Pharmacology Flashcards
vitamin D analogs
e.g. calcipotriene (calcipotriol), calcitriol, tacalcitol
bind and activate vitamin D receptor (a nuclear TF) –> inhibition of keratinocyte proliferation, stimulation of keratinocyte differentiation, inhibits TC proliferation and other inflammatory mediators
bottom line: anti-inflammatory that is used to tx things like psoriasis
cyclosporine
inhibits NFAT (nuclear factor of activated TCs) –> impairs production and release of IL2 and IL2 induced TC activation
bottom line: anti-inflammatory that is used to tx things like psoriasis
Etanercept
recombinant form of TNF receptor that binds TNF-a
bottom line: anti-inflammatory that is used to tx things like psoriasis, RA, psoriatic arthritis
MTX
folate antimetabolite that reversibly binds to dihydrofolate reductase resulting in inhibition of purine and thymidylic acid synthesis
Ustekinumab
human monoclonal Ab targeting IL-12 and IL-23 –> inhibits activation of CD4 Th1 and Th17 cells
Foscarnet
pyrophosphate analog
indication: ganciclovir-resistant CMV
side effects: Ca chelation, renal wasting of Mg, dec release of PTH
Acyclovir
crystal nephropathy and neurotoxicity manifesting as delirium and/or tremor
Cidofovir
indication: CMV retinitis
side effects: nephrotoxicity (proteinuria and inc Cr)
Lamivudine
NRTI
side effects: rare, occasionally peripheral neuropathy and lactic acidosis
Sofosbuvir
inhibits nonstructural protein 5B, RNA-dependent RNA polymerase needed for HCV replication
Indication: HCV
SE: fatigue, nausea
Valganciclovir
ganciclovir prodrug
SE: severe neutropenia exacerbated by other BM suppressants (eg zidovudine, trimethoprim-sulfamethoxazole)
Ganciclovir
can cause severe neutropenia exacerbated by other BM suppressants (eg zidovudine, trimethoprim-sulfamethoxazole)
Loop diuretics
eg furosemide, bumetanide, torsemide
hypoK, hypoMg, hypoCa, ototoxicity
Thiazide diuretics
eg chlorthalidone, hydrochlorothiazide
act at distal convoluted tubule causing enhanced Na, Cl, and H2O excretion by blocking Na Cl symporters in DCT
hypoK, hypoNa, hyperuricemia, hypercalcemia
K+ sparing diuretics
eg triamterene, sprionolactone
act at collecting duct system
SE: hyperK
Spironolactone: gynecomastia, antiandrogen effects
Carbonic anhydrase inhibitors
eg acetazolamide
act at PCT and straight portion to block reabsorption of NaHCO3
SE: metabolic acidosis
Osmotic diuretics
eg mannitol
act at proximal tubule and descending limb of Loop of Henle to reduce Na and H2O reabsorption
SE: hyperNa, pulmonary edema
Metronidazole
tx anaerobic infections
indictations:
- mild to moderate cases of c. diff (i.e. first and first recurrence)
- Giardia lamblia
- entamoeba histolytica
- trichomonas vaginalis
more extensive absorption so less it delivered to distal colon than vanc and fidaxomicin
vancomycin
po for severe or recurrent c. diff colitis
bactericidal except at doses used to tx c. diff
- binds to terminal D-alanine residues of cell wall glycoproteins and prevents transpeptidases from forming cross-links
minimal systemic absorption
Fidaxomicin
macrocyclic abx
inhibits sigma subunit of RNA pol –> protein synthesis impairment and cell death
i.e. bacteriocidal activity
Advantages:
- minimal systemic absorption
- less effect on normal colonic flora than vanc or metronidazole
Doxycycline indications
clostridial skin infections (C perfringens, C septicum)
Neomycin
bacteriocidal
indications:
- hepatic encephalopathy
- diarrhea 2/2 e. coli
- surgical pphx for GI procedures
chloroquine
tx of choice for sensitive plasmodium species
mefloquine
quinine analog
tx for chloroquine-resistant organisms
Primaquine
given for P. vivax and P. ovale with hypnozoites in addition to chloroquine or mefloquine
Ivermectin
tx for onchocerciasis (river blindness)
Mebendazole
anti-helminthic drug
indications:
- ascariasis
- trichuriasis
- hookworm
- pinworm infections
Nifurtimox
antiparasitic tx Chagas dz (American trypanosomiasis) caused by Trypanosoma cruzi
