Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Pharm blk4- BDZ
Benzo, Sedatives, Hypnotics
| Question | Answer |
|---|---|
| what type of effects do BDZs produce, and are these effects dose-dependent | BDZs fall into group known as sedative-hypnotics that produce dose-dependent CNS depressant effects |
| what term is recently replacing the term "sedative" in sedative-hypnotic drugs, and why | anxiolytic - more accurately describes the effects - reduced activity, excitement, and calming effect |
| what are hypnotics | drugs that produce drowsiness and facilitate sleep |
| at what concentration do anxiolytic effects occur compared to hypnotic effects, in sedative/anxiolytic benzodiazepenes | anxiolytic effects occur at much lower concentration |
| what is the difference with hypnotic benzodiazepenes | concentrations at which anxiolytic and hypnotic effects occur are much closer |
| what type of effects occur with BDZs at even higher doses than hypnotic effects | some anesthetic actions |
| what part of the CNS do BDZs cause little depression of | medullary centers controlling respiration |
| what is the implication of this | BDZs are safe when used alone |
| what can occur when they are combined with other sedative/hypnotic drugs (i.e. alcohol) | fatal overdose |
| what drugs were said to be general CNS depressants (no "flattening out" of curve representing CNS effects as dose gets to high levels) | barbiturates - BDZs level off |
| how many times greater is the lethal dose compared to the typical therapeutic dose for BDZs | 1000x |
| what is the chemical structure of BDZs like | three ring structure - "benzodiazepene" refers to a benzene ring fused to a diazepine ring - all clinically relevant BDZs also contain a 5-aryl ring |
| are these drugs lipophilic, and what variation exists | lipophilic, but lipophilicity can vary by 50 fold |
| what is determined by the level of lipophilicity | rate of onset of action |
| which BDZ is the most lipophilic | diazepam (Valium) |
| what are the targets of BDZs | GABA-A receptors in the CNS (gamma subunit) |
| what is the structore of GABA-A receptors like | they are chloride channels |
| when GABA binds to the receptor, what does it cause to happen to chloride flow, and what is the result | chloride influx into cell, resulting in hyperpolarization and inhibition of cell's activity |
| what does the GABA-A receptor mediate | most of rapid, inhibitory transmission in the CNS |
| what is the other GABA receptor in the brain, and what effect do BDZs have on this receptor | GABA-B receptor - BDZs have no actions, and this is not a chloride channel |
| what other substance do BDZs require to function, and why | require GABA, as they enhance GABA binding to the receptor - BDZs are unable to directly open the channel themselves |
| what do BDZs cause by increasing GABA affinity for the receptor | increase in opening frequency of GABA-A receptor/ion channels and increased chloride influx |
| what do barbiturates, such as phenobarbital, cause to happen at the GABA-A receptor | prolonged duration of opening, rather than increased frequency caused by BDZs |
| what are six classes of disease or purposes that BDZs can be used for | 1) anxiety disorders; 2) insomnia; 3) muscle spasms; 4) epilepsy/seizures; 5) sedation for medical/surgical procedures; 6) ethanol withdrawal |
| what group should be given a lower dose of BDZ, and how much lower | patients over 65 - give 1/2 to 1/3 as much |
| what is the most potent benzodiazepene | triazolam (halcion) |
| what fraction of patients with pathological anxiety seek treatment | one third |
| in what ways can pathological anxiety occur (4) | 1) primary anxiety disorder; 2) secondary anxiety disorder; 3) response to acute stress; 4) with other psychiatric illness |
| for what common and serious medical problem was treatment of anxiety said to reduce risk of recurrence | MI |
| what commonly used drug often causes anxiety | caffeine |
| for what primary anxiety disorders are benodiazepenes first line treatments of (2) | 1) GAD (generalized anxiety disorder); 2) panic disorder |
| what other primary anxiety disorders were mentioned (3) | 1) phobic disorders; 2) OCD; 3) PTSD |
| for generalized anxiety disorder, what BDZ is most effective | all are equally effective in preventing anxiety |
| what is the most frequently prescribed anxiolytic in the US | alprazolam (Xanax) |
