Pharm Flashcards
Km
inversely related to the affinity of the enzyme. Km = [S] at 1/2Vmax
if Km is bigger, means the enzyme doesn’t bind as well to the substrate, since you need more enzyme to achieve 1/2 max velocity
how long does it take for a drug infused at a constant rate to reach steady state?
4-5 half-lives
half-life equation
(0.693 x Vd) / CL
Clearance
volume of plasma cleared of drug / time
rate of drug elimination / plasma drug concentration = Vd X elimination constant
loading dose
(target plasma concentration x volume of distribution) / (bioavailability)
maintenance dose
(Cp x CL x dosage interval) / bioavailability
zero-order elimination + examples
rate of elimination constant, regardless of time. Cp dec. linearly w/ time.
Phenytoin, Ethanol, Aspirin
1st order elimination
constant fraction drug eliminated per unit time
competitive antagonist + example
1) dec. potency, but doesn’t change efficacy (shift right)
ex: diazepam + flumazenil
noncompetitive antagonist + examples
dec. efficacy –> shift curve down
ex: norepinephrine + phenoxybenzamine (note: phenoxy = irreversible competitive antagonist)
partial agonist
acts at same site as full agonist. lower efficacy –> shift down
morphine vs. buprenorphine
Nictoinic vs. muscarinic AcH receptors
1) nicotinic = ligand-gated Na/K channels
2) muscarinic = G-protein coupled receptors w/ 2nd messengers
Parasympathetic
1) cardiac + smooth muscle, gland cells, nerve terminals (muscarinic; M2 = cardiac, M3 = everywhere else)
Sympathetic innervation
1) sweat glands (muscarinic)
2) cardiac / smooth muscle: NE on alpha/beta
3) renal vasculature: D1 / D2
a1
incr:
- vascular smooth muscle
- pupillary dilator contraction
- intestinal / blader sphincter contraction
a2
dec:
- symp. outflow
- insulin release
- lipolysis
incr:
-platelet aggregation
b1
incr:
- HR
- contractility
- renin release
dec. :
- lipolysis
b2:
vasodilation, bronchodilation.
incr. :
- HR
- contractility
- lipolysis
- insulin release
- aqueous humor
dec. :
- uterine tone
M1
CNS / enteric nervous system
M2
dec. HR / atrial contraction
M3
incr:
- exocrine gland secretions (lacrimal, salivary, gastric acid)
- gut peristalsis
- bladder contraction / bronchoconstriction
- pupillary sphincter contraction
D1
renal vascular smooth muscle
D2
modulates transmitter release in brain
H1
incr:
- nasal / bronchial mucous production
- vascular permeability
contraction of bronchioles, pruritis, pain
H2
incr:
-gastric acid secretion
V1
Incr. vascular smooth muscle contraction
V2
incr. H2O permeability + reabsorption in collecting tubules of the kidney
Gq downstream
phospholipase C –> Dag:
1) protein kinase C
2) IP3 –> incr. ca2 –> smooth muscle contraction
Gs receptor mechanism
Gs –> adenylyl cyclase –> ATP conversion to cAMP –> protein kinase A –> incr. Ca2+ in heart
Gi receptor mechanism
inhibition of adenylyl cyclase –> ATP conversion to cAMP –> protein kinas A –> inhibition of myosin light chain kinase in smooth muscle
direct agonists of cholinomimetic agents
1) bethanechol
2) carbachol
3) pilocarpine
4) methacholine
bethanechol
1) activates bowel / bladder smoothmuscle
2) resistant to AChe
carbachol:
1) glacuoma, pupillary constriction, relief of intraocular pressure
pilocarpine
1) stimulates sweat, tears, saliva for open / closed angle glaucoma
