Pharmacology Flashcards
How many half-lifes does it take for a drug infused at a constant rate to reach steady state?
–>4-5 half-lives
List 3 drugs with zero-order elimination?
“PEA”
- Phenytoin
- Ethanol
- Aspirin
Phase 1 drug metabolism:
–>Involves cytochrome P-450
- Reduction, Oxidation, Hydrolysis
- Usually yields slightly polar, water-soluble metabolites (often still active)
- lost first in geriatric patients
Phase 2 drug metabolism:
–>involves conjugation
- “GAS”
- Glucuronidation
- Acetylation
- Sulfation
- Usually yileds very polar, inactive metabolites, that are renally excreted
- Geriatric patients retain GAS (phase 2)!
- pts who are slow acetylators –> slower rate of drug metabolism –> increased side effects from certain drugs
Efficacy:
proportional to Vmax
Potency:
inversely proportion to Km
–>same as affinity for receptor
Therapeutic Index (TI):
“TILE”
TI = LD50/ED50
- LD50: median lethal dose
- ED50: median effective dose
- decreased TI –> more lethal
- safer drugs have higher TI values
What type of receptors are Nicotinic ACh receptors?
–>Ligand-gated Na/K channels
What type of receptors are Muscarinic ACh receptors?
–> G-protein-coupled receptors; act through second messengers.
4 Direct cholinergic agonists:
- Bethanochol
- Carbachol
- Pilocarcpine
- Methacholine
6 Indirect cholinergic agonists = Anti-cholinesterases:
- Neostigmine
- Physostigmine
- Pyridostigmine
- Edrophonium
- Echothiophate
- Donepezil
Bethanechol:
- mechanism?
- action?
- uses?
Direct cholinergic agonist
- activates bowel and bladder smooth muscle
- resistant to AChE
- Uses:
- postoperative neurogenic ileus and urinary retention
Carbachol:
- mechanism?
- uses?
- direct cholinergic agonist
- Treatment of:
- gluacoma
- pupillary contraction
- relief of intraocular pressure
Pilocarpine:
- direct cholinergic agonist
- resistant to AChE
- stimulates sweat, tears, saliva
- contracts ciliary muscle of eye
- contracts pupillary sphincter of eye
Methacholine:
- direct cholinergic agonist
- stimulates muscarinic receptors in airway when inhaled (causing bronchoconstriction)
*Used as challenge test for asthma diagnosis
Neostigmine:
- indirect cholinergic agonist = anti-Cholinesterase
- increases endogenous ACh
- NO CNS penetration
- Uses:
- postoperative and neurogenic ileus and urinary retention
- myasthenia gravis
- reverses neuromuscular junction blockade (post-operatively)
Pyridostigmine:
- indirect cholinergic agonist = anti-cholinesterase
- increases endogenous ACh
- NO CNS penetration
- Use:
- Myasthenia Gravis (“gets RID of myasthenia gravis!”) (trtment b/c it’s long-acting)
Edrophonium:
- indirect cholinergic agonist = anti-cholinesterase
- increases endogenous ACh
- Use:
- Dx of Myasthenia Gravis (b/c it’s really short-acting)
Physostigmine:
- indirect cholinergic agonist = anti-cholinesterase
- increases endogenous ACh
- Uses:
- Atropine overdoes (“Phyxes atropine overdose”)
- Glaucoma (b/c can cross BBB, penetrate CNS)
Echothiophate:
- indirect cholinergic agonist = anti-cholinesterase
- increase endogenous ACh
- treats Glaucoma
Donepezil:
- indirect cholinergic agonist = anti-cholinesterase
- increases endogenous ACh
- treats Alzheimer’s
Which cholinomimetic agents (cholinergic agonists) can be used to treat glaucoma?
Direct: Carbachol and Pilocarpine
Indirect: Physostigmine and Echothiophate
Pralidoxime:
- ->treatment of cholinesterase-inhibitor poisoning (too much ACh)
- ->action = regenerates AChE
Parathion:
–>insecticide = organophosphate = irreversible cholinesterase-inhibitor
Symptoms of cholinesterase-inhibitor / Organophosphate Poisoning:
- ->”DUMBBELSS”
- Diarrhea
- Urination
- Miosis
- Bronchospasm
- Bradycardia
- Excitation of skeletal muscle and CNS
- Lacrimation
- Sweating
- Salivation
Antidote/Treatment of organophosphate/cholinesterase-inhibitor poisoning?
