PHARMACOLOGY part 1 Flashcards
the following suffix is indicative of what corresponding drug class?
“caine”
local anesthetic
the following suffix is indicative of what corresponding drug class?
“coxib”
cyclooxygenase (COX)-2 inhibitors
the following suffix is indicative of what corresponding drug class?
“dipine”
dihydropyridine calcium channel blockers
the following suffix is indicative of what corresponding drug class?
“dronate”
bisphosphonates
the following suffix is indicative of what corresponding drug class?
“fungin”
glucan synthesis inhibitor, antifungal
the following suffix is indicative of what corresponding drug class?
“gliptin”
dipeptidyl peptidase-4 inhibitor drug for type 2 diabetes
the following suffix is indicative of what corresponding drug class?
“glitazone”
peroxisome proliferator activated receptor gamma activator for type 2 diabetes
the following suffix is indicative of what corresponding drug class?
“grel”
P2Y12 adenosine diphosphate receptor inhibitor in platelets
the following suffix is indicative of what corresponding drug class?
“olol”
beta adrenergic receptor blockers
the following suffix is indicative of what corresponding drug class?
“ilol” or “alol”
beta adrenergic receptor blocker that also blocks alpha1 adrenergic receptors
the following suffix is indicative of what corresponding drug class?
“mab”
monoclonal antibodies
the following suffix is indicative of what corresponding drug class?
“onium” or “urium”
quaternary ammonium compounds, usually competitive, peripherally acting skeletal muscle relaxers
the following suffix is indicative of what corresponding drug class?
“osin”
alpha1 adrenergic receptor blockers
the following suffix is indicative of what corresponding drug class?
“oxacin”
fluoroquinolone antibacterial
the following suffix is indicative of what corresponding drug class?
“parin”
heparin or low-molecular-weight heparin
the following suffix is indicative of what corresponding drug class?
“prazole”
proton pump inhibitor
the following suffix is indicative of what corresponding drug class?
“penem”
carbapenem beta lactam antibacterial
the following suffix is indicative of what corresponding drug class?
“pril” or “prilat”
angiotensin-converting enzyme (ACE) inhibitors
the following suffix is indicative of what corresponding drug class?
“sartan”
angiotensin II receptor blockers
the following suffix is indicative of what corresponding drug class?
“statin”
3-hydroxy-3-methylglutaryl coenzyme A (HMG-COA) reductase inhibitor antilipid drugs
the following suffix is indicative of what corresponding drug class?
“teplase”
tissue plasminogen activator drug
the following suffix is indicative of what corresponding drug class?
“ triptan”
serotonin 5-HT agonist antimigraine drugs
___ is the maximal effect of a drug
intrinsic acvitity
___ is the effect of a drug as a function of level of binding to its receptor
efficacy
___ is a term that refers to the attractiveness of a drug to its receptor
- affinity
- measured by the dissociation constant (Kd)
- lower Kd corresponds to higher affinity
___ is the response to a drug over a given range of concentrations
potency
___ is the study of what the body does to the drug
pharmacokinetics
if a drug is made active by metabolism, it is called a ___
prodrug
what are examples of phase I reactions?
oxidation, reduction, and hydrolysis
what are examples of phase II reactions?
conjugation, in which a chemical substituent is added to the drug
most metabolism of drugs occurs in which organ?
liver
excretion of drugs usually occurs in what organ?
the kidney, especially for more soluble drugs
___ refers to the elimination of a constant amount of drug eliminated regardless of dose
zero-order elimination kinetics
___ is the most common type of elimination kinetics, in which a constant percentage of remaining drug is eliminated
first-order elimination kinetics
between zero-order and first-order kinetics, the risk of accumulation is usually greater for which one?
