Neuro - Pharmacology Flashcards
Which two -agonists are used to treat glaucoma?
Epinephrine and brimonidine
How do β-agonists treat glaucoma?
They decrease aqueous humor synthesis
Which β-agonist is contraindicated for closed-angle glaucoma?
Epinephrine
Which β-blockers are used to treat glaucoma?
Timolol, betaxolol, carteolol
By what mechanism do β-blockers treat glaucoma?
They decrease aqueous humor secretion
How does acetazolamide treat glaucoma?
It decreases aqueous humor secretion by inhibiting carbonic anhydrase
Which four cholinomimetics are used to treat glaucoma?
Pilocarpine, carbachol, physostigmine, echothiophate
By what mechanism do cholinomimetics treat glaucoma?
They increase outflow of aqueous humor, contract the ciliary muscle, and open the trabecular meshwork
Which drug is used for glaucoma in emergencies?
Pilocarpine
Which prostaglandin increases the outflow of aqueous humor in glaucoma? Of which prostaglandin is it an analogue?
Latanoprost; prostaglandin F2
A patient;s new glaucoma drug is causing browning of the iris. What is she taking?
Latanoprost
Morphine, fentanyl, codeine, heroin, methadone, meperidine, and dextromethorphan are in which category of drugs?
Opioid analgesics
What is the mechanism of action of opioid analgesics?
They act as agonists at the mu, delta, and kappa opioid receptors to modulate synaptic transmission
Match the following substances with the opioid receptor (mu/delta/kappa) that they bind most avidly: morphine, dynorphin, enkephalin.
Dynorphin is avidly bound to the kappa receptor, enkephalin is avidly bound to the delta receptor, and morphine is avidly bound to the mu receptor
Which opioid agonist is used for cough suppression?
Dextromethorphan
Which two opioid agonists are used to alleviate diarrhea?
Loperamide and diphenoxylate
Which opioid analgesic is used for maintenance programs for heroin addicts?
Methadone
What changes in neurotransmitter release result from opioid receptor agonists?
They inhibit release of acetylcholine, norepinephrine, serotonin, glutamate, and substance P
A patient well-known to the emergency department presents with respiratory depression, constipation, and miosis. What is the most likely cause of her condition?
Opioid toxicity
Despite requiring increasing doses for recreational use, which two adverse effects of opioid use will patients not develop tolerance to?
Miosis and constipation
Which two drugs are used to treat opioid toxicity?
Naloxone or naltrexone (opioid receptor antagonists)
Butorphanol acts a partial _____ (agonist/antagonist) at opioid _____ (mu/kappa) receptors, and an _____ (agonist/antagonist) at _____ (kappa/delta) receptors.
Agonist; mu; agonist; kappa
What is the toxicity of butorphanol?
Withdrawal if a patient is on a full opioid agonist, due to its partial agonist activity
What is the benefit of butorphanol over other opioid analgesics?
Butorphanol causes less respiratory depression than full agonists
Which analgesic drug is a weak opioid agonist and inhibitor of serotonin and norepinephrine uptake?
Tramadol
What is the toxic effect of tramadol?
Decreases seizure threshold
What is the clinical use of tramadol?
Chronic pain
Which types of seizures are treated with phenytoin? What is its mechanism of action?
Simple and complex partial seizures, tonic-clonic seizures, and status epilepticus; inactivates sodium channels
Which types of seizures are treated with carbamazepine? What is its mechanism of action?
Simple and complex partial seizures and tonic-clonic generalized seizures; inactivates sodium channels
Which types of seizures are treated with lamotrigine? What is its mechanism of action?
Simple and complex partial seizures and tonic-clonic generalized seizures; inactivates sodium channels
Which types of seizures are treated with gabapentin? What is its mechanism of action?
Simple and complex partial seizures and tonic-clonic generalized seizures; inactivates calcium channels
Which epilepsy drug is the first-line agent used to treat pregnant patients?
Phenobarbital
Which types of seizures are treated with phenobarbital? What is its mechanism of action?
Simple and complex partial seizures and tonic-clonic generalized seizures; increases GABAAaction
What is the first-line agent used to prevent seizures in patients with eclampsia?
Magnesium sulfate
Which types of seizures are treated with valproic acid? What is its mechanism of action?
Simple and complex partial seizures and tonic-clonic and absence generalized seizures; inactivates sodium channels, increases GABA concentration
If magnesium sulfate fails to prevent seizures in a patient with eclampsia, what class of drugs could also be used?
Benzodiazepines
Which types of seizures are treated with ethosuximide? What is its mechanism of action?
Absence generalized seizures; blocks thalamic T-type calcium channels
Which types of seizures are treated with benzodiazepines? What is the mechanism of action?