Pentamidine
- pphyx for PCP PNA
- tx African sleeping sickness and leishmaniasis
Statin severe side effects
- hepatitis
- myopathy (i.e. serum CPK 10x normal and muscle pain) –> especially when combined with fibrates like gemfibrozil and fenofibrate bc they inc statin concentration
- simvastatin = highest risk of myopathy, dose not to exceed 10 mg when concurrently giving fibrates
statin MoA
HMG-CoA redutase inhibitor
bile acid sequestrants can dec its absorption therefore dose at least 4 hrs apart
ezetimibe
dec cholesterol absorption in small intestine
inc risk of myopathy when given with statin but less than when statin given with fibrate
penicillin and cephalosporin MoA
irreversibly bind penicillin-binding proteins, e.g. transpeptidases which normally cross-link peptidoglycan in bacterial cell wall –> leads to cell wall instability and bacteriolysis
diff bacT species synthesize multiple diff penicillin-binding proteins
fluoroquinolones MoA
interfere with DNA replication by binding proteins like DNA gyrase in bacT (akin to topoisomerase II)
Macrolide MoA
binds ribosomal proteins
tetracyclines MoA
binds 30S ribosomal subunit preventing attachment of aminoacyl-tRNA
beta-lactamases
degrade penicillin and cephalosporins thereby preventing binding to pencillin-binding proteins
CTX resistance
structural changes in penicillin-binding proteins
Trimethoprim-sulfamethoxazole resistance
salvage metabolic pathway that circumvents metabolic pathway targeted by drug
Tetracyline and marcrolide resistance
transmembranous efflux pumps that prevent entry into the cell
aminoglycosides MoA
binds 30S and inhibits formation of initiation complex and causes misreading of mRNA
Chloramphenicol MoA
binds 50S and inhibits peptidyl transferase
macrolide MoA
binds 50S and prevents release of uncharged tRNA after it has donated its amino acid
Hydroxyurea
inhibits ribonucleotide reductase interfering with purine synthesis
6-mercaptopurine (6-MP)
blocks de novo purine synthesis
tx gout
5-fluorouracil (5-FU)
inhibits thymidylate synthase (decreases deoxythymidine monophosphate dTMP) interfering with purine synthesis
Methotrexate
inhibits dihydrofolate reductase (decreases dTMP) interfering with purine synthesis
Trimethoprim
inhibits bacterial dihydrofolate reductase (dec dTMP) interfering with purine synthesis
Trazodone
antidepressant
MoA =inhibits 5HT reuptake, alpha-adrenergic blockade, histamine H1 receptor antagonism
side effects = priapism (rare but severe), orthostatic HoTN, sedation
use cautiously when pt has condition predisposing to priapism = sickle cell, multiple myeloma
Tricyclic antidepressants
2nd line therapy
SE = cardiotoxicity
clomipramine = for OCD
Monoamine oxidase inhibitors
dietary restrictions bc of risk for hypertensive crisis (tyrosine, cheese)
Phenelzine = tx of resistant depression
SSRIs
sexual side effects = dec libido, anorgasmia, delayed ejaculation
SNRI
eg duloxetine
Zolpidem
non-benzo hypnotic used to tx insomnia
Clopidogrel
inhibits ADP-induced platelet aggregation
ACEi
tx of CHF, HTN, diabetic nephropathy
Indomethacin
non-specific COX inhibitor –> suppresses prostaglandin synthesis
promotes closure of PDA
Bosentan
competitive endothelin receptor antagonist used to tx idiopathic pulmonary arterial htn
vincristine
vinca alkaloid (also vinblastine)
MoA = inhibits microtubule formation by binding beta-tubulin and preventing polymerization
cell cycle-specific cytotoxicity during M phase (chromosomes can’t align and segregate)
toxicity = dose-dependent, most commonly PERIPHERAL NEUROPATHY
*chemotox man –> arms and legs
Topoisomerase I and II inhibitors
chemo drugs = irinotecan and etoposide
bleomycin
chemotherapeutic targeting G2 phase of cell cycle
MoA = intercalates with DNA and induces free radical formation
SE = lung fibrosis
doxorubicin
chemotherapeutic targeting G2 phase of cell cycle
MoA = intercalates with DNA and induces free radical formation
