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105 Cards in this Set
- Front
- Back
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What is the generic name of Xanax?
What drug list is it on? What does it do? |
- Alprazolam
- GABA receptor modulation -USED TO TREAT ANXIETY Duration: Medium 10-20 hours |
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What is the generic name of BUSPAR?
What drug list is it on? What does it do? |
- buspirone
- GABA receptor modulation - |
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What is the generic name of LIBRIUM?
What drug list is it on? What does it do? |
- chlordiazepoxide
- GABA receptor modulation -USED TO TREAT ANXIETY & ETHANOL/OPIATE PHYSICAL DEPENDENCE Duration: Long 1-3 days |
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What is the generic name of KLONOPIN?
What drug list is it on? What does it do? |
- clonazepam
- GABA receptor modulation - USED TO TREAT SEIZURE/EPILEPSY Duration: Extra-long Weeks |
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What is the generic name of VALIUM?
What drug list is it on? What does it do? |
- diazepam
- GABA receptor modulation - USED TO TREAT SEIZURE/EPILEPSY Duration: Long 1-3 days |
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What is the generic name of ROMAZICON?
What drug list is it on? What does it do? |
- flumazenil
- GABA receptor modulation -The effect of all benzodiazepines can be reversed by flumazenil. Flumazenil, which is injected intravenously, is an antagonist at the benzodiazepine binding site of the GABAA receptor. It effectively and rapidly reduces benzodiazepine effects at the cellular level and it therefore effectively and rapidly reverses the (cellular and) behavioral effects of benzodiazepines. |
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What is the generic name of ATIVAN
What drug list is it on? What does it do? |
- lorazepam
- GABA receptor modulation - USED TO TREAT ANXIETY Duration: Medium 10-20 hours |
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What is the generic name of VERSED?
What drug list is it on? What does it do? |
- midazolam
- GABA receptor modulation - Duration: Short 3-8 hours |
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What is the generic name of SERAX?
What drug list is it on? What does it do? |
- oxazepam
- GABA receptor modulation - Duration: Short 3-8 hours |
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What is the generic name of NEMBUTAL?
What drug list is it on? What does it do? |
- pentobarbital
- GABA receptor modulation - USED TO TREAT SEIZURE/EPILEPSY - medium (6-8 hour) duration of action sedative, hypnotic |
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What is the generic name of LUMINAL?
What drug list is it on? What does it do? |
- phenobarbital
- GABA receptor modulation - long (12-18 hour) duration of action sedative, hypnotic, anti-epileptic - Phenobarbital is less rapidly absorbed across the wall of the gastrointestinal tract and enters the brain from the plasma less rapidly. CAN NOT be given orally (the only one) |
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What is the generic name of SECONAL?
What drug list is it on? What does it do? |
- secobarbital
- GABA receptor modulation - medium (6-8 hour) duration of action sedative, hypnotic |
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What is the generic name of PENTOTHAL?
What drug list is it on? What does it do? |
- thiopental
- GABA receptor modulation - short (30 minutes) duration of action general anesthetic |
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What is the generic name of HALCION
What drug list is it on? What does it do? |
- triazolam
- GABA receptor modulation - USED TO TREAT INSOMNIA - used as general anesthetics Duration: Short 3-8 hours |
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What is the generic name of AMBIEN?
What drug list is it on? What does it do? |
- zolpidem
- GABA receptor modulation -Zolpidem: A Non Benzodiazepine-Barbiturate Hypnotic Zolpidem is only used to treat insomnia. Theoretically zolpidem could be used for other purposes for which benzodiazepines are used but there is no advantage to such use partly because of its short duration of action. Zolpidem, a drug introduces in the late 1990's, is chemically similar to but is not actually a benzodiazepine. However, this drug does have high affinity for the benzodiazepine binding site of the GABAA receptor and mimics the effect of benzodiazepines. The duration of action of zolpidem is relatively short (a few hours) and zolpidem has been reported to be less likely to produce dependence or tolerance during chronic use. |
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What is the generic name of Restoril?
What drug list is it on? What does it do? |
_ Temazepam
_ GABA receptor modulation - USED TO TREAT INSOMNIA - used as general anesthetics |
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Which barbiturates and benzodiazepines are used as general anesthetics?
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Triazolam, Temazepam
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What is GABA?
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a neurotransmitter throughout the central nervous system (CNS).
GABAergic neurons form short connections between neurons using other transmitters within all regions of the CNS. |
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GABA synthesizing- and releasing- neurons are not found where?
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in distinct tracts or pathways (as is the case for instance for dopaminergic neurons) connecting different parts of the CNS. Instead, GABAergic neurons form short connections between neurons using other transmitters within all regions of the CNS.
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Consistent with the fact that there are GABAergic neurons throughout the CNS, GABA receptors are expressed by?
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all neurons in the CNS.
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What are the type types of GABA receptors?
