Flashcards in Pharmacology Deck (65):
Pt treated for psychosis develops generalized muscle stiffness and shaking of hand -- treatment?
caused by antipsychotics that block D2 receptors
- antimuscarinic agents like benztropine
Levodopa and dopamine agonists like bromocriptine are CONTRAINDICATED because they can precipitate psychosis
Antibiotic that can precipitate serotonin syndrome?
Commonly used drugs that can precipitate serotonin syndrome in pts using other serotonergic drugs?
Atypical antidepressant that treats insomnia and is associated with priapism?
also side effect of postural hypotension (strong alpha1 blockade in addition to 5-HT2 blockade)
Treatment for tonic-clonic seizures and bipolar disorder?
What class of drugs is used to treat motion sickness? Side effects?
Antimuscarinics (like scopolamine) and antihistaminics
Antimuscarinic side effects: blurry vision, dry mouth, palpitations, urinary retention, constipation
How to treat symptoms of pt with pronounced negative symptoms of schizophrenia?
Atypical antipsychotics treat both positive and negative symptoms (vs. typical antipsychotics that work only on positive symptoms)
It's ATYPICAL for OLd CLOSets to QUIETly RISPER from A to Z.
Feature of methadone that makes it an effective substitution for heroin addiction treatment?
slow kinetics means there is no "rush" and prolonged effects with tapering effect is used to suppress withdrawal symptoms in heroin dependent patients
Schizophrenia pt with retinal deposits? with corneal deposits?
reTinal deposits - Thioridazine
Corneal deposits - Chlorpromazine
both are antipsychotics (block D2 receptors)
What is naloxone and what is it used for?
opioid receptor antagonist
used to treat opioid toxicity/overdose
What is used for benzodiazepine toxicity?
Flumazenil (competitive antagonist at the GABA benzodiazepine receptor)
Dilated pupils, yawning, rhinorrhea, lacrimation, diarrhea, nausea/vomiting may be due to withdrawal from what type of drugs?
Opioids (e.g., heroin, morphine, etc.)
Mechanism of action of ethosuximide? Use?
blocks thalamic T-type Ca2+ channels
used for absence seizures
What is the mechanism of action for phenytoin, carbamazepine, and valproic acid?
all increase Na+ channel inactivation (reducing ability of channels to recover from inactivation)
Valproic acid also:
- increases GABA concentration by inhibiting GABA transaminase
- blocks T-type Ca2+ channels so can be used in absence seizures
What are the COMT inhibitors?
prevent L-dopa degradation to increase availability to the CNS/brain
Which opioid side effects are most resistant to tolerance?
Miosis/pinpoint pupils and constipation
What is lamotrigine? Side effects?
blocks voltage-gated Na+ channels
Stevens-Johnson syndrome: malaise and fever prodrome followed by rapid onset of erythematous/purpuric macules (oral, ocular, genital) that progresses to epidermal necrosis and sloughing
also seen in carbamazepine and ethosuximide (other antiepileptics)
Farmer with sweating, wheezing, bradycardia, constricted pupils? Treatment? What symptoms are addressed by each treatment?
Organophosphate poisoning / cholinesterase inhibitor poisoning
atropine (competitive muscarinic inhibitor) -- ONLY treats the side effects due to muscarinic receptor stimulation (DUMBELSS except for the Excitation of muscle/muscle paralysis)
pralidoxime -- regenerates AChE if given early enough and thus reverses BOTH muscarinic and nicotinic effects
Which sympathetic receptors increase insulin release? decrease insulin release?
beta-receptors stimulate insulin secretion (beta2)
alpha-receptors inhibit insulin secretion (alpha2)
Pt treated for MI with prolonged expirations and wheezing -- explanation?
beta blockers -- inhibit NT interaction with receptor in adrenergic synapses
beta1 blockade = decreased heart rate
beta2 blockade = bronchoconstriction and wheezing
BETA2 BLOCKADE EXACERBATES COPD AND ASTHMA
What is the mechanism of beta blocker use in glaucoma?
decreases secretion of aqueous humor from the ciliary epithelium (mediated by beta2 receptors)
timolol and other nonselective beta blockers
What are the high potency antipsychotics? What are the low potency antipsychotics? What are the major side effects of each?