SE = irreversible dose-induced cardiomyopathy
cell-cycle nonspecific chemotherapeutic agents
cyclophosphamide = alkylating agent; SE include BM suppression, alopecia, hemorrhagic cystitis
Rifampin
inhibits bacT DNA-dependent RNA pol –> blocks DNA transcription
side effects: GI, Rash, Red-orange body fluids, cytopenia
Isoniazid
inhibits mycolic acid synthesis
mycolic acids normally cause mycobacteria to be acid-fast bc they retain the carbofuchsin dye and resist decoloration by acid-alcohol decolorizing agent –> when isoniazid inhibits it, it loses its acid-fast coloration and stop synthesizing new cell walls/proliferating
SE: neurotoxicity (give B6/pyridoxine), hepatotoxicity
Pyrazinamide
unclear MoA
SE: hepatotoxicity, hyperuricemia
Ethambutol
inhibition of arabinosyl transferase
SE: optic neuropathy
Amphotericin B
most toxic antifungal
tx for disseminated histoplasmosis
nephrotoxicity c/b dec in GFR and toxic effects on tubular epithelium –> increased permeability of distal tubule –> hypoK, hypoMg –> weakness and arrhythmias –> EKG shows T wave flattening, ST depression, U waves, PAC, PVC –> profound hypoK get vtach or vfib
glucocorticoids and osteoporosis
- inc osteoclast differentiation and activity
- dec osteoblast activity
- inhibiting intestinal action of Vit D in promoting Ca absorption
- inc PTH levels
occurs if taken daily for >6 mo
can also occur with topical intake, eg inhaler
Meds associated with osteoporosis
- anticonvulsants that induce CYP450 - phenobarb, phenytoin, carbamazepine. inc vit D catabolism
- aromatase inhibitors - dec estrogen
- medroxyprogesterone - “
- GnRH agonists - dec testosterone and estrogen
- PPIs - dec Ca absorption
- unfractionated heparin - dec bone formation
- glucocorticoids - “
- thiazolidinediones - “
Tx for hyperammonemia
benzoate or phenylbutyrate = bind aa and lead to excretion
lactulose = acidifies GI tract and traps NH4+ so you poop it out
volume of distribution (Vd)
Vd = amount of drug in body / plasma drug concentration
theoretical fluid volume required to maintain total absorbed drug amount at the plasma concentration
Vd of plasma protein-bound drug can be altered by liver and kidney disease (dec protein binding inc Vd)
half-life (t1/2)
0.7 x Vd
________
Clearance
a drug infused at a constant rate takes 4-5 half-lives to reach steady state
Clearance (CL)
rate of drug elimination = Vd x Ke (elimination constant)
____________________
plasma drug concentration
Loading dose
Cp X Vd / F
Cp = target plasma concentration
Maintenance dose
Cp x CL / F
Zero-order elimination
constant amount of drug-eliminated per unit time
Cp dec linearly with time
e. g. PEA (round like 0)
- Phenytoin
- Ethanol
- Aspirin
First-order elimination
constant fraction of drug eliminated per unit time
Cp dec exponentially with time
Phase I metabolism
Reduction, oxidation, hydrolysis with P450 –> slightly polar water-soluble metabolites (still active usually)
Geriatric patients lose this first
Phase II metabolism
Conjugation (Glucuronidation, Acetylation, Sulfation) –> very polar, inactive metabolites that are renally excreted
Geriatric patients have GAS
slow acetylators –> greater side effects bc it dec rate of metabolism
Competitive antagonist
shifts curve to the right –> dec potency, no change in efficacy
can overcome by inc concentration of agonist substrate
e.g. Diazepam + flumazenil on GABA receptor
Noncompetitive antagonist
shifts curve down –> dec efficacy
can’t be overcome by inc agonist substrate
e.g. NE + phenoxybenzamine on alpha receptor
Partial agonist
acts at same site as full agonist, but with reduced maximal effect –> dec efficacy
potency is variable and can be inc or dec
e.g. morphine (full agonist) + buprenorphine (partial agonist) at opioid mu-receptor
Therapeutic index
LD50/ED50
median lethal dose / median effective dose
what two systems are part of the SNS but innervated by cholinergic neurons?