| what are three other most frequently prescribed BDZs | 1) lorazepam (Ativan); 2) diazepam (Valium); 3) clonazepam (Klonopin) |
| what are the primary differences among BDZs | pharmacokinetic properties |
| what can BDZs be classified according to | half life |
| do any have very long half lives | yes, many |
| what factors should be considered when prescribing a BDZ (4 - unrelated to illness BDZ is being prescribed for) | 1) half-life; 2) age of patient; 3) presence of liver disease; 4) presence of other drugs which compete for metabolism |
| what are criteria for diagnosis of panic disorder (2) | 1) at least two unexpected attacks; 2) persistent worry about having another panic attack |
| what is the term for panic attacks that are more likely to occur, but not always, in response to a certain situation | situationally predisposed |
| what else can panic attacks occur with or without | agoraphobia (fear of places from which escape may be difficult) |
| what are the FDA approved BDZs for treatment of panic disorder | 1) alprazolam; 2) clonazepam |
| what are times until onset like for these drugs | quick |
| what should be remembered about dosing for panic disorder, compared to GAD | higher doses of alprazolam are required for treatment of panic disorder compared to GAD |
| what is often msitaken for panic attack | PSVT (paroxysmal supraventricular tachycardia) |
| what classes of phobic disorders are there (2) | 1) simple phobia; 2) social phobia |
| what drug is used for simple phobia | drugs contraindicated |
| how is social phobia differentiated from agoraphobia | social phobia involves fear of humiliation, rather than fear of being unable to escape |
| what is the first line treatment for social phobia | SSRIs |
| what BDZs are used (2) but are second line treatments | 1) alprazolam; 2) clonazepam |
| what secondary problem has increased incidence in social phobics | alcoholism (25% increase) |
| what is contraindicated in these cases | BDZs |
| what type of benzodiazepene treatment course should be used for insomnia | between one to four weeks |
| what two undesirable problems develop | 1) tolerance to hypnotic effects; 2) physial dependence |
| what are desirable characteristics for hypnotic agents (3) | 1) rapid onset; 2) sustained action to facilitate sleep; 3) no residual action by morning |
| of the BDZs, which fits these criteria the best | triazolam (halcion) |
| what are the advantages of triazolam (2) | 1) short duration of action; 2) effective for people who have difficulty going to sleep |
| what are disadvantages of triazolam (4) | 1) tolerance develops within a few days; 2) early morning insomnia; 3) rebound insomnia upon discontinuation; 4) REM sleep rebound (blocks REM) |
| what problem arises from blocked REM | underlying anger gets expressed (violence) |
| what BDZ is useful for people with frequent wakening, and why | temazepam - peak effect is 2-3 hours after oral dose - intermediate rate of onset |
| what other advantage does temazepam have | no hepatic metabolism |
| what is a very long acting BDZ hypnotic that is used primarily for inpatients (half life is over 100 hours) | flurazepam |
| how long can it be effective | up to four weeks |
| what is one disadvantage | causes daytime sedation |
| how does it affect sleep (3) | 1) shortens time to onset; 2) decreases number of wakenings; 3) increases duration |
| what is another fast acting BDZ with a considerably long half life (39 hours) | quazepam |
| how potent are quazepam and flurazepam | low potency compared to other BDZ |
| what should be noted about quazepam and flurazepam's effects on sleep | these less potent and more slowly eliminated drugs continue to improve sleep even after discontinuation |
| what is an intermediate onset BDZ with a half life ranging from 8-31 hours | estazolam |
| who are BDZs contraindicated in for insomnia, and why | patients with obstructive sleep apnea - they decrease muscular tone in upper airway and exaggerate the impact of episodes of apnea |
| what are the muscle relaxant actions of BDZs due to, and where does this action take place | increase in presynaptic inhibition in the spinal cord |
| what BDZs are indicated for muscle spasms/spasticity (2) | 1) diazepam; 2) clonazepam |
| in what situations are these drugs used for spasms/spasticity (2) | 1) muscle injuries; 2) degenerative disorders |
| what degenerative disorders were mentioned (2) | 1) cerebral palsy; 2) MS |