High potency: "Try to Fly High"
Low potency: "Cheating Thieves are low"
High potency antipsychotics = more likely to cause extrapyramidal symptoms
Low potency antipsychotics = more likely to cause non-neurologic side effects (sedation, anticholinergic, orthostatic hypotension)
What is minimal alveolar concentration (MAC) for an inhaled anesthetic? What is the relationship between MAC and potency?
percentage of anesthetic in the inspired gas mixture that renders 50% of pts unresponsive to painful stimuli (ED50)
MAC and potency: inverse relationship
lower the MAC, the more potent the anesthetic
What are the symptoms of serotonin syndrome? What is the precursor AA for serotonin?
hyperthermia, sweating, confusion, myoclonus, muscle rigidity, cardiovascular collapse
What does adding carbidopa to levadopa treatment do?
Carbidopa inhibits peripheral conversion of levadopa to dopamine
reduces most of the peripheral side effects of levodopa (including nausea/vomiting due to CTZ in area postrema, which is OUTSIDE the BBB)
behavioral/central changes can worsen with carbidopa thought, because more dopamine available to brain
Treatment for narcolepsy?
modafinil (non-amphetamine stimulant)
nighttime sodium oxybate (GHB)
What psychotropic medication has a side effect of hypothyroidism?
also causes nephrogenic diabetes insipidus (polyuria)
What is the treatment for alcohol withdrawal and DTs?
benzodiazepines (diazepam, chlordiazepoxide)
Barbiturates like thiopental have rapid recovery from anesthesia (used for induction and short procedures) -- what is the mechanism of recovery?
Effect terminated by rapid redistribution of drug into tissue and fat (NOT due to metabolism of drug)
What is the treatment for serotonin syndrome?
(5-HT receptor antagonist)
an antihistamine with anti-serotonergic properties
What is the treatment for benzodiazepine overdose?
What is the treatment for opioid overdose?
pure opioid receptor antagonist
binds all receptor types but greatest affinity for mu receptors
What is a common side effect of SSRI use?
also GI upset and potential for serotonin syndrome
much better side effect profile vs. TCAs
What is the effect of beta2 stimulation on uterine tone?
beta2 receptors lead to uterine relaxation
used in obstetrics to defer premature labor (ritodrine and terbutaline)
Alternative to SSRIs for pts that want an agent without sexual side effects? Other use?
also used for smoking cessation
Pt with atypical, severe depression comes in after a pizza dinner with high BP and HR? Mechanism?
hypertensive crisis due to tyramine-containing food consumption (cheese) while on an MAO inhibitor
- MAOI prevents MAO degradation of monoamines like NE, 5HT, DA)
- Tyramine acts as a NE releaser (mobile pool)
leads to hypertensive crisis (alpha1 and beta1 activation)
Treatment for status epilepticus?
administer a benzodizepine (lorazepam or diazepam) for ACUTE treatment
load with phenytoin for PROPHYLAXIS
if seizures continue, add barbiturate; if still persist, intubate and anesthetize
Periodic sudden-onset arrhythmic jerking movements, usually early in the morning (aggravated by sleep deprivation), not preceded by urge to make movement, does not lose consciousness -- what kind of seizure? Treatment of choice?
type of generalized seizure but typically no loss of consciousness
Drug of choice is valproic acid.
Side effects of H1 blockers like diphenhydramine?
antimuscarinic (pupillary dilation, cycloplegia, dry mouth, urinary retention, constipation)
anti-alpha-adrenergic (hypotension, postural dizziness)
Pt with berry aneurysm and blood in subarachnoid space -- 3days later, has weakness in arm and leg. What drug could have prevented these sequelae?
calcium channel blocker like nimodipine
decreases morbidity and mortality due to cerebral vasospasm when used as a preventative agent following subarachnoid hemorrhage
What are pramipexole and ropinirole?
(bromocriptine = ergot; pramipexole and ropinirole = non-ergot/preferred)
used to treat Parkinson disease
Describe the action of Selegiline and COMT inhibitors.
selective MAO-B inhibitor
inhibits CENTRAL dopamine degradation (MAO-B present in the brain)
COMT inhibitors (entacapone, tolcapone)
decrease breakdown of L-dopa in the PERIPHERY
thus increase the amount of L-dopa in the brain
What is akathisia? Side effect of what drugs?
inner restlessness and inability to sit or stand in one position
extrapyramidal side effect of antipsychotics (particularly the high potency drugs -- Trifluoperazine, Fluphenazine, Haloperidol)
Drug of choice for trigeminal neuralgia? Side effects?