Adrenal medulla
Sweat glands
Nicotinic ACh receptors
ligan-gated Na/K channels
Nn found in autonomic ganglia
Nm found in NMJ
Muscarinic ACh receptors
GPCRs acting through 2nd messengers
5 subtypes:
M1-5
alpha-1 receptors
G-protein class: q
Major functions:
- inc vascular smooth muscle contraction
- inc pupillary dilator muscle (mydriasis)
- inc intestinal and bladder sphincter muscle contraction (i.e. can’t go to bathroom when running from a bear)
alpha-2 receptors
G-protein class: i
Major functions:
- dec sympathetic outflow
- dec insulin release
- dec lipolysis
- inc platelet platelet aggregation
beta-1 receptors
G-protein class: s
Major functions:
- inc heart rate
- inc contractility
- inc renin release
- inc lipolysis
beta-2 receptors
G-protein class: s
Major functions:
- vasodilation
- bronchodilation
- inc heart rate
- inc contractility
- inc lipolysis
- inc insulin release
- dec uterine tone (tocolytic)
- ciliary muscle relaxation
- inc aqueous humor production –> hence can use for glaucoma
M1 receptors
G-protein class: q
Major functions:
- CNS
- enteric nervous system
M2 receptors
G-protein class: i
Major functions:
- dec HR
- dec contractility of atria
M3 receptors
G-protein class: q
Major functions:
- inc exocrine gland secretions (eg lacrimal, gastric acid)
- inc gut peristalsis
- inc bladder contraction
- bronchoconstriction
- inc pupillary sphincter muscle contraction (miosis)
- ciliary muscle contraction (accomodation)
D1 receptors
G-protein class: s
Major functions:
-relaxes renal vascular smooth muscle
D2 receptors
G-protein class: i
Major functions:
-modulates transmitter release especially in the brain
H1 receptors
G-protein class: q
Major functions:
- inc nasal and bronchial mucus production
- contraction of bronchioles
- pruritus
- pain
H2 receptors
G-protein class: s
Major functions:
-inc gastric acid secretion
vasopressin 1 (v1) receptor
G-protein class: q
Major functions:
-inc vascular smooth muscle contraction
vasopressin 2 (v2) receptor
G-protein class: s
Major functions:
-inc H2O permeability and reabsorption in collecting tubules of the kidney
i.e. this is were vasopressin = ADH acts
V2 is found in the two kidneys
Bethanechol
direct cholinergic agonist
Postoperative ileus, neurogenic ileus, urinary retention
- activates bowel and bladder smooth muscle
- resistant to AChE
Carbachol
direct cholinergic agonist
Glaucoma, pupillary contraction, relief of intraocular pressure
carbon copy of acetylcholine
Pilocarpine
direct cholinergic agonist
potent stimulator of sweat, tears, saliva, open-angle and closed-angle glaucoma
- contracts ciliary muscle of eye (open-angle glaucoma)
- contracts pupillary sphincter (closed-angle glaucoma)
- resistant AChE
Methacholine
direct cholinergic agonist
challenge test for dx of asthma
stimulates muscarinic receptors in airway when inhaled
Neostigmine
indirect choline agonist, i.e. anticholinesterase
postop and neurogenic ileus and urinary retention, myasthenia gravis, reversal of NMJ blockade (postop)
inc endogenous ACh
Neo CNS = No CNS penetration
Pyridostigmine
indirect choline agonist, i.e. anticholinesterase
myasthenia gravis (long acting); doesn’t cross BBB
inc endogenous ACh, inc strength
Edrophonium
indirect choline agonist, i.e. anticholinesterase
Dx of myasthenia gravis (extremely short acting)
inc endogenous ACh
Physostigmine
indirect choline agonist, i.e. anticholinesterase
anticholinergic toxicity (crosses BBB)
inc endogenous ACh
“Physostigmine phyxes atropine overdose”
Donepezil
indirect choline agonist, i.e. anticholinesterase
Alzheimer’s disease
inc endogenous ACh
what do you look out for in predisposed patients with all cholinomimetic agents?
