Pharm Flashcards
What ↑ risk of LAST?
- Hypercarbia (↑ CBF → more drug → brain)
- Hyperkalemia (↑ RMP)
- Metabolic acidosis
Max dose lidocaine for tumescent
55mg/kg
Max dose chlorprocaine
Plain chlorprocaine: 11mg/kg, 800mg total
With epi: 14mg/kg, 1000mg total
What is clearance directly proportional to? Inversely proportional to?
Clearance is directly proportional to:
→ blood flow to clearing organ
→ extraction ratio
→ drug dose
Clearance is inversely proportional to:
→ half-life
→ drug [] in central compartment
Longest context-sensitive half times of opioids
Fentanyl (by a mile)
Alfentanil
Sufentanil
Remi is flat -
How to tell if a drug is a weak acid or base by its name
A weak acid is paired with a + ion such as sodium, calcium, Mg
→ Sodium thiopental
A weak base is paired with a (-) ion such as chloride or sulfate
→ Lidocaine hydrochloride
→ Morphine sulfate
Etc etc
→ of ↓ plasma proteins
Liver disease, renal disease, old age, malnutrition, pregnancy, neonates
Zero order kinetic drugs
ETOH, ASA, phenytoin, Warfarin, heparin, theophylline
Drugs who undergo perfusion dependent hepatic elimination
Fentanyl Lidocaine Propofol Sufentanil Ketamine Bupivicaine Metoprolol Propranolol
HBF greatly exceeds enzymatic activity
Drugs that undergo capacity-dependent hepatic elimination
Roc Diazepam Lorazepam TPL Phenytoin
Changes in hepatic enzyme activity or protein binding have profound effects on these drugs (ER <0.3)
Differences in drug excretion with basic and acidic urine
Basic urine favors
→ reabsorption of basic drugs
→ excretion of acidic drugs
Acidic urine favors
→ reabsorption of acidic drugs
→ excretion of basic drugs
Drugs eliminated by nonspecific esterases
Remi, esmolol, etomidate (partially), atracurium (partially)
Therapeutic index
LD50/ED50
LD50=lethal in 50% population
ED50=effect in 50% population
Racemic mixtures
Ketamine, morphine, iso, des, bupivicaine, methohexital, TPL, methadone, toradol
Protein binding numbers for IV anesthetics
Propofol 98%
Midaz, precedex 94%
Etomidate 75%
Ketamine 12%
Which opioid is naloxone not that effective in reversing?
Buprenorphine. Binds to the mu receptor with an affinity 50x greater than morphine. It’s also v slow to dissociate from the receptor. For these reasons, it is highly resistant to competitive antagonism by Narcan.
Things that prolong the half life of drugs dependent on hepatic metabolism
-↓ drug delivery to liver
→ CHF
- ↓ hepatic metabolism
→ cirrhosis
What do pKA, lipid solubility, and protein binding correlate to in terms of LAs?
PKA → onset
Lipid solubility → potency
Protein binding → DOA
Drugs that can mess with pseudocholinesterase
Neostigmine Echothiopate Metoclopramide Esmolol BCP/estrogen Cyclophosphamide
Things that ↑ FA/FI → faster onset of inhaled agent
↓ uptake: low solubility of agent (think des)
↓ CO (hypothyroidism)
↑ Wash in: High FGF, High Aleveolar ventilation, low FRC, Low Vd
Things that decrease FA/FI → slow down onset of inhaled agent
↑ UPTAKE
↑ solubility (think iso) ↑ CO ↑ Pa-Pv difference
Vessel rich group
75% CO, 10% body mass
Muscle and skin
20% CO, 50% body mass