- aplastic anemia
- P450 inducer
- Stevens-Johnson syndrome
Pt with BP of 180/100 and HR of 120 after major surgery with fever, muscle rigidity? Treatment
Treatment: dantrolene (prevents Ca2+ release from SR of skeletal muscle)
What precipitates malignant hypertension? Mechanism and treatment?
hypersensitivity of skeletal muscles to inhalation anesthestics (esp. halothane) and succinylcholine (muscle relaxant)
autosomal dominant mutation in ryanodine receptor on SR
leads to huge increase of Ca2+ in cell, huge contractile response
Treatment: dantrolene (acts on ryanodine receptor to prevent further release of Ca2+ into cytoplasm of muscle fibers)
Agent for atropine toxicity?
tertiary amine, so reverses BOTH peripheral and CNS symptoms by crossing BBB
Buproprion side effects?
- seizures (especially in pre-existing epilepsy, bulimia, and/or anorexia)
- stimulant effects (tachy, insomnia)
NO sexual side effects
Pt with seizure disorder, mental illness and gingival hyperplasia? Main side effects?
- mainly affects cerebellum and vestibular system (ataxia and nystagmus)
- gingival hyperplasia, hirsutism
- decreased folate absorption and megaloblastic anemia
- P450 induction
- tetratogenic (fetal hydantoin syndrome)
Gingival hyperplasia and hirsutism?
How can a muscarinic agonist mediate vasodilation?
walls of peripheral blood vessels do NOT have cholinergic innervation
but muscarinic receptors are present on the endothelial surface
binding of muscarinic agonists to these receptors leads to NO release and vascular smooth muscle relaxation
Pt after general anesthesia develops elevated AST, ALT, bilirubin? Findings?
Toxicity of inhaled anesthetics -- highly lethal, fulminant hepatitis that causes rapid and massive hepatic necrosis/atrophy (shrunken liver)
Epilepsy drug with generalized lymphadenopathy? Other side effects?
- hirsutism, coarsening of facial features
- gingival hyperplasia
- megaloblastic anemia (decreased folate absorption)
- SLE-like syndrome
- P450 induction
- teratogen (fetal hydantoin syndrome)
What are the P450 inducers?
CHRONIC ALCOHOLic MOna STeals PHEN-PHEN and Never Refuses Greasy Carbs
St. John's wort
What is Haloperidol? Uses and major toxicities? Treatment of toxicities?
antipsychotic / neuroleptic
blocks D2 receptors (Gi coupled) to increase cAMP
used in schizophrenia, also in Huntington's (to decrease Dopamine)
Extrapyramidal symptoms (high potency antipsychotic)
Neuroleptic malignant syndrome
- extreme general rigidity
- autonomic instability
- altered mental status
Treatment: dantrolene and D2 agonists (bromocriptine, etc.)
Treatment: discontinue and switch to atypical
Best means of close contacts prophylaxis for N. meningitidis?
Anti-epileptic with risk for aplastic anemia? Other major side effects?
- hepatotoxicity (monitor LFTs)
- increased ADH secretion (SIADH)
- P450 induction
- Stevens-Johnson syndrome
Drug of choice for Listeria?
not covered by cephalosporins
Major side effects of clozapine?
agranulocytosis and seizures
What is essential tremor? What is the treatment?
action tremor, worsened by holding posture/limb position
improved by EtOH
Treatment: nonspecific beta blocker (PROPANOLOL)
First-line and second-line for absence seizures? EEG pattern?
Ethosuximide, then valproate
EEG pattern: generalized 3.0 Hz spike-wave pattern complexes superimposed on normal background activity
Child with absence seizures and tonic-clonic seizures -- treatment?
drug of choice
(Ethosuxamide is not effects against generalized tonic-clonic, only absence)
What is thiopental? How is it eliminated and where does it go?
Barbiturate used in general anesthesia (SHORT-ACTING)
- short surgical procedures
rapid plasma decay of thiopental NOT metabolism but redistribution to other tissues:
- skeletal muscles
- adipose tissue
What is atypical depression? Treatment?
main characteristic: mood reactivity (improved mood in response to positive events, although very brief)
- leaden fatigue (heavy limbs)
- increased sleep and appetite
- rejection sensitivity (overly sensitive to slight criticism)
Treatment: MAOIs, SSRIs