COPD exacerbation
asthma
peptic ulcers
Cholinesterase inhibitor poisoning
organophosphates e.g. parathion
irreversibly inhibit AChE
sx: DUMBBBELSS
- Diarrhea
- Urination
- Miosis
- Bronchospasm
- Bronchorrhea
- Bradycardia
- Excitation of skeletal muscle and CNS
- Lacrimatoin
- Sweating
- Salivation
antidote = atropine and pralidoxime (regenerates active AChE)
Benztropine
antimuscarinic
use for Parkinson’s (improves tremor) and dystonia 2/2 antipsychotics
Scopolamine
antimuscarinic
use for motion sickness
oxybuynin
antimuscarinic
use to reduce urgency in mild cystitis and reduce bladder spasms
glycopyrrolate
antimuscarinic - decrease GI and respiratory secretions
Parenteral: preop use to reduce airway secretions
PO: drooling, peptic ulcers
Atropine toxicity = anticholinergic toxidrome
Hot as a hare Dry as a bone Red as a beet Blind as a bat Mad as a hatter
Jimson weed (Datura) –> gardener’s pupil mydriasis due to plant alkaloids)
Epinephrine selectivity
non-selective alpha
NE selectivity
non-selective alpha activity, some beta1 activity
tx HoTN but dec renal perfusion
Isoproterenol selectivity
non-selective beta activity
tx torsade de pointes (tachycardia dec QT interval), bradyarrhythmias (but can worsen ischemia)
Dopamine selectivity
high dose - non-selective alpha
medium dose - B1 > B2
low dose - DA activity
tx shock (renal perfusion), heart failure
- inotropic
- chronotropic
Dobutamine selectivity
low alpha activity
B1»_space; B2
tx heart failure, cardiac stress testing
- inotropic
- chronotropic
phenylephrine selectivity
alpha 1 > alpha 2
tx HoTN, ocular procedures (mydriatic), rhinitis
albuterol, salmeterol, terbutaline selectivity
beta 2»_space; beta 1
ritodrine selectivity
beta 2
tocolytic
beta1 and reflex activity of isoproterenol
little alpha effect but causes beta2-mediated vasodilation –> dec mean arterial pressure and inc heart rate
vs.
NE:
inc systolic and diastolic pressure through alpha1-mediated vasoconstriction –> inc MAP –> bradycardia
sympathoplegics
clonidine and alpha-methyldopa
centrally acting alpha2-agonists –> dec central sympathetic outflow
use for HTN especially with renal disease since you don’t get decreased perfusion to kidney like you do with alpha1 agonism
Phenoxybenzamine
irreversible nonselective alpha blockade
use prior to pheochromocytoma resection because released catecholamines won’t overcome block
epinephrine vs phenylephrine
epinephrine = beta > alpha blockade therefore when you do alpha blockade you actually get a reversal (net decrease) in mean blood pressure because of beta2 action when you administer E
phenylephrine = just alpha blockade therefore when you co-administer with an alpha blocker you see a suppression of the mean arterial pressure to normal without phenylephrine but not a reversal (net decrease) like you see with E
beta blockers and MI
decreases mortality
beta blockers and SVT
metoprolol, esmolol
dec AV conduction velocity = class II antiarrhythmic
HTN and beta blockers
beta1 receptor blockade on JGA cells
beta1-selective antagonists
A BEAM of beta1 blockers.