| which of these drugs has an advantage, and what is that advantage | clonazepam has the advantage that it can be used to reduce spasticity at non-sedative doses |
| what BDZs are used for epilepsy (2) | 1) clonazepam; 2) clorazepate |
| what type of seizures is clonazepam used for | absence seizures |
| what problem can occur, and when does it | tolerance within 1-6 months |
| what type of seizures is clorazepate used for | partial seizures |
| in what strategy is clorazepate used | used with other anticonvulsants |
| what BDZs are used for acute seizures / status epilepticus (2) | 1) lorazepam; 2) diazepam |
| what line of treatment are these drugs | DOCs for status epilepticus |
| which stops seizures in the shortest time, how long does it take, and why | diazepam (IV) stops seizures in one minute (reaches brain in 10 seconds) because it is the most lipophilic |
| what is the half life of diazepam (IV) | 15 minutes |
| what should diazepam be followed by | phenytoin |
| how long does lorazepam (IV) take to stop seizures, and what is its half life | stops seizures in about five minutes, half life 12-15 hours |
| what BDZ is used for sedation prior to invasive procedures | midazolam |
| what effects does it produce that are useful for this purpose (3) | 1) conscious sedation; 2) muscle relaxation; 3) anterograde amnesia |
| what doses are required for anterograde amnesia | preanesthetic doses |
| what doses are required to cause general anesthesia | does not cause general anesthesia by itself |
| what serious problem has midazolam caused during use for conscious sedation, and in what patient groups (2) | death due to respiratory arrest in: 1) patients premedicated with narcotics; 2) patients with COPD |
| what problem occurs frequently upon withdrawal of chronic alcohol that can be treated with BDZs | seizures |
| what BDZs are used for the management of acute effects of alcohol withdrawal (4) | 1) chlordiazepoxide; 2) diazepam; 3) clorazepate; 4) oxazepam |
| how is dosing determined | doses are titrated so that only a tremor is present during withdrawal |
| what dose usually needs to be given, and why | because of cross-tolerance at GABA-A receptor, you need to give max therapeutic dose of BDZ |
| how well are almost all BDZs absorbed, and from where | quickly, from the gut |
| what is the exception, and what is different about its absorption | clorazepate - it is decarboxylated in gastric juice to an active metabolite which is completely absorbed |
| what is the implication of the high lipid solubility of BDZs | taken up rapidly into brain (and other highly perfused organs) then redistributed to tissues less well perfused |
| what BDZs have fastest redistribution | highest lipid solubility |
| how important is redistribution from brain to other tissues in terminating CNS effects | can be as important as metabolism in terminating CNS effects |
| do BDZs cross the placenta, and are they secreted into breast milk | yes, yes |
| what transformation, and where, is necessary for elimination of BDZs | hepatic metabolism to water-soluble compounds |
| what important compounds are many BDZs metabolized to | active metabolites |
| what is the half time of the active metabolite like, compared to parent compound | longer |
| what is the implication of the longer half life of active metabolite | long half-lives can cause cumulative effects with multiple doses |
| what was said to be true about metabolism of those with short half lives (one of two things) | 1) don't have active metabolites; 2) active metabolites are quickly eliminated |
| what class of BDZs usually don't have active metabolites | hypnotic BDZs |
| what exception must we know | flurazepam is a hypnotic with active metabolites and a long half life |
| what is an ultra-short acting BDZ | midazolam (half life 1-2 hours) |
| what is a short acting BDZ | halcion |
| what are four long-acting BDZs mentioned | 1) chlordiazepoxide; 2) diazepam; 3) flurazepam; 4) quazepam |
| how many phases does hepatic metabolism of most BDZs occur in | three |
| what is phase one, and what does it result in | initial oxidation step results in N-desalkylated active metabolites |
| what is phase two, and what does it result in | hydroxylation at R3 yields another active metabolite |
| what is phase three, and what does it result in | conjugation of hydroxyl compounds with glucuronic acid yeilding inactive metabolites which are excreted in the urine |