zero-order kinetics
the most common form of drug-drug interaction is one drug affecting the ___ of another drug
metabolism
describe the drug-drug interaction between the following drugs commonly used in dentistry:
- aspirin
- anticoagulants
increased bleeding tendency
___ describes an adverse drug reaction that is due to a genetic change usually involving a change in enzyme activity
idiosyncratic reaction
what is the idiosyncratic response to the following genetic abnormality and involved drug:
- altered muscle calcium homeostasis
- volatile inhalation anesthetics, succinylcholine
malignant hyperthermia
what is the idiosyncratic response to the following genetic abnormality and involved drug:
- prolonged Q-T interval
- some antipsychotics and antiarrhythmics
torsades de pointes
all nerve pathways originate from the CNS; the sympathetics from ___ outflow, and the parasympathetics from ___ outflow
- thoracolumbar
- cranial-sacral
the adrenal medulla secretes which two hormones?
- epinephrine and norepinephrine
- there is no ganglion here, but the ACh receptors are ganglionic nicotinic in type
what is the sympathetic response of salivary glands? what about the parasympathetic response?
- sympathetic response is a viscous secretion, amylase secretion
- parasympathetic response is a more profuse, watery secretion
what is the main use for the following adrenergic agonists?
- epinephrine
- norepinephrine
- epinephrine: reverse anaphylaxis, vasoconstriction, bronchodilation
- norepinephrine: vasoconstriction
what are alpha-1 blockers used to for?
to treat hypertension, heart failure, and benign prostate hypertrophy
what are the adverse effects of alpha-1 blockers?
hypotension (especially first-dose effect), fluid retention, dry mouth, and nasal stuffiness
which adrenergic neuron blockers indirectly reduce granule content of NE but increase it in the cytoplasmic pool of adrenergic neurons?
MAO inhibitors, such as pargyline and tranylcypromine
which medication is used in dentistry to reverse soft tissue anesthesia more quickly after procedures involving a local anesthetic with a vasoconstrictor?
- phentolamine (oraverse)
- nonselective alpha-adrenergic receptor blocker (alpha 1 and 2)
beta blockers increase the ___ response to epinephrine, but reduce the ___ resulting from epinephrine
- vasoconstrictor response
- tachycardia
what is the use for the following cholinergic receptor agonists:
- pilocarpine
- cevimeline
- pilocarpine: treat glaucoma and stimulate salivary flow
- cevimeline: stimulate salivary flow
what is the use for the following cholinesterase inhibitors:
- physostigmine
- pyridostigmine
- physostigmine: glaucoma, antidote for atripine
- pyridostigmine: treat myasthenia gravis
what is the use for the following cholinesterase inhibitors:
- tacrine
- donepezil
both: treat alzheimer’s disease
what is the use for the following cholinesterase inhibitors:
- galantamine
- rivastigmine
both: treat alzheimer’s disease
what is the use for the following cholinesterase inhibitors:
- sarin
- soman
both: nerve gas
___ is used to reactivate acetylcholinesterase after irreversible inhibition by an organophosphate (echothiophate, isoflurophate, sarin, soman)
pralidoxime
what are the uses for the following antimuscarinic drugs?
- atropine
- scopolamine
- atropine: prototype, to reduce salivary flow, for antivagal effect during surgery, antidote for physostigmine
- scopolamine: prototype, for motion sickness
what is the dose of atropine for reducing salivary flow?
oral administration is 0.5mg (adult dose)
what are the contraindications for antimuscarinic drugs?
- narrow-angle glaucoma
- prostate hypertrophy
- paralytic ileus
- tachycardia
what are skeletal neuromuscular blockers used for?
during surgery for relaxing skeletal muscle, for endotracheal intubation, and for treatment of tetanus
what are examples of curare-type neuromuscular junction blockers?
d-tubocurarine, pancuronium, atracurium, vecuronium, pipecuronium, rocuronium, doxacurium, mivacurium
which skeletal neuromuscular junction blocker relaxes skeletal muscle without blocking nicotinic receptors?
dantrolene
botulinum toxin A (botox) is a skeletal neuromuscular junction blocker that prevents the release of ___ from neurons
ACh
what are the uses of botulinum toxin A?