Use for patients with comorbid pulmonary disease
Acebutolol (partial agonist) Betaxolol Esmolol (short acting) Atenolol Metoprolol
Nonselective beta antagonists
Please Try Not Being Picky
Propranolol
Timolol
Nadolol
Pindolol
Nonselective (vasodilatory) alpha and beta antagonists
carvedilol and labetalol
Partial beta Agonists
PAPA
Pindolol
Acebutolol
Digitalis antidote
K+ normalization
Lidocaine
Anti-dig Fab fragments
Mg2+
Lead antidote
CaEDTA
Dimercaprol
Succimer
Penicillamine
Cyanide antidote
Nitrite + thiosulfate
hydroxocobalamin
Heparin antidote
protamine
tPA, streptokinase, urokinase antidote
aminocaproic acid
what drugs cause torsades de pointes?
class III (sotalol) and class IA (quinidine) antiarrhythmics
what drugs cause agranulocytosis?
Agranulocytosis Could Certainly Cause Pretty Major Damage
Clozapine Carbamazepine Colchicine Propylthiouracil Methimazole Dapsone
what drugs cause hemolysis in G6PD deficient patients?
oxidizing drugs
Isoniazid Sulfonamides Primaquine Aspirin Ibuprofen Nitrofurantoin
what drugs cause megaloblastic anemia?
Having a blast with PMS
Phenytoin
MTX
sulfa drugs
what drugs cause pulmonary fibrosis?
Bleomycin
Amiodarone
Busulfan
what drugs cause focal to massive hepatic necrosis?
Halothane
Amanita phalloides
Valproic acid
Acetaminophen
what drugs cause pseudomembranous colitis?
Clindamycin
ampicillin
what drugs cause gynecomastia?
Some Drugs Create Awkward Knockers
Spironolactone Digitalis Cimetidine chronic Alcohol use estrogens Ketoconazole
what drugs cause hyperglycemia?
Niacin tacrolimus (immunosuppressant) protease inhibitors HCTZ corticosteroids
what drugs cause gout?
furosemide
thiazides
niacin
cyclosporine
what drugs cause myopathies?
Fish N CHIPS Give you myopathies
Fibrates Niacin Colchicine Hydroxychloroquine Interferon-alpha Penicillamine Statins Glucocorticoids
what drugs cause Stevens-Johnson syndrome?
Penicillin Ethosuximide Carbamazepine Sulfa drugs Lamotrigine Allopurinol Phenytoin Phenobarbital
Bad rash after a PEC SLAPP
what drugs cause SLE-like syndrome?
Hydralazine
INH
Procainamide
Phenytoin
It’s not HIPP to have lupus.
what drugs cause tendonitis, tendon rupture and cartilage damage?
fluoroquinolones
what drugs cause diabetes insipidus?
demeclocycline, Lithium
what drugs cause seizures?
“with seizures I BITE My tongue”
Isoniazid Bupropion Imipenem/cilastatin Tramadol Enflurane Metoclopramide
what drugs cause a disulfiram-like reaction?
metronidazole
certain cephalosporins
procarbazine
1st generation sulfonylureas
what drugs cause nephrotoxicity/ototoxicity?
aminoglycosies
vancomycin
loop diuretics
cisplatin
P450 inducers
“Momma Barb Steals Phen-phen and Refuses Greasy Carbs Chronically”
Modafinil Barbiturates St. John's wort Phenytoin Rifampin Griseofulvin Carbamazepine Chronic alcohol use
P450 Inhibitors
“MACIG RACKS in GQ”
Macrolides Amiodarone Grapefruit juice Isoniazid Cimetidine Ritoniavir Acute Alcohol abuse Ciprofloxacin Ketoconazole Sulfonamides Gemfibrozil Quinidine
Sulfa drugs
Popular FACTSSS
Probenecid Furosemide Acetazolamide Celecoxib Thiazides Sulfonamide abx Sulfasalazine Sulfonylureas
sx of allergy = fever, UTI, rash, SJS, hemolysis, thrombocytopenia, agranulocytosis, hives
-triptan
5-HT 1B/1D agonists used for migraines
-azine
Phenothiazine (neuroleptic, antiemetic)
e.g. chlorpromazine
-oxin
cardiac glycoside = inotropic agent
eg digoxin
what drug is protective against diabetic nephropathy?