| what is the fastest, second-fastest, and slowest reaction | phase 1 (fastest), phase 3, phase 2 (slowest) |
| what phase(s) are often bypassed in drugs with shorter half lives | phase 1, 2 |
| in what patients are phase 1 and 2 reactions often reduced in (2) | 1) elderly; 2) liver disease |
| what related drugs were said to be able to increase their own metabolism, and how | barbiturates increase their own metabolism by inducing the hepatic microsomal enzymes |
| what three substances were mentioned to reduce or slow down phase 1 and 2 reactions (3) | 1) cimetidine; 2) oral contraceptives; 3) grapefruit juice |
| what BDZs have no active metabolites (3) | 1) lorazepam; 2) oxazepam; 3) temazepam |
| who would these be good options for (2) | 1) elderly; 2) liver disease |
| what effects of BDZ effects does tolerance develop more for (3) | 1) hypnotic; 2) muscle relaxant; 3) anti-convulsant (not anxiolytic effects) |
| when does physical dependence occur with BDZ treatment | if BDZs are given for long periods |
| which BDZs are physical dependence more likely with (what characteristics - 2) | 1) shorter acting; 2) more potent |
| what four were mentioned to be shorter acting and more potent | 1) alprazolam; 2) klonazepam; 3) lorazepam; 4) triazolam |
| what are symptoms of withdrawal from BDZs like | similar to those for which the BDZ was originally prescribed |
| what group of BDZs do not produce as severe withdrawal symptoms | those with longer half lives |
| what is indicated for people on BDZs for prolonged periods who are to stop taking them | gradual withdrawal |
| what are the two most common adverse effects | 1) drowsiness; 2) confusion |
| what are three other adverse effects | 1) motor incoordination; 2) cognitive impairment; 3) anterograde amnesia |
| when is anterograde particularly common | when BDZs are used with alcohol |
| how should doses for elderly be adjusted, and what BDZs are more appropriate | doses should be one third to a half of those typically prescribed, and BDZs with a shorter half life are more appropriate |
| what other problems can BDZs cause in the elderly | increased risk of falling (even with those drugs that have shorter half lives) |
| what are BDZs used during pregnancy linked to | cleft palate |
| besides pregnancy, when should women always avoid BDZs | when nursing |
| what drugs have an additive effect with BDZs (2) | 1) alcohol; 2) other sedative hypnotics |
| what can these cause when combined | respiratory depression |
| in what diseases are BDZs contraindicated (3) | 1) liver disease; 2) COPD; 3) obstructive sleep apnea |
| what is the problem in liver disease | effects are potentiated because of decreased metabolism |
| what BDZs are more appropriate for patients with liver disease | those without active metabolites |
| what drug was said to cause problems in patients with COPD (asthma, chronic bronchitis, and emphysema) and what problem does it casue | effects of midazolam on respiration are exaggerated in these patients |
| why are BDZs bad in sleep apnea | muscle relaxant effects aggravates disroders - use with caution in people who snore a lot, too |
| what non-benzodiazepene is useful for anxiety | buspirone (Buspar) |
| what is the MOA of buspirone | partial agonist at 5HT1A receptors (also has affinity for DA receptors, possibly a mixed agonist/antagonist) |
| what undesirable properties of BDZs is it missing (4) | 1) physical dependence; 2) withdrawal; 3) no cross-tolerance; 4) no interaction with alcohol |
| what else is a major difference between buspirone and BDZs | buspirone has a slow onset of action (2-4 weeks) |
| who is buspirone good for (2) | 1) elderly; 2) patients with substance abuse problems |
| what main non-benzodiazepene is good for insomnia | zolpidem (Ambien) |
| what is onset and half life like | quick onset (within 1-2 hours), half life of 2.5 hours |
| how do the effects of zolpidem compare to BDZs (what effects of BDZs does and doesn't it have) | it has selective hypnotic effect, but minimal anxiolytic, anticonvulsant, and muscle relaxant effects |
| who should doses be adjusted for, and how | should be adjusted down for elderly |
| what are side effects (4) | 1) dizziness; 2) headache; 3) confusion; 4) sleepiness |
| what drug can zolpidem interact with | alcohol |
| what is a similar option to zolpidem | zaleplon (Sonata) |
Created by:
mcafej02
Popular Science sets