–> Atropine + Pralidoxime (generates active AChE)
Homatropine:
- -> anti-choinergic (like atropine)
- acts on eye
- Causes:
- mydriasis
- cycloplegia (paralyzes ciliary muscle)
Tropicamide:
- -> anti-choinergic (like atropine)
- acts on eye
- Causes:
- mydriasis
- cycloplegia (paralyzes ciliary muscle)
Benztropine:
- anti-cholinergic
- acts on CNS
- treats Parksinon’s (improves tremor and rigidity from excess cholinergic activity; no effect on dopamine levels or bradykinesia)
Scopolamine:
- anti-cholinergic
- acts on CNS
- Treats motion sickness (“want to vomit as I scope out the window of the moving car”)
Ipratropium:
- anti-cholinergic
- acts on respiratory system
- Treats Asthma and COPD (“I Pray I can breathe soon!”)
Oxybutynin:
- anti-cholinergic
- acts on genitourinary system
- reduces urgency in mild cystitis and reduces bladder spasms
Glycopyrrolate:
- anti-cholinergic
- acts on genitourinary system
- reduces urgency in mild cystitis and reduces bladder spasms
Methscopolamine:
- anti-cholinergic
- acts on GI system
- treats peptic ulcers
Propantheline:
- anti-cholinergic
- acts on GI system
- treats peptic ulcers
Atropine:
- mechanism?
- uses?
- effects on: eye, airway, stomach, gut, bladder?
- anti-cholinergic
- Uses:
- treats bradycardia (like from an inferior MI)
- ophthalmic applications (produces mydriasis and cycloplegia)
- Blocks “DUMBELSS” (anti-cholinesterase/organophosphate poisoning)
- Effects on:
- Eyes –> mydriasis, cycloplegia
- Airway –> decreases secretions
- Stomach –> decreases acid secretions
- Gut –> decreases motility
- Bladder –> decreases urgency in cystitis
Atropine Toxicity:
- Hot as a hare (increased body temp)
- Dry as a bone (decreased sweating, dry mouth, dry skin)
- Red as a beet (flushed skin)
- Blind as a bat (cycloplegia; and can cause acute angle-closure glaucoma in elderly)
- Mad as a hatter (disorientation)
- Bloated as a toad (constipation; also, urinary retention in men with prostatic hyperplasia)
Epinephrine:
- acts on which receptors?
- uses?
*acts on alpha1, alpha2, beta1, beta2
- uses:
- Anaphylactic shock
- open angle Glaucoma
- Asthma
- Hypotension
Norepinephrine:
- acts on which receptors?
- uses?
-acts on alpha1 and alpha2, and less-so on beta1
- Uses:
- Hypotension
- Septic shock
Isoproterenol:
- acts on which receptors?
- uses?
- acts equally on beta1 and beta2
- treats AV block
Dopamine:
- acts on which receptors?
- uses?
- Effects are dose-dependent!
- High Doses –> acts on alpha1 and alpha2
- Medium Doses –> acts on beta1 > beta2
- Low Dose –> acts on D1
- Uses:
- increases renal perfusion in shock and heart failure
- Inotropic (stimulates contractions) and Chronotropic (changes heart rate)
Dobutamine:
- acts on which receptors?
- uses?
-mostly acts on Beta1, but also slightly on alpha1, alpha2, beta2
- uses:
- Heart failure
- Cardiac stress testing
- Cardiogenic shock
Phenylephrine:
- acts on which receptors?
- uses?
-mostly alpha 1, some alpha2
- Applications:
- pupillary dilation
- vasoconstriction
- nasal decongestion
- good for stopping epistaxis!
Metaproterenol:
- acts on which receptors?
- uses?
- mostly beta-2 agonist; some beta 1
- treatment for acute asthma (like albuterol)
Albuterol:
- acts on which receptors?
- uses?
- mostly beta2 agonist; some beta1
- treatment of acute asthma
Salmeterol:
- acts on which receptors?
- uses?
- ->mostly Beta-2 agonist; some beta1
- ->long-term asthma treatment
Terbutaline:
- acts on which receptors?
- uses?
- ->mostly Beta-2 agonist; some beta-1
- ->Reduces premature uterine contractions (decreases uterine tone; so delays premature labor)
Ritodrine:
- acts on which receptors?
- uses?
- ->purely a Beta2 agonist
- used to reduce premature uterine contractions
Amphetamines:
- mechanism?
- uses?
–>indirect sympathomimetic; stimulates release of stored catecholamines
- Uses:
- Narcolepsy
- ADHD
- Obesity
Ephedrine:
- mechanism?