ACEi
Hydralazine
inc cGMP –> smooth muscle relaxation
vasodilation of arterioles > veins –> afterload reduction
first-line therapy for HTN in pregnancy with methyldopa
- give beta-blocker to prevent reflex tachycardia
SE: compensatory tachycardia (don’t give with angina/CAD), fluid retention, nausea, HA, angina, Lupus-like syndrome
nitroprusside
short-acting, inc cGMP via direct release of NO
look out for cyanide toxicity
Fenoldopam
dopamine D1 receptor agonist - coronary, peripheral, renal, splanchnic vasodilation
dec BP, inc natriuresis
HMG-CoA MOA
inhibit conversion of HMG-CoA to mevalonate = cholesterol precursor
niacin as lipid-lowering agent
inhibits lipolysis in adipose tissue; reduces hepatic VLDL secretion into circulation
bile acid resins MoA
cholestyramine, colestipol, colesevelam
prevent intestinal reabsorption of bile acids –> liver has to use cholesterol to make more
SE = dec absorption of fat-soluble vitamins, cholesterol gallstones
cholesterol absorption blockers
ezetimibe
prevent cholesterol absorption at small intestine brush border
drugs that inc HDL
HMG-CoA
Niacin
slightly bile acid resins
fibrates
drugs that dec TG the most
fibrates (gemfibrozil, clofibrate, bezafibrate, fenofibrate)
Digoxin toxicity findings including EKG
half-life = 40 hours, excreted in urine
cholinergic - n/v/d, blurry yellow vision
EKG - inc PR, dec QT, ST scooping, T inversion, arrhythmia, AV block
hyperkalemia = poor prognosis
factors predisposing to toxicity:
- renal failure
- hypokalemia (permissive for digoxin binding at K binding site on NaK ATPase)
- quinidine (dec digoxin clearance, displaces digoxing from tissue-binding sites)
Class I antiarrhythmics
Na channel blockers
- local anesthetics
- block or slow conduction
- dec slope of phase 0 depolarization
- inc threshold for firing in abnormal pacemaker cells
- state dependent - selectively depresses more frequently depolarized tissue, e.g. tachycardia
- hyperkalemia causes inc toxicity
Class IA
“The Queen Proclaims Diso’s Pyramid”
Quinidine, Procainamide, Disopyramide
MoA: inc AP duration, inc effective refractory period
Indication: atrial and ventricular arrhythmias, especially reentrant and ectopic SVT and VT
Toxicity:
quinidine - HA, tinnitus
procainamide - reversible SLE-like syndrome
disopyramide - heart failure
general - thrombocytopenia, torsades due to inc QT interval
Class IB
“I’d Buy Lidy’s Mexican Tacos”
Lidocaine, Mexiletine, Tocainide
MoA: dec AP duration; Preferentially affect ischemic or depolarized Purkinje and ventricular tissue
Indication: acute ventricular arrhythmias esp POST-MI and in digitalis-induced arrhythmias
toxicity: local anesthetic, CNS stimulation/depression, CV depression
Class IC
Flecainide, propafenone
MoA: No effect on AP duration. Useful in ventricular tachycardias that progress to VF and in intractable SVT.
Indication: last reosrt in tachyarrhythmias. For pts without structural abnormalities.
IC is Contraindicated in structural heart disease and post-MI!!!
Toxicity: proarrhythmic, especially post-MI. Significantly prolongs refractory period in AV node
Class II
beta-blockers: metoprolol, propranolol, esmolol, atenolol, timolol
MoA: dec SA and AV node activity by dec cAMP, dec Ca currents. dec slope of phase 4
indicated for Vtach, SVT, slowing ventricular rate during a-fib and a-flutter
toxicity: impotence, exacerbation of asthma, CV effects (bradycardia, AV block, CHF), CND effects (sedation, sleep alterations). may mask signs of hypoglycemia.
metoprolol can cause dyslipidemia. tx overdose with glucagon.