- ophthalmology to relax extraocular muscles
- muscle dystonias
- remove wrinkles
which local anesthetics are esters?
procaine, tetracaine, and cocaine
which local anesthetics are amides?
lidocaine, mepivacaine, bupivacaine, prilocaine, and dibucaine
where are ester local anesthetics metabolized?
plasma, by esterases
where are amide local anesthetics metabolized?
liber
which class of drugs has the most consistency in structure?
- local anesthetics
- they are either esters or amides, and differ only in their structure in the intermediate chain (either ester or amide) that connects the aromatic group to the secondary or tertiary amino terminus
what are the toxic reactions to local anesthetics due to?
either high systemic levels of LA in general (cardiovascular collapse due to myocardial depression, hypotensive shock), or to a specific agent (such as prilocaine, which causes methemoglobinemia)
what is the mechanism of action of local anesthetics?
they prevent the generation of nerve impulses by interfering with sodium transport into the neuron
in terms of absorption of local anesthetics, which form penetrates tissue membranes?
- the non-ionized (free base) form
- once inside the neuron, only the ionized form is effective
describe the pH of inflamed tissue and how that affects absorption of local anesthetics
inflamed tissue has a lower than normal pH, which decreases the amount of non-ionized form available to penetrate
which local anesthetics have a short duration of action?
procaine
which local anesthetics have a moderate duration of action?
prilocaine, mepivacaine, and lidocaine
which local anesthetics have a long duration of action?
bupivacaine, tetracaine, and etidocaine
initially, local anesthetics inhibit ___ neurons, which results in CNS ___, which can proceed to ___. at higher doses, they inhibit both ___ and ___ neurons, leading to a generalized state of CNS ___, which can result in ___ and ___
- central inhibitory
- stimulation
- convulsions
- inhibitory and excitatory
- depression
- respiratory depression and death
in toxic doses, local anesthetics depress ___ and ___
membrane excitability and conduction velocity
which is the only local anesthetic that predictably produces vasoconstriction?
cocaine
which is the only local anesthetic to block the reuptake of NE into adrenergic neurons, and thus potentiate the NE that has been released from nerve endings?
cocaine
describe onset of action of local anesthetics in terms of nerve size
- the theory states that there is a size dependent critical length of anesthetic exposure necessary to block a given nerve
- small fibers will be blocked first because the anesthetic concentration needed for the critical length in a small fiber will be reached faster than the critical length in a larger fiber
- you need to block 3 nodes of ranvier, and they are farther apart in larger fibers than they are in smaller fibers
what is the AHA limit of local anesthetic for a patient who is cardiovascularly compromised?
0.04mg, compared to 0.2mg in the healthy patient
of penicillin V and penicillin G, which is more sensitive to acid degradation in the stomach and thus is usually injected rather than taken orally?
penicillin G
which penicillin has the best gram-negative spectrum?
ampicillin
which drugs are cross-allergenic with penicillin?
- most usually asked about ones are cephalosporins and ampicillin
- erythromycin is not cross-allergenic
which penicillin is useful against penicillinase-producing bugs such as staphylococcus?
dicloxacillin
which penicillin is specific for pseudomonas infections?
an extended spectrum such as carbenicillin
which combination of agents should be used prophylactically for patients with heart valve to prevent bacterial endocarditis?
- ampicillin and gentamycin (combinations are no longer used)
- keflex 2g (4x500mg), PO 1 hr before treatment. number of tablets dispensed depends on number of appointments
what is the first choice prophylactic regimen for subacute bacterial endocarditis if a patient is not allergic to penicillin?
- amoxicillin 2g (4x500mg), PO 1 hr before treatment. number of tablets dispensed depends on number of appointments
- children dose is 50mg/kg 1 hr before appointment
what is the first choice prophylactic regimen for subacute bacterial endocarditis if a patient is allergic to penicillin?
-clindamycin 600mg (4x150mg), PO 1 hr before appointment. number of tablets dispensed depends on number of appointments
what is the non-oral prophylactic regimen for subacute bacterial endocarditis?