Status epilepticus; increase the action of GABAA
Which types of seizures are treated with tiagabine? What is its mechanism of action?
Simple and complex partial seizures; inhibits GABA reuptake
Which types of seizures are treated with vigabatrin? What is its mechanism of action?
Simple and complex partial seizures; it irreversibly inhibits GABA transaminase, thus increasing GABA concentration
Which types of seizures are treated with levetiracetam? What is its mechanism of action?
Simple and complex partial seizures and tonic-clonic generalized seizures; its mechanism is unknown, but it may modulate GABA and glutamate release
Which two blood dyscrasias are associated with carbamazepine toxicity?
Agranulocytosis and aplastic anemia
Which two epilepsy drugs may predispose individuals who are taking them to Stevens-Johnson syndrome?
Ethosuximide and lamotrigine
Which antiepileptic drug may cause sedation, tolerance, and dependence in addition to inducing cytochrome P450 enzymes?
Phenobarbital
What epilepsy drug may cause lupus-like syndrome and gingival hyperplasia?
Phenytoin
A patient with epilepsy presents with hirsutism, megaloblastic anemia, ataxia, and gingival hyperplasia. What drug may this person be taking to help treat the epilepsy?
Phenytoin
What are the adverse effects of carbamazepine use?
Diplopia, ataxia, blood dyscrasias, liver toxicity, teratogenesis, and the induction of cytochrome P450
Name the toxicities of ethosuximide; use the mnemonic, EFGH.
Ethosuximide = Fatigue, GI distress, Headache
Acute hepatotoxicity is associated with which antiepileptic drug?
Valproic acid
Women of childbearing age who are using which two antiepileptic drugs should also be using birth control because of the teratogenic risks?
Valproic acid, which causes neural tube defects, and carbamazepine
Which antiepileptic drug is associated with kidney stones and weight loss?
Topiramate
Name two adverse effects of gabapentin.
Sedation and ataxia
What is Stevens-Johnson syndrome?
A disorder characterized by a prodrome of malaise and fever followed by rapid onset of erythematous and purpuric macules found on oral, ocular, and genital surfaces that eventually progress to epidermal necrosis and the sloughing of skin
What is the mechanism of action of phenytoin?
Phenytoin creates a use-dependent blockade of sodium channels and inhibits glutamate release from excitatory presynaptic neurons
What is the teratogenic effect of phenytoin use during pregnancy?
Fetal hydantoin syndrome
Which antiepileptic drug is primarily used to treat tonic-clonic seizures and is also a class IB antiarrhythmic agent?
Phenytoin
A patient presents with nystagmus, ataxia, diplopia, and sedation after starting an antiepileptic drug for tonic-clonic seizures. What medication was the patient most likely started on?
Phenytoin
Phenobarbital, pentobarbital, thiopental, and secobarbital are members of which class of drugs?
Barbiturates
True or False? Dependence is a major adverse effect of barbiturates.
True
What is the mechanism of action of barbiturates?
Barbiturates facilitate GABAAaction by increasing the duration of chloride channel opening, thereby decreasing neuron firing (remember: BarbiDURATes increase duration)
What class of medications commonly used to treat anxiety is contraindicated for patients with porphyria?
Barbiturates
What is the treatment for barbiturate overdose?
Assisted respiration and maintenance of blood pressure until the drug is metabolized
What are the clinical uses of barbiturates?
Barbiturates are commonly used as sedatives for treating anxiety, seizures, and insomnia, and for the induction of anesthesia
What is the effect of combining barbiturates with alcohol?
Barbiturates have an additive central nervous system depression effect when combined with alcohol
What is the effect of barbiturates on cytochrome P450?
Barbiturates induce cytochrome P450 enzymes
Diazepam, lorazepam, triazolam, temazepam, oxazepam, midazolam, chlordiazepoxide, and alprazolam are members of what class of drugs?
Benzodiazepines
Which class of drugs used for symptoms of alcohol withdrawal (delirium tremens) has an additive central nervous system depression effect with alcohol and may result in dependence?
Benzodiazepines
Compared with barbiturates, benzodiazepines carry a(n) _____ (decreased/increased) risk of respiratory depression and coma.
Decreased
What is the mechanism of action of benzodiazepines?
Benzodiazepines facilitate GABAAaction by increasing the frequency of chloride channel opening (remember: FREnzodiazepines increase FREquency)
Most benzodiazepines have a _____ (short/long) half-life and ______ (active/inactive) metabolites.
Long; active
With which drug should benzodiazepine overdose be treated? What is its mechanism of action?
Flumazenil; it is a competitive antagonist of GABA receptors
What are the clinical uses of benzodiazepines?