- uses?
–> indirect sympathomimetic; stimulates release of stored catecholamines
- Uses:
- nasal decongestion
- urinary incontinence
- hypotension
Cocaine:
- mechanism?
- effects?
–>indirect sympathomimetic; inhibits reuptake of catecholamines
- Effects:
- Vasoconstriction
- Local anesthesia
Clonidine:
- ->alpha-2-agonist
- decreases BP
- Uses:
- Hypertension, especially with renal disease (b/c does not decrease blood flow to kidney)
Methyldopa:
- ->alpha-2-agonist
- decreases BP
*Treats HTN, especially with renal disease; b/c doesn’t decrease blood flow to kidney
***can use methyldopa to treat HTN in pregnancy
Drug of choice for:
- anaphylactic shock?
- septic shock?
- cardiogenic shock?
- anaphylactic –> Epinephrine
- septic –> Norepinephrine
- cardiogenic –> Dobutamine
Phenoxybenzamine:
- mechanism?
- uses?
- toxicity?
Irreversible non-selective alpha-blocker
- Use:
- pheochromocytoma (give phenoxybenzamine before removing tumor)
- Toxicity:
- Orthostatic hypotension
- reflex tachycardia
Phentolamine:
- mechanism?
- use?
Reversible, non-selective alpha-blocker
- Use:
- give to pts on MAO inhibitors who eat tyrosine-containing foods
drugs that end with “-zosin”
–> alpha-1-selective blockers
prazosin, terazosin, doxazosin
Prazosin, Terazosin, Doxazosin:
- mechanism?
- use?
- toxicity?
alpha-1-blockers
- Uses:
- HTN
- urinary retention in BPH
- Toxicities:
- 1st dose orthostatic hypotension
- dizziness
- headache
Mirtzazpine:
- mechanism?
- use?
- toxicity?
- alpha-2-blocker
- Used in depression
- Toxicity:
- sedation
- elevates serum cholesterol
- increases appetite
alpha-1 and alpha-2 blockage: effects on vaculature?
alpha-1-blockers –> vasodilation
alpha-2-blockers –> vasoconstriction
Non-selective Beta-blockers:
block B1=B2 "Please Try Not to Be (beta) Picky" -Propranolol -Timolol -Nadalol -Pindolol
Beta-blockers that are partial Beta-agonists:
- Pindolol (non-selective Beta-blocker)
- Acebutolol (Beta-1-blocker)
Nonselective alpha and beta - blockers:
- Carvedilol
- Labetalol
Applications of Beta-Blockers:
- HTN: decrease CO, decrease renin secretion (Beta-receptor blockade on JGA cells)
- Angina pectoris: decrease HR and contractility; so, decrease O2 consumption of myocardium
- MI: decrease mortality
- SVT (Propranolol and Esmolol): decrease AV conduction velocity (class II antiarrhythmics)
- CHF: slows progression
- Glaucoma (Timolol, Betaxolol): decreases secretion of aqueous humor
Carvedilol
nonselective alpha AND beta blocker
–>vasodilatory
Labetalol
nonselective alpha AND beta blocker
–>vasodilatory
P-450 Inducers:
*Inducers–> increase metabolism rate; so decrease effect of other drugs
“Queen Barb Steals Phenphen and Refuses Greasy Carbs Chronically”
- Quinidine
- Barbiturates
- St John’s wort
- Phenytoin
- Rifampin
- Griseofulvin
- Carbamazepine
- Chronic alcohol
P-450 Inhibitors:
*Inhibitors–> slow metabolism rate; so increase toxicity of other drugs
“MAGIC RACKS”
- Macrolides
- Amiodarone
- Grapefruit juice
- Isoniazid
- Cimetidine
- Ritonavir
- Acute alcohol
- Ciprofloxacin
- Ketoconazole
- Sulfonamides
Sulfa Drugs:
“Popular FACTSSS”
- Probenecid (gout)
- Furosemide
- Acetazolamide
- Celecoxib
- Thiazides
- Sulfonamide antibiotics (ie SMX)
- Sulfasalazine (UC and Crohn’s)
- Sulonylureas (diabetes –> Glyburide)
Drugs that may cause Dilated Cardiomyopathy?