- ampicillin IV/IM 2g, 1/2 hr before appointment (children: 50mg/kg)
- clindamycin (for PCN-allergic) 600mg IV 1/2 hr before appointment (children: 20mg/kg)
for the following list of cardiovascular conditions, which requires prophylaxis?
prosthetic valves, previous endocarditis, cardiac pacemakers, rheumatic fever without valvular dysfunction, mitral valve prolapse without valvular regurgitation, pulmonary shunts
-required: proshetic valves, previous endocarditis, and pulmonary shunts
for the following list of dental procedures, which requires prophylaxis in a patient with a risk of infective endocarditis or prosthetic joint infection?
extractions, restorative procedures, intracanal endodontic treatment, periodontal surgery, implants, taking of impressions
-required: extractions, periodontal surgery, implants (rule of thumb is anything that includes gingival manipulation or mucosal incision
what is the prescription regimen for treating an infection?
- penicillin VK 250-500mg, dispense 30, take 2 tablets at once, then 1 tab every 6 hrs until gone (7 days) some sources do not indicate loading dose, so dispense 28, take 1 Q6H until gone (kids less than 12 yrs: 20-50mg/kg QID)
- clindamycin 150-300mg, dispense 21, take 1 capsule every 8 hrs until gone (7 days), (kids: 8-12mg/kg TID or QID)
- amoxicillin 500mg, dispense 21, take 1 capsule every 8 hrs until gone (7 days), (kids under 20kg: 20-40 mg/kg TID)
what is the mechanism of action of penicillins?
- bactericidal
- kill rapidly growing cells by inhibiting cell wall synthesis
what is the mechanism of action of tetracycline?
- bacteriostatic
- limit population growth (do not kill bugs) by interfering with protein synthesis on bacterial ribosomes
what is the mechanism of action of nystatin?
- antifungal
- binds to ergosterol in the fungal cell wall to weaken the wall
what is the mechanism of action of sulfonamides?
- bacteriostatic
- compete with PABA in folic acid synthesis, thus resulting in folic acid deficiency
what are symptoms seen during allergic reactions to penicillins?
dermatitis, stomatitis, bronchoconstriction, and cardiovascular collapse
what agent produces GI upset and pseudomembranous colitis?
clindamycin
which agents are most likely or least likely to cause superinfection?
- most likely: broad spectrum agents such as tetracyclines
- least likely: narrow spectrum agents such as penicillin G
aplastic anemia is associated with which agent?
chloramphenicol
toxic levels of tetracycline are associated with what?
liver damage or hepatotoxicity, especially in pregnant patients with history of renal disease
which agent is associated with allergic cholestatic hepatitis?
erythromycin estolate
what is the drug-drug interaction for tetracycline and penicillin?
- cidal-static interaction
- cancel each other out due to opposing mechanisms of action
what is the drug-drug interaction for probenacid and penicillin
probenacid alters the rate of renal clearance of penicillin
what is the drug-drug interaction for tetracyclines and antacids?
effectiveness of tetracyclines is reduced by concurrent ingestion of antacids or dairy products
what is the drug-drug interaction for broad spectrum antibiotics and coumarin anticoagulants?
broad spectrum antibiotics enhance the action of coumarin anticoagulants (vitamin K antagonists, include coumadin/warfarin) because of the reduction of vitamin K sources
what is the drug-drug interaction for antibiotics such as ampicillin and oral contraceptives?
antibiotics such as ampicillin decrease the effectiveness of oral contraceptives due to suppression of normal GI flora involved in the recycling of active steroids from bile conjugates, leading to more rapid excretion of the steroids from the body
what is the drug-drug interaction for macrolides such as erythromycin and drugs such as seldane and digoxin?
macrolides inhibit the metabolism of seldane and digoxin
what is acyclovir used for?
an antiviral used for various forms of herpes
what are fluconazole and ketoconazole used for?
systemic-acting antifungals useful for treating candidiasis
cephalosporins (like cephalexin) are chemically related to which agent?