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GABAA receptors, which are the real topic of this section and will be described in detail in subsequent subsections,and GABAB receptors, which are differentially distributed compared to, and functionally and pharmacologically different to GABAA receptors.
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It’s important to recognize that GABAergic neurons and GABAergic receptors are present only in?
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the CNS
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GABA is not a neurotransmitter in?
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the peripheral nervous system.
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GABAA receptors have four important sites to which drugs can bind with high affinity.
What are they? |
GABA binding site
Barbiturate binding site Benzodiazepine binding site Ethanol binding site |
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Each of these sites is essentially a receptor but is usually described as a binding site.
The term GABAA receptor is used to refer? |
to the complete receptor unit (with all its binding sites and functional effector parts) as is the case here (or occasionally to refer only to the GABA binding site itself).
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What is the GABA binding site?
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this is the site to which GABA binds and thus activates the receptor. There are other (synthetic) agonists which bind to and activate the receptor for this binding site; there are also synthetic antagonists which bind to but do not activate the receptor but which will prevent binding of agonists to this binding site. These agonists and antagonists are useful research tools but have not been found to be useful clinically. The effects of binding of GABA to this binding site is described in the following subsection.
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What is the Barbiturate binding site?
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this is the site to which barbiturate drugs can bind (with high affinity). Clinically useful barbiturate drugs may be considered as agonists at this binding site. The effects of binding of these drugs is described in the following subsection.
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What is the Benzodiazepine binding site?
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this is the site to which benzodiazepine drugs and one or two chemically very similar drugs can bind (with high affinity). Most of the clinically useful drugs binding to this site can be considered agonists at this binding site but there is one (clinically useful) drug which is an antagonist at this binding site.
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What is the Ethanol binding site?
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this is the site to which ethanol binds to the GABAA receptor; ethanol acts as an agonist at this binding site.
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It’s important to recognize that GABA has high affinity for____ but __________?
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the GABA binding site but very low affinity for the ethanol, barbiturate and benzodiazepine binding sites.
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Thus GABA, ethanol, barbiturates and benzodiazepines _______________with each other to bind to each of the four binding sites.
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do not compete
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activation of the ethanol, benzodiazepine, or barbiturate binding sites cause essentially the same effects as GABA at the_________________________- levels
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cellular and organismal levels.
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These drugs are called Non Benzodiazepine, Non Barbiturate Hypnotics & Anxiolytics
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Buspirone & Zolpidem
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Not all drugs used to treat insomnia or anxiety are benzodiazepines or barbiturates.....What are they?
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Buspirone & Zolpidem
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What is Zolpidem?
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A Non Benzodiazepine-Barbiturate Hypnotic
Zolpidem is only used to treat insomnia. introduced in the late 1990's chemically similar to but is not actually a benzodiazepine. have high affinity for the benzodiazepine binding site of the GABAA receptor and mimics the effect of benzodiazepines. The duration of action of zolpidem is relatively short (a few hours) and zolpidem has been reported to be less likely to produce dependence or tolerance during chronic use. |
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Theoretically zolpidem could be used for other purposes for which benzodiazepines are used but…?
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there is no advantage to such use partly because of its short duration of action.
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What are muscle spasms?
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When skeletalmuscles (of limbs or trunk) contracts spontaneously and will not relax,the muscle is said to be undergoing a spasm. There are a numberof situations in which such spasms may occur including stress, physical trauma, and electrolyte imbalane.
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What type of drug and example of one drug is used for muscle spasms?
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Benzodiazepines -- not barbiturates -- are used to reduce muscle spasm.
The effects of the drug to reduce muscle spasm are within the spinal cord - enhancement of GABAergic inhibition of motor neurons innervating skeletal muscle - not at the skeletal neuromuscular junction (the synapse between motor neurons and skeletal muscle fibers) and not on the muscle fibers. - Diazepam |
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Are there other uses of benzodiazepines and barbiturates?
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Benzodiazepines have been used to "treat" ethanol or opiate drug (morphine or heroin) physical dependence and addiction.
Essentially, the benzodiazepine is used to heavily sedate the individual for 3-4 days during which there is abrupt cessation of administration of ethanol or the opiate drug. This abrupt cessation of ethanol or opiate administration normally triggers a withdrawal response which lasts several days. After the final dose of the sedation-inducing benzodiazepine, the individual will "wake up" as drug is eliminated. At this point, withdrawal process is complete but the addiction to ethanol or the opiate drug is maintained: the craving for the drug is unaltered by the sedation process and will still have to be treated. |
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What Benzodiazepines have been used to "treat" ethanol or opiate drug (morphine or heroin) physical dependence and addiction.?
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Chlordiazepoxide, Diazepam
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What is general anesthesia?
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Anesthesia literally means "lack of feeling" or "lack of sensation
In general anesthesia there is a lack of all types of sensation: vision, hearing, taste, smell, touch, pain, heat, cold, and proprioreception. In a sense, one can consider anesthesia to be "between" sleep and coma. |
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General anesthesia can be induced by?