Propranolol can exacerbate Prinzmetal’s angina.
Class III
“AIDS”: amiodarone, ibutilide, dofetilide, sotalol
MoA: inc AP duration, inc effective refractory period
indication: when other antiarrhythmics fail. inc QT interval
toxicity:
- sotalol-torsades, excessive beta block
- ibutilide - torsades
- amiodarone - pulmonary fibrosis, hepatotoxicity, hypothyroidism/hyperthyroidism, corneal deposits, skin deposits (blue/gray) leading to photodermatitis, neuro effects, constipation, CV effects (bradycardia, heart block, CHF)
amiodarone = class I, II, III, IV effects bc it alters the lipid membrane –> check PFTs, LFTs, and TFTs
Class IV
calcium channel blockers: verapamil, diltiazem
MoA: dec doncution velocity, inc effective refractory period, inc PR interval
indication: prevention of nodal arrhythmias, eg SVT
toxicity: constipation, flushing, edema, CV (CHF, AV block, SA depression)
Adenosine
inc K out of cells –> hyperpolarizes cell and dec Ca current
indication: SVT, short acting (~15 sec)
toxicity: flushing, hypotension, chest pain
effects blocked by theophylline and caffeine
Mg as antiarrhythmic
effective in torsades and digoxin toxicity
Biguanides
eg metformin
inc insulin sensitivity
SE: lactic acidosis (contraindicated in renal failure)
Sulfonylureas
eg. Tolbutamide, Glyburide, Glipizide
close K channel in beta cell membrane –> depol -> inc [Ca}i –> insulin release
*requires some islet cell fxn therefore can’t use in DM1
Glitazones / thiazolidinediones
eg Pioglitazone, rosiglitazone
- inc insulin sensitivity in peripheral tissues
- binds PPAR-gamma nuclear transcription regulator (fatty acid storage and glucose metabolism, activation causes inc insulin sensitivity and adiponectin)
SE: weight gain, edema, hepatotoxicity
alpha-glucosidase inhibitors
acarbose, miglitol
inhibits intestinal brush border alpha-glucosidases –> delayed sugar hydrolysis and glucose absorption –> dec postprandial hyperglycemia
amylin analogs
pramlintide
dec glucagon
used in DM 1 and 2
SE: hypoglycemia, n/d
glp-1 analogs
exenatide, liraglutide
inc insulin, dec glucagon release
used only in type 2 DM
SE: n/v, pancreatitis
DPP-4 inhibitors
linagliptin, saxagliptin, sitagliptin
inc insulin, dec glucagon release
only used in DM2
SE: mild urinary and respiratory infections
Propylthiouracil, methimazole
block peroxidase –| organification of iodide and coupling of thyroid hormone synthesis, i.e. I- to I2
propyl also –| 5’deiodinase which is responsible for conversion of T4 to T3 peripherally
SE: skin rash, rarely AGRANULOCYTOSIS, aplastic anemia, hepatotoxicity (propylthiouracil).
Methimazole also a possible TERATOGEN.
Levothyroxine, triiodothyronine
hypothyroidism, myxedema
se: tachycardia, heat intolerance, tremors, arrhythmias
octreotide indications
acromegaly, carcinoid, gastrinoma, glucagonoma, esophageal varices
Demeclocycline toxicity
used for SIADH bc it is an ADH antagonist
can cause nephrogenic DI, photosensitivity, abnormalities of bone and teeth (bc it’s a member of tetracycline family)
glucocorticoid mechanism of action
dec production of leukotrienes and prostaglandins by inhibiting phospholipase A2 and expression of COX-2
Ticlopidine and clopidogrel
irreversible blockade of ADP receptor (responsible for helping platelet adhere to endothelium and inducing GpIIb/IIIa expression)