General Flashcards
Permissive drug
1) Allows other drugs to reach their full capacity
2) Cortisol for norepinephrine (cortisol increases alpha 1 receptors)
Decreased drug responsiveness with repeated administration
Tachyphylaxis
Combination of two drugs that creates an effect that is equal to the sum of the effects from the individual drugs
Additive
Combination of two drugs that creates an effect greater than the sum of the individual drugs effects
Synergistic
Drug used for cyanide poisoning?
1) Amyl nitrite
2) Thiosulfate
Drug used for iron poisoning?
1) Deferoxamine (chelating agent)
Drug used for arsenic poisoning? What does arsenic inhibit?
1) Dimercaprol
2) Lipoic acid (results in Pyruvate dehydrogenase and alpha ketoglutarate impairment)
How many drug half lives does it take for it to be completely removed from the system?
1) 4-5 half lives
How do you calculate a half life?
t1/2 = (V x .7)/Clearance
Study of drug effects and their mechanism of action; “What drugs do to you”
Pharmacodynamics
Quantitative descriptions of the time course of drug and drug metabolite; “What the body does to the drug”
Pharmacokinetics
What is inversely related to the affinity of an enzyme to its substrate?
Km
- Low Km = High affinity (seen in hexokinase)
What does a high Km mean?
Low affinity for substrate
Proportional to enzyme concentration
Vmax
What are the x and y axis on a lineweaver burk plot
1) X axis = 1/S(concentration substrate)
2) y axis = 1/V
As the y intercept increases on the lieweaver burk plot what happens to Vmax
1) Vmax decreases
Inhibitor that resembles the substrate, binds to the active site, increases Km (decreases affinity)
Competitive inhibitor
How can a competitive inhibitor be overcome?
Increase the substrate
Inhibitor that does not resemble the substrate, does not bind to the active site, decreases the Vmax
Non-competitive inhibitor
Fraction of administered drug that reaches the systemic circulation unchanged
Bioavailability (F)
What is the bioavailablility of an IV drug
100% (all of it reaches the systemic circulation unchanged)
How do you calculate volume of distribution
V = amount of drug in body divided by plasma drug concentration
What order of elimination are half lives only applicable to?
1) First order elimination
How do you calculate Clearance of a drug?
Cl = rate of elimination divided plasma concentration
How do you calculate a loading dose?
Loading dose = Cp x (Vd/F)
- Cp = target plasma concentration
- F = bioavailability
How do you calculate maintenance dose?
Maintenance dose = Cp x CL/F
Elimination rate that is constant regardless of target plasma concentration; Decreases linear with time
Zero order elimination
What drugs have zero order elimination?
Think: PEA (pea is round, shaped like the 0 in zero order)
1) Phenytoin
2) Ethanol
3) Aspirin (at high or toxic concentration)
Elimination rate that is directly proportional to concentration of drug
First order elimination
What determines whether a drug is reabsorbed or excreted in the urine?
1) If the drug is in its neutral form
How do you ensure a weak acid is excreted in the urine? weak base?
1) Make the urine basic (give bicarb) so that it remains in its ionized form
2) Make the urine acidic (give ammonium chloride) so that it becomes ionized
What phase of drug metabolism includes reduction, oxidation, and hydrolysis with P-450
Phase I
what is the result of phase I drug metabolism?
Production of water-soluble metabolites
What phase of drug metabolism is lost as we grow older
Phase I
What phase of drug metabolism includes conjugation yielding very polar, inactive metabolites
Phase II
Maximal effect a drug can produce
Efficacy
Amount of drug needed for a given effect
Potency
What changes potency
Competitive inhibitor
What changes efficacy
Noncomeptive inhibitor
What inhibitor cannot be overcome by the addition of more substrate?
Noncompetitive inhibitor
What is the effect of a partial agonist?