- penicillins
- therefore, cephalosporins share the relatively nontoxic nature of penicillins
___ is considered an “extended spectrum” form of penicillin, and is not penicillinase resistant
ampicillin
what antibiotic is useful for treating bone infections such as osteomyelitis?
clindamycin
what antibiotic is able to achieve a higher concentration in gingival fluid than in serum?
tetracycline
which antibiotic can damage the eighth nerve, affecting both balance and hearing?
streptomycin
T or F:
other than allergic reactions, penicillins are extremely safe, with no effect on the liver
true
___ is an antifungal agent that produces such adverse side effects as nephrotoxicity and hypokalemia, but not liver toxicity
amphotericin B
is gentamicin broad or narrow spectrum?
broad
is tetracycline broad or narrow spectrum?
broad
is penicillin G broad or narrow spectrum?
narrow
is streptomycin broad or narrow spectrum?
broad
is chloramphenicol broad or narrow spectrum?
broad
tetracyclines are broad spectrum antibiotics effective against which bacteria?
gram positive and gram negative cocci and bacilli
compare the spectrum of activity of clindamycin, erythromycin, vancomycin, and tetracycline
clindamycin has a spectrum of activity similar to erythromycin and vancomycin, which is less than that of the tetracyclines, mainly affecting gram positive microogranisms
compare 1st generation cephalosporins to 3rd generation cephalosporins
1st generation are effective against both gram negative and gram positive organisms, but 3rd generation ones have increased activity against gram negative but greatly decreased activity against gram positive microorganisms
T or F:
tetracyclines are the drug of choice for prophylaxis against infective endocarditis
- false
- this is due to streptococcal infection (15-20% of group A streptococci are resistant to tetracyclines, but none are resistant to penicillin or erythromycin
why will patients with renal disease show high blood levels of penicillin?
- penicillin is metabolized in the liver, but it rapidly disappears from the blood due to rapid clearance by the kidneys
- 90% is excreted by tubular secretion
- similarly, probenicid (a uricosuric agent which tends to enhance the excretion of uric acid by reducing renal tubular transport mechanisms) reduces the renal clearance of penicillins
what is the erythromycin-seldane potentially lethal interaction?
- erythromycin blocks the metabolism of seldane to its antihistamine metabolite (it stays unmetabolized and causes cardiac arrythmias)
- erythromycin decreases the metabolism of many useful drugs, including digoxin
which classes of drugs are used to treat hypertension?
- duretics (furosemide)
- beta blockers (propranolol, or cardioselective beta blocker metoprolol or atenolol)
- alpha-1 blocker (prazosin)
- centrally acting adrenergic drugs (methyldopa or clonidine)
- neuronal blockers (guanethidine, reserved for severe hypertension)
- angiotensin converting enzyme inhibitors (captopril, lisinopril)
which drugs are used to treat angina?
nitroglycerin, sometimes propranolol, calcium channel blockers like verapamil
which drugs are used to treat ventricular arrhythmias?
lidocaine
which drugs are used to reverse digitalis induced arrhythmias?
phenytoin
which drug is used to treat supraventricular tachyarrhythmias and atrial fibrillation?
quinidine
which drug is used to treat supraventricular tachyarrhythmias, paroxymal tachycardia, and atrial fibrillation?
verapamil
which drug is used to treat atrial fibrillation and paroxysmal tachycardia?
digitalis (verapamil will treat these as well, in addition to supraventricular tachyarrhythmias)
which type of arrhythmia is propranolol used to treat?
paroxysmal tachycardia
which drugs are used to treat congestive heart failure?
- glycosides such as digitalis and digoxin
- ACE inhibitors such as captopril
which cardiac problem is described as an irregularity in heart beat?
arrhythmia
what is the mechanism of action of antiarrhythmics?
- type 1A agents such as quinidine: acts by increasing the refractory period of cardiac muscle
- type 1B agents such as lidocaine decrease cardiac excitability
- when digitalis is used for atrial fibrillation, it acts by decreasing the rate of A-V conduction
which cardiac problem is described as insufficient oxygen to meet demands of the myocardium?
angina
what is the mechanism of action of antiangina drugs?
