line: diazepam (Valium)
‣ Long term control: phenytoin
- Local anesthetics
◦ Overview
‣ Admin: topical or IM (by provider); quick onset, may have long duration
* Often given with epinephrine to dec blood flow
‣ Drugs are selective - all the nerves in that area are blocked
- Local anesthetics
** ◦ lidocaine**
‣ MOA: prevents Na from entering Na channel
‣ For: suppresses locally or by injection
‣ A/E: respiratory depression, bradycardia, heart block, decreased contractility, dysrhythmias, N/V, HA
‣** Lidocaine: L for Local anesthetic**
- General anesthetics
◦ Overview
‣ MOA: produces unconsciousness / lack of response to painful stimuli
‣ Admin: inhaled or IV
‣ Drugs used to improve its therapeutic effects and counteract A/E: benzodiazepines, opioids, alpha 2 adrenergic agonists, anticholinergics, neuromuscular blocking agents, anti-emetics
- General anesthetics
◦** propofol**
‣ MOA: releases GABA, results in CNS depression
‣ For: induction and maintenance of general anesthesia, sedation, good for short procedures, can be used for burn care
‣ A/E:** respiratory depression, bacterial infxn, propofol infusion syndrome**
‣ Monitoring: continuous cardiac monitoring, change vial Q6 hrs
- General anesthetics
◦ isoflurane (Forane)
‣ Admin: inhalation
‣ A/E: decreases blood flow to kidneys and urine output
- Opioid analgesics
◦ Overview
‣ MOA: activates mu receptors
‣ Admin: use for no longer than 3-7 days for acute pain; if they are not effective in 1st month- won’t be effective later on either
‣ Edu: about other pain meds and nonpharm therapies