1) Decreases efficacy and changes potency
Median lethal dose/ median effective dose
Therapeutic index
Think: TILED
Therapeutic index = Lethal dose/Effective dose
Treatment for acetaminophen overdose
N-acetylcysteine (replenishes glutathione)
Treatment for salicylate overdose
NaHCO3 (alkalinize urine), dialysis
Treatment for amphetamines overdose
NH4Cl (acidify urine)
Treatment for Acetylcholine esterase inhibitors overdose/poisoning
1) Atropine
2) Pralidoxime (regenerates acetylcholine esterase)
Treatment for Antimuscarinic agents overdose
1) Physostigimine
Treatment for beta blocker overdose
1) Glucagon
Treatment for digitalis overdose
Think: KLAM
1) normalize K
2) Lidocaine
3) Anti-dig Fab fragments
4) Mg
Treatment for Lead intoxication
1) CaEDTA
2) Dimercaprol
3) Penicillamine
Treatment for Mercury/Arsenic/Gold intoxication
1) Dimercaprol
2) Succimer
Treatment for Copper/Arsenic/Gold intoxication
1) Penicillamine
Treatment for Methemoglobin intoxication
1) METHylene blue
Treatment for carbon monoxide poisoning
1) 100% O2
2) Hyperbaric chamber
Treatment for methanol/ethylene glycol intoxication
1) Fomepizol
2) Ethanol
Treatment for Opioid overdose
1) Naloxone (IV)
2) Naltrexone (oral)
Treatment for BZD overdose
1) Flumazenil (BZD antagonist)
Treatment for TCA overdose
1) NaHCO3 (plasma alkalinization)
2) Pt. will present with QRS and QT prolongation
Treatment for Heparin overdose
Protamine
Treatment for Warfarin overdose
1) Vitamin K
2) Fresh frozen plasma
Treatment for tPA overdose
Aminocaproic acid
Treatment for Theophylline overdose
Beta blocker
Drugs that cause cutaneous flushing
Think: VANC
1) Vancomycin (Red man syndrome)
2) Adenosine
3) Niacin
4) Ca Channel blockers
Drugs that cause agranulocytosis
Think: Agranulocytosis Could Certainly Cause Pretty Major Damage
1) Clozapine (atypical antipsychotic)
2) Carbamezpine
3) Colchicine
4) Propylthiouracil
5) Methimazole
6) Dapsone
Drugs that could cause grey baby syndrome
Chloramphenicol
Drugs that can cause hemolysis in G6PD deficienct pt (x-linked)
Think: hemolysis IS PAIN
1) INH
2) Sulfonamides
3) Primaquine
4) Aspirin
5) Ibuprofen
6) Nitrofurantoin
Drugs that cause megaloblastic anemia
Think: having a blast with PMS
1) Phenytoin
2) Methotrexate
3) Sulfa drugs
What drugs can cause pulmonary fibrosis?
think: BLAB
1) BLeomycin
2) Amiodarone
3) Busulfan
What drug can cause hepatitis?
INH
Drugs that cause Pseudomembranous colits to occur?
1) Clindamycin
2) Ampicillin
Drugs that cause Gynecomastia?
Think: Some Drugs Create Awkward Knockers
1) Spironolactone
2) Digitalis
3) Cimetidine (H2 receptor)
4) Alcohol
5) Ketoconazole (anti-fungal)
Drugs that cause myopathies?
Think: Fish N CHIPS Give you myopathies
1) Fibrates
2) Niacin (also causes cutaneous flushing)
3) Colchicine (also causes agranulocytosis)
4) Hydroxychloroquine
5) INF-alpha
6) Penicillamine (Used for gold, arsenic, copper, and lead poisoning)
7) Statins
8) Glucocorticoids
What drugs cause gingival hyperplasia
1) Phenytoin
2) Verapamil
What drugs cause Steven Johnson syndrome
Think: Bad rash after PEC SLAPP
1) Penicillin
2) Ethosuximide
3) Cababazepine
4) Sulfa drugs
5) Lamotrigine
6) Allopurinol
7) Phenytoin
8) Phenobarbital
Drug that causes teeth problems as well as bone problemsproblems
Tetracylcine
Drug that causes tendonitis/ rupture of tendon and cartilage damage
Fluoroquinolones
Drugs that cause nephrotoxicity/ototoxicity
1) Aminoglycans
2) Vancomycin
3) Loop diuretics
4) Cisplatin (cross link dna)
Drugs that induce the P-450
Think: BCG PQRS
1) Barbiturates
2) Carbamazepine
3) Griseofulvin
4) Phenytoin
5) Quinidine
6) Rifampin
Drugs that inhibit P-450
Think: PICK EGS
1) protease inhibitors (Ritanavir)
2) INH
3) Cimetidine/Ciprofloxacin
4) Ketoconazole
5) Erythromycin
6) Grapefruit juice
7) Sulfonamides
What are the sulfa drugs?
Think: Popular FACTSS
1) Probenecid
2) Furosemide
3) Acetazolamide
4) Celecoxib
5) Thiazides
6) Sulfonamide antibiotics
7) Sulfonylureas (Hypoglycemic drug)
Drugs that cause Seizures
think: I BITE My tongue
1) INH
2) Bupropion
3) Imipenem
4) Tramadol
5) Enflurane (local anesthetic)
6) Metclopramide (D2 antagonist)
How is INH metabolized?
Acetylation
What type of drug would have a volume distribution of 3-5L? 14-16L? 41L?
1) Charged or large drug
2) Small molecular weight but is hydrophilic
3) Small molecular weight and is lipophilic
What results with carbon tetrachloride exposure?
Free radical injury that results in hepatic necrosis
Microsomal monoxygenase
cytochrome P450
What is the general affect of general anesthesia?
1) Decreases cardiact output
2) Increases atrial and ventricular pressures
3) Respiratory depressant
3) Fluorinated anesthetics decrease vascular resistance
4) Increase renal vascular resitance
5) Decrease hepatic blood flow
What does an increased arterio-venous gradient for an anesthetic mean?
1) It means the anesthetic has a increased peripheral tissue solubility (aka it is taken up by the tissue fast)
2) This means that less of the anesthetic gets to the brain resulting in a slow onset of action
A 48-year-old male presents to the office with the complaints of diarrhea and an inability to extend his right wrist. History reveals this began a few weeks ago. He states he has worked in an ammunition factory since age 18. Physical examination reveals 2/5 motor strength with right wrist extension. A urinalysis is obtained and is positive for bicarbonate, protein, phosphate, and glucose.
Lead poisoning