–> Doxorubicin, Daunorubicin (anti-cancer drugs; generate free radicals–> intercalate DNA –> breaks DNA –> decreased replication)
Drugs that may cause Agranulocytosis:
“Agranulocytosis Could Certainly Cause Pretty Major Damage)
- Clozapine (atypical antipsychotic)
- Carbamazepine (anti-epileptic)
- Colchicine (gout)
- Propylthioruracil (Graves)
- Methimazole (Graves)
- Dapsone (anti-bacterial, used to treat Mycobacterium leprae)
Drugs that may cause Aplastic Anemia:
- Chloramphenicol
- Benzenes
- NSAIDs
- Propylthiouracil
- Methimazole
Drugs that may cause Megaloblastic Anemia:
“having a Blast with PMS”
- Phenytoin
- Methotrexate
- Sulfa drugs
Drugs that may cause Pulmonary Fibrosis:
“BAB”
- Bleomycin (antitumor antibiotic; trtmnt for testicular cancer)
- Amiodarone (Class III antiarrhythmic)
- Busulfan (alkylating agent; trtmnt for CML and to prepare pt before BM transplant)
Drugs that may cause gynecomastia:
“Some Drugs Create Awesome Knockers”:
- Spirinolactone
- Digitalis
- Cimetidine
- Alcohol
- Ketoconazole
*Also, Estrogens!
Drugs that may cause Hypothyroidism:
- Lithium
- Amiodarone
- Sulfonamides
Drugs that may cause Gingivial Hyperplasia:
- Phenytoin
- Verapamil (CCB)
Drugs that may cause Photosensitivity:
“SAT for a Photo”:
- Sulfonamides
- Amiodarone
- Tetracycline
Drugs that may cause drug-induced lupus:
“SHIPP”
- Sulfas
- Hydralazine
- Isoniazid
- Procainamide
- Phenytoin
Drug that may cause tendonitis, tendon rupture, cartilage damage in kids:
–> Fluoroquinolones (FluoroquinoBONES!)
Drugs that may cause Nephrotoxicity + Ototoxicity:
- Cisplatin
- Carbaplatin
- Aminoglycosides
- Loop diuretics
- Vancomycin
Fomepizole:
–>Antidote for Methanol/Ethylene glycol (antifreeze) toxicity
Flumazenil
antidote for benzo toxicity
Protamine
antidote for Heparine toxicity
Aminocaproic acid
antidote for tPA, Streptokinase, Urokinase
Dimercaprol
Treatment for lead poisoning
antidote for mercury, arsenic, gold toxicity
Penicillamine
antidote for copper, arsenic, gold toxicity
Deferoxamine
antidote for iron toxicity
N-acetylcysteine:
antidote for acetaminophen toxicity (regenerates glutathione)
-AND-
mucolytic agent –> used to loosen mucous plugs in CF pts
Methylene blue
antidote for methemoglobin toxicity
Treatment for Cyanide poisoning?
First: Nitrites –> oxidize Hb to Met-Hb
Then: Thiosulfates –> renally excrete thiocyanate (thiosulfate bound to cyanide)
Drugs that may cause Hypothyroidism:
- Lithium
- Amiodarone
- Sulfonamides
Drugs that may cause Gingivial Hyperplasia:
- Phenytoin
- Verapamil (CCB)
Drugs that may cause Photosensitivity:
“SAT for a Photo”:
- Sulfonamides
- Amiodarone
- Tetracycline
Drugs that may cause drug-induced lupus:
“SHIPP”
- Sulfas
- Hydralazine
- Isoniazid
- Procainamide
- Phenytoin
Drug that may cause tendonitis, tendon rupture, cartilage damage in kids:
–> Fluoroquinolones (FluoroquinoBONES!)
Drugs that may cause Nephrotoxicity + Ototoxicity:
- Cisplatin
- Carbaplatin
- Aminoglycosides
- Loop diuretics
- Vancomycin
Fomepizole:
–>Antidote for Methanol/Ethylene glycol (antifreeze) toxicity
Flumazenil
antidote for benzo toxicity
Protamine
antidote for Heparine toxicity
Aminocaproic acid
antidote for tPA, Streptokinase, Urokinase
Dimercaprol
antidote for mercury, arsenic, gold toxicity
Penicillamine
antidote for copper, arsenic, gold toxicity
Deferoxamine
antidote for iron toxicity
N-acetylcysteine:
antidote for acetaminophen toxicity (regenerates glutathione)
-AND-
mucolytic agent –> used to loosen mucous plugs in CF pts
Methylene blue
antidote for methemoglobin toxicity
Treatment for Cyanide poisoning?
First: Nitrites –> oxidize Hb to Met-Hb
Then: Thiosulfates –> renally excrete thiocyanate (thiosulfate bound to cyanide)