methacholine
challenge test for asthma diagnosis
anticholinesterases
1) neostigmine
2) pyridostigmine
3) physostigmine
4) donepezil, rivastigmine, galantamine
5) edrophonium
all increase endogenous Ach
neostigmine
1) ileus / urinary retention, reversal of NMJ blockade (DOES NOT CROSS CNS)
pyridostigmine
myasthenia gravis (long acting) –> does not penetrate CNS
physostigmine
anticholinergic toxicity –> crosses blood-brain barrier
can fix atropine overdose
muscarinic antagonists
1) atropine
2) benztropine
3) scopolamine
4) ipratropium
5) oxybutynin
6) glycopyrrolate
atropine
muscarinic antagonist:
1) increases pupil dilation
2) dec. airway / stomach secretions
3) dec. motility
4) dec. cystitis urgency
epinephrine selectivity:
B > a
norepinephrine selectivity
a1 > a2 > B1
isoproterenol selectivity
B1 = B2
dopamine selectivity
D1 = D2 > B > a
dobutamine selectivity
B1 > B2
phenylephrine selectivity
a1 > a2
albuterol, salmeterol, terbutaline selectivity
B2 > B1
hyperglycemia as sfx drugs
Taking Pills Necessitates Having Blood Checked Tacrolimus Protease inhibitors Niacin HCTZ B-blocker Corticosteroid
hypothyroidism as sfx drugs
lithium
amiodarone
sulfonamide
Hepatic necrosis as sfx
liver "HAVAc" Halothane Amanita phalloides Valproic acid Acetaminophen
Pnacreatitis as sfx
Drugs Causing A Violent Abdominal Distress Didanosine Corticosteroids Alcohol Valproic acid Azathioprine Diuretics (furosemide)
Agranulocytosis as drug rxn
Drugs CCCrush Myeloblasts / Promyelocytes
Dapsone Clozapine Carbamazepine Colchicine Methimazole PTU
Aplastic anemia as drug rxn
Can’t Make New Blood Cells Properly
Carbamazepine Methimazole NSAIDs Benzene Chloramphenicol PTU
Gray baby syndrome = pale skin (somewhere abroad)
chloramphenicol
Hemolysis in G6PD
IS D PAIN
INH Sulfonamide Dapsone Primaquine Aspirin Ibuprofen Nitrofurantoin
Megaloblastic anemia
PMS
Phenytoin
Methotrexate
Sulfadrugs
Thrombocytopenia
Heparin
Cimetidie
Gingival hyperplasia drugs
phenytoin, verapamil, cyclosporin, nifedipine
Hyperuricemia drugs
Painful Tophi & Feet Need Care Pyrazinamide Thiazides Furosemide Niacin Cyclosporine
myopathy drugs
fibrates, niacin, colchicine, hydroxychloroquine, interferon-alpha, penicillamine, statins, glucocorticoids
photosensitivity drugs
SAT For Photo Sulfonamides Amiodarone Tetrayclines 5-FU
Rash / Stevens-Johnson syndrome
SJ has Epileptic Allergy to Sulfa drugs + Penicillin
-anti-epileptic (ethosuximide, carbamazepine, lamotrigine, phenytoin, phenobarbital)
Allopurinol
Sulfa drugs
Penicillin
SLE-syndrome drugs
Sulfa Hydralazine INH Procainamide Phenytoin Etanercept
Parkinson-like drugs
Cogwheel rigidity of ARM
Antipsychotics
Reserpine
Metoclopramide
Seizures
I BITE My tongue INH (vit. B6 def) buproprion Imipenem/cilastin Tramadol Enflurane metoclopramide
SIADH drugs
Can’t Concentrate Serum Sodium
Carbamazepine
Cyclophosphamide
SSRIs
Pulmonary fibrosis drugs
Breathing Air Badly from Meds Bleomycin Amiodarone Busulfan Methotrexate
Disulfiram-like drugs
Metronidazole, cephalosporins, griseofulvin, procarbazine, 1st gen sulfonylurea
Nephrotoxicity / ototoxicity drugs
aminoglycosides
vancomycin
loop diuretics
cisplatin
Sulfa drugs
Probenecid Furosemide Acetazolamide Celecoxib Thiazides Sulfonamide Sulfasalazine Sulfonylurea