Benzodiazepines are used to treat anxiety, spasticity, status epilepticus, night terrors, and sleepwalking
Which are the short-acting benzodiazepines?
Triazolam, Oxazepam, Midazolam (remember: TOMThumb is SHORT)
Which benzodiazepines have the higher addictive potential, short or long acting?
Short acting
General anesthetics that act on the central nervous system must be _____ (lipid/water) -soluble or actively transported across the blood-brain barrier.
Lipid
Nitrous oxide has _____ (high/low) blood and lipid solubility and thus _____ (fast/slow) induction.
Low; fast
Nitrous oxide has _____ (high/low) blood and lipid solubility and thus _____ (fast/slow) induction.
Low; fast
Halothane has high lipid and blood solubility; thus, it has _____ (high/low) potency and _____ (fast/slow) induction.
High; slow
When discussing general anesthetics, the higher the lipid solubility, the _____ (higher/lower) the potency.
Higher
Anesthetic drugs with _____ (low/high) solubility in the blood have rapid induction and reduced recovery times.
Low
When discussing general anesthetics, what does the acronym MAC stand for and indicate? How does it relate to potency?
Minimal alveolar concentration at which 50% of the population is anesthetized; the lower the MAC, the more potent the anesthetic
Name four inhaled anesthetics.
Halothane, enflurane, isoflurane, and sevoflurane
What are four common adverse effects of inhaled anesthetics?
Myocardial depression, respiratory depression, emesis, and increased cerebral blood flow
Match the anesthetic to the type of toxicity: halothane, methoxyflurane, enflurane – nephrotoxicity, proconvulsant, hepatotoxicity.
Halothane causes hepatotoxicity; methoxyflurane causes nephrotoxicity; enflurane is a proconvulsant
Which class of drugs can cause malignant hyperthermia, myocardial depression, and a decrease in cerebral metabolic demand?
Inhaled anesthetics
Inhaled anesthetics may cause a(n) _____ (decrease/increase) in cerebral blood flow.
Increase
Which barbiturate is commonly used for the induction of anesthesia and short surgical procedures?
Thiopental
What is the most common drug used for anesthesia during endoscopy?
Midazolam
What are two common adverse effects of midazolam?
Amnesia and respiratory depression
_____, which is a phencyclidine (PCP) analog, acts as a dissociative anesthetic.
Ketamine
What are the effects of ketamine and thiopental on cerebral blood flow?
Ketamine increases cerebral blood flow whereas thiopental decreases it
What are three common adverse effects of ketamine?
Disorientation, hallucinations, and bad dreams
Which two opiates are commonly used with other agents during general anesthesia?
Morphine and fentanyl
Which intravenous lipid-based anesthetic, used for rapid anesthesia induction, results in less postoperative nausea than thiopental?
Propofol
What is the only commonly used anesthesia induction agent that does not lower blood pressure?
Ketamine
What is the mechanism of action of propofol?
Propofol potentiates GABAA
How does the mnemonic B.B. King on OPIATES PROPOses FOOLishly help you remember the classes and drugs involved in intravenous anesthesia?
Barbiturates, Benzodiazepines, Ketamine, OPIATES, Propofol
What is the mechanism of action of ketamine?
It blocks NMDA receptors
Name three local anesthetics with an ester group.
Procaine, cocaine, and tetracaine
Local anesthetics block _____ channels by binding to specific receptors on the _____ (inner/outer) portion of the channel.
Sodium; inner
Local anesthetics penetrate infected tissue _____ (less/more) efficiently because of the ______ (decreased/increased) acidity in the tissue.
Less; increased
A nerve blockade has the greatest effect on nerves that are _____ (myelinated/unmyelinated) and _____ (large/small). _____ (Myelination/Size) predominates over _____ (myelination/size).
Myelinated; small; Size; myelination; therefore, small myelinated nerves are anesthetized first, followed by small unmyelinated fibers and then large fibers
List the order in which the following sensation is lost during nerve blockade from first to last: pressure, pain, touch, and temperature.
Pain, temperature, touch, and pressure
Name three local anesthetics with an amide group.
Lidocaine, mepivacaine, and bupivacaine (remember: amIdes have 2 I;s in name)
Local anesthetics preferentially bind to ______ (activated/inactivated) sodium channels, so they are most effective in ______ (rapidly/slowly) firing neurons.
Activated; rapidly
Which drug is commonly mixed with local anesthesia (except for cocaine) to enhance the local anesthesia action, to decrease bleeding, and to decrease systemic concentration?
Epinephrine; it acts through local vasoconstriction, which leads to less dilution of the anesthetic agent
What amide, which is used in local anesthesia, may cause severe cardiovascular toxicity?