- nitroglycerin increases oxygen supply to the heart by a direct vasodilatory action on the smooth muscle in coronary arteries
- propranolol reduces oxygen demand by preventing chronotropic responses to endogenous epinephrine, emotions, and exercise
- calcium channel blockers decrease oxygen demand by reducing afterload by reducing peripheral resistance via vasodilation
most antihypertensive drugs have the ultimate effect of reducing ___ via ___
peripheral resistance via vasodilation
what is the mechanism of action of ACE inhibitors used as antihypertensives?
- captopril blocks the enzyme which converts angiotensin I to angiotensin II
- the latter is a potent vasoconstrictor (administration of angiotensin will result in an elevation of blood pressure)
what is the mechanism of action of the following adrenergic agents:
prazosin and methyldopa
- prazosin: selevtive alpha-1 blocker, inhibits binding of nerve induced release of NE, resulting in vasodilation
- methyldopa: acts centrally as a false neurotransmitter stimulating alpha receptors to reduce sympathetic outflow, resulting in vasodilation
what is the mechanism of action of the following adrenergic agents:
clonidine, propranolol, and metoprolol
- clonidine: selective agonist stimulates alpha-2 receptors in the CNS to reduce sympathetic outflow to peripheral vessels, resulting in vasodilation
- propranolol: nonselective beta blocker reduces cardiac output and inhibits renin secretion
- metoprolol: selective beta-1 blocker, reduces cardiac output
what is the mechanism of action of diuretics? what are 3 examples?
- decrease the renal absorption of sodium, thus resulting in fluid loss and a reduction in blood volume
- thiazides (chlorothiazide), high-ceiling or loop acting (furosemide), and potassium sparing (spironolactone)
what is the mechanism of action of congestive heart failure drugs (cardiac glycosides like digitalis or digitoxin)?
- positive inotropic effect increases the force of contraction of the myocardium
- this is achieved by inhibition of Na+, K+ ATPase leading to increased calcium influx
- digitalis therapy reduces the compensatory changes that are associated with congestive heart failure such as increased heart size, rate, edema, etc
how does hydralazine reduce hypertension?
has a direct action on vascular smooth muscle to cause vasodilation
aside from blocking beta-1 receptors, blocking of ___ release is thought to be the other mechanism whereby beta-blockers alter hypertension
renin
which loop or high-ceiling diuretic is associated with deafness?
ethacrynic acid
which diuretic causes potassium loss (hypokalemia)?
chlorothiazide
what is the mechanism of action of the analgesic effects of NSAIDs?
aspirin inhibits the synthesis of prostaglandins
what is the mechanism of action of the antipyretic (reduce fever) effects of NSAIDs?
aspirin inhibits prostaglandin synthesis in the hypothalamic temperature regulation center
what is the mechanism of action of the bleeding time effects of NSAIDs?
inhibits synthesis of thromboxane A2, preventing platelet synthesis
what are the therapeutic effects of aspirin (NSAID)?
pain relief, antipyretic (anti-fever) effects, antirheumatic, and anti-inflammatory effects
what are the adverse or toxic effects of aspirin (NSAID)?
occult bleeding from the GI tract, tinnitus, nausea and vomiting, acid-base disturbance or metabolic acidosis, decreased tubular reabsorption of uric acid, salicylism, delirium, and hyperventilation
what is the difference between aspirin and acetaminophen?
acetaminophen lacks anti-inflammatory activity, is hepatotoxic, and does not cause GI upset
what is the difference between aspirin and other anti-inflammatories like prednisone, hydrocortisone, and triamcinolone?
prednisode, hydrocortisone, and triamcinolone are steroids and do not act primarily on prostaglandin inhibition
what is the difference between aspirin and ibuprofen?
ibuprofen causes much less GI irritation
which NSAID has a longer half-life than aspirin, acetaminophen, and ibuprofen?
diflunisal (dolobid)
what are the toxic effects of acetaminophen?