Bupivacaine
What uncommonly used local anesthetic is a commonly abused street drug that may cause cardiac arrhythmias?
Cocaine
Accidentally injecting local anesthetics such as lidocaine into a vein may cause what adverse event?
Cardiac arrhythmia
Succinylcholine is a _____ (depolarizing/nondepolarizing) neuromuscular blocking agent.
Depolarizing
Neuromuscular blocking drugs that are commonly used for muscle paralysis during surgery or mechanical ventilation are selective for motor _____ receptors.
Nicotinic
What is the antidote to phase I (prolonged depolarization) action of succinylcholine?
There is no antidote
Phase I depolarization in neuromuscular blockade is potentiated by _____ inhibitors.
Cholinesterase
Name six nondepolarizing neuromuscular blocking drugs.
Tubocurarine, atracurium, mivacurium, pancuronium, vecuronium, and rocuronium
Nondepolarizing neuromuscular blocking drugs compete with _____ for receptors.
Acetylcholine
What is the antidote for a nondepolarizing neuromuscular blocking drug?
Neostigmine or edrophonium
Use of succinylcholine may cause what two electrolyte abnormalities?
Hyperkalemia and hypercalcemia
What is the antidote for phase II (repolarized but blocked) action of succinylcholine?
Neostigmine or other cholinesterase inhibitors
Which drug is used to treat malignant hyperthermia and neuroleptic malignant syndrome?
Dantrolene
Dantrolene can treat malignant hyperthermia via what mechanism of action?
By preventing the release of calcium from the sarcoplasmic reticulum of skeletal muscle
The use of which two drugs concomitantly may result in malignant hyperthermia in a patient who is genetically susceptible?
Inhalation anesthetics with succinylcholine
Bromocriptine is an agonist of which neurotransmitter?
Dopamine
Which selective monoamine oxidase type B inhibitor prevents the breakdown of dopamine in the central nervous system?
Selegiline
For which parkinsonian symptoms is benztropine effective?
Tremor and rigidity, but not bradykinesia (remember: decrease your tremor before you drive your Mercedes-BENZ)
Amantadine may _____ (decrease/increase) dopamine release.
Increase
Name two catechol-O-methyltransferase inhibitors that prevent the breakdown of L-dopa in the central nervous system.
Entacapone and tolcapone
Patients with parkinsonism have excess activity of what neurotransmitter?
Acetylcholine
What class of medication is used to treat an essential or familial tremor?
β-Blockers
Which five drugs/classes are used to treat Parkinson;s disease? Use the mnemonic, BALSA.
Bromocriptine, Amantadine, Levodopa (with carbidopa), Selegiline (and catechol-O-methyltransferase inhibitors), Antimuscarinics
What drug used to treat Parkinson;s disease is also used as an antiviral agent against influenza A and rubella?
Amantadine
Amantadine toxicity is characterized by what symptom?
Ataxia
Which medication used to treat Parkinson;s disease crosses the blood-brain barrier, where it is then converted into dopamine by dopa decarboxylase in the central nervous system?
L-dopa
What effect may L-dopa have on the heart?
Arrhythmias
Which medication is a peripheral decarboxylase inhibitor that is given with L-dopa to increase its effective concentration?
Carbidopa
Selegiline may _____ (increase/decrease) the adverse effects of L-dopa in patients with parkinsonian conditions.
Increase
Name two drugs that are approved to treat Alzheimer;s disease.
Memantine and donepezil
To which class of drugs does donepezil belong?
Acetylcholinesterase inhibitors
What three side effects are associated with donepezil?
Nausea, dizziness, insomnia
Which drug, used for Alzheimer;s disease, acts as a NMDA receptor antagonist?
Memantine
What are the side effects of memantine?
Dizziness, confusion, hallucinations
Memantine helps prevent what calcium-mediated process in Alzheimer;s disease?
Excitotoxicity of neurons
Huntington;s disease is characterized by _____ (increased/decreased) dopamine, _____ (increased/decreased) GABA, and _____ (increased/decreased) acetylcholine activity.
Increased; decreased; decreased
Name two amine-depleting drugs used to treat Huntington;s disease.
Reserpine and tetrabenazine
Which dopamine receptor antagonist can be used to treat Huntington;s disease?
Haloperidol
What is the mechanism of action of sumatriptan?
It is a serotonin receptor 5-HT1B/1Dagonist that inhibits the trigeminal nerve and reduces vasoactive peptide release
What adverse effects can result from sumatriptan use?
Coronary vasospasm and mild tingling
Sumatriptan is used to treat what conditions?
Migraines and cluster headaches
Sumatriptan is contraindicated in patients with what two conditions due to its effect of coronary vasospasm?
Coronary artery disease and Prinzmetal;s angina