- liver toxicity/necrosis, especially when combined with alcohol or taken in excess of 4g/day
- renal necrosis as well
what is the drug of choice for a feverish child?
acetaminophen
why should aspirin be avoided for a feverish child?
increased risk of reye’s syndrome
what is the mechanism of action of heparin?
inhibits thrombin and prevents formation of the fibrin network
what is the mechanism of action of coumarin?
inhibits GI absorption of vitamin K and prevents synthesis of blood clotting factors
what is the mechanism of action of corticosteroids, like triamcinolone?
inhibits phospholipase A2
NSAIDs cause gastric irritation and bleeding due to their effects on ___ synthesis in the ___
prostaglandin synthesis in the mucosal wall of the gut
what is phenytoin?
an anticonvulsant, with the major side effect of gingival hyperplasia
which NSAID causes so much GI irritation that its use is limited in humans?
indomethacin
what are the effects aspirin has on body temperature?
it only lowers body temperature in the presence of a fever (no effect on body temp in the non-feverish patient)
suppression of the cough reflex is a major therapeutic use of which drugs?
narcotic opiates such as codeine
what are two common mixed-agonist-antagonists (MAA)?
pentazocine and nalbuphine
___ is an antagonist used to treat overdose
naloxone
___ is used in detoxification of morphine addicts
methadone
what are the effects of morphine?
produces respiratory depression, euphoria, sedation, dysphoria, analgesia, constipation, and urinary retention
what does overdose of morphine cause?
coma, miosis, and respiratory depression
in morphine overdose, what is the mechanism of respiratory depression?
loss of sensitivity of the medullary respiratory center to carbon dioxide
describe the use of narcotics for the treatment of diarrhea
-OTC narcotics in the form of paregoric (tincture of opium) and lomotil (loperamide) act on receptors in the gut to produce constipation
what are the only class of drugs that suppress the cough reflex?
opioids (codeine and meperidine - codeine is better)
what are the two hallmark opioid overdose effects?
miosis (pinpoint pupils) and respiratory depression
which of the following are agonists only, and which are antagonists only?
codeine, methadone, naloxone, meperidine
- agonists: codeine, methadone, and meperidine
- antagonists: naloxone
why is withdrawal of methadone less severe than with morphine?
because methadone has a much longer half-life
what are 3 competitive muscarinic receptor blockers that are sometimes used to control salivary secretions?
atropine, scopolamine, and propantheline
what is the mechanism of action of atropine?
blocks vagal reflexive control of heart rate, resulting in tachycardia
describe physostigmine and neostigmine
- both are reversible anticholinesterases sometimes used in the treatment of xerostomia
- physostigmine acts both centrally and peripherally
- neostigmine only peripherally, but also has some direct ACh-like activity at the neuromuscular junction, in addition to prolonging the activity of endogenous ACh
what are 2 direct acting cholinergic agonists sometimes used for xerostomia?
pilocarpine and methacholine
___ and ___ irreversibly inhibit cholinesterase
organophosphates and insecticides
___ is an enzyme regenerator used in organophosphate toxicity
pralidoxime
___ is a depolarizing neuromuscular junction blocker, subject to rapid inactivation by plasma pseudocholinesterase; it is used to prevent laryngospasm
succinylcholine
___ is a non-depolarizing neuromuscular junction blocker
d-tubocurarine
___ and ___ are ganglionic blockers that produce orthostatic hypertension
mecamylamine and hexamethonium
what are cholinergic crisis symptoms? how is it treated?
- bradycardia, lacrimation, salivation, voluntary muscle weakness, diarrhea, and bronchoconstriction
- treat with atropine
what are the signs of scopolamine overdose? how is it treated?
- disorientation, confusion, hallucinations, burning dry mouth, and hyperthermia
- treat with physostigmine
how does atropine cause tachycardia?
blocks vagal reflexive control of heart rate