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barbiturates, benzodiazepines and by various inhalant gases or volatile liquids.
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In this type of sedation, The individual is essentially in a form of deep sleep from which he/she can not be awoken until the drug is eliminated.
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general anesthesia
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analgesia means?
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lack of sensation of pain
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Several benzodiazepines are used as pre-anesthetic medications. What are they?
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Lorazepam, Midazolam, Diazepam
given orally or intravenously, to induce sedation and/or sleep before administration of another drug to induce and maintain general anesthesia. |
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Only one benzodiazepine is used as a general anesthetic - most often for outpatient surgery (such as removal of wisdom teeth). What is it?
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- Midazolam
- The drug is administered by intravenous injection. - One advantage of use of a benzodiazepine in an outpatient situation is that the benzodiazepine (anesthesia/sedation) effects can quickly be reversed by administration of flumazenil. |
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Only one barbiturate is used as a general anesthetic - in inpatient surgery. What is it?
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Thiopental
The drug is administered by intravenous injection. |
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Seizures are the hallmark of?
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epilepsy
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Epileptic seizures are?
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- unpredictable (in terms of their occurrence)
- not related to any obvious "abnormality" which when reversed will lead to cessation of seizure activity. - Various forms of epilepsy have been recognized based on the type of seizure and abnormal brain activity which accompanies each seizure. - It’s important to note that an epileptic individual is completely normal in terms of muscle control and brain activity in the period between seizures; seizures generally last less than 2 minutes and can be separated by less than an hour or more than a year. |
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In the case of a seizure induced by an identifiable stimulus, drug treatment is?
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- Drug treatment can not be initiated until after the first occurrence of that stimulus.
- Once the seizure-inducing stimulus is removed, further drug treatment is not required. In the case of epilepsy, prophylactic treatment is necessary after the first seizure occurs: drug treatment may be necessary for the individual’s life time in order to prevent re-occurrence of seizure activity. |
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For an epileptic, the type of drug used depends on?
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- somewhat on the type of seizures exhibited.
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What type of drug is effective in treating all types of epileptic seizure but may not be the "drug of choice" in treatment of every type of epilepsy (other drugs which do not target GABAA receptors and are not discussed in this course are also effective in many types of epilepsy.) ?
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- Benzodiazepines
- Barbiturates are effective to treat seizures but have been used less since the introduction of benzodiazepines (because of the potential for lethal overdose and for induction of hepatic enzymes and initiation of hepatic cancer). |
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What drugs are used to treat seizures/epilepsy?
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Phenobarbital, Diazepam, Clonazepam
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What is insomnia?
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Insomnia is a disorder of initiation of sleep (i.e. a delay in "falling asleep after turning out the light") and/or maintenance of sleep during the normal sleep period (i.e., awakenings during the normal sleep period).
about 30% of adults in the US complain of poor sleep or insomnia |
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Insomnia can be caused by?
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situational stress (including noise, stress, physical discomfort), by pain (arthritis, headache, angina, trauma), by drug withdrawal after chronic use (caffeine, ethanol), and by acute drug use (caffeine, amphetamine).
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Pharmacological treatment of insomnia is?
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currently mostly by use of benzodiazepines with relatively short duration of action:
the objective is to induce sleep shortly (20-30minuts) after (oral) administration of drug and to maintain sleep for 6-8hours without awakenings. It’s important to avoid use of longer acting benzodiazepines to treat insomnia because "daytime drowsiness" or "drug hangover" will be produced. |
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Which barbiturates and benzodiazepines are used as general anesthetics?
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Triazolam, Temazepam
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What is a seizure?
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A seizure or convulsion is most often considered to be an uncontrolled contraction of skeletal muscle. Limbs may become stiff as flexion and/or extension muscles contract, the trunk may become stiff as muscles in the trunk contract. Facial and neck muscles may also contact to produce stiffness of the face and neck. Limbs may alternately flex and extend and the trunk, neck and facial muscles may contract "rhythmically" so that writhing movements of the face, neck and trunk occur. Somewhat confusingly, a seizure may also be exhibited as a complete relaxation of muscles of limbs, trunk, neck and face. A seizure may also exhibit as an autonomic dysfunction or as a perception of an absent sensory stimulus such as an odor or a sound.
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A seizure may result from?
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physical trauma to the central nervous system, from electrolyte and/or acid-base upset, from a growth (abscess or tumor) in or a malformation of the central nervous system. In infants and toddlers, a seizure may result from an increase of body temperature. Seizures may also be induced by a variety of classes of drug. In these situations, once the seizure-inducing stimulus is removed, the seizure will cease and will not re-occur - although drug treatment may be important before the cause of the seizures can be removed (e.g., in the case of a tumor) or if the cause can not be removed (e.g., malformation within the brain)
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Anxiety is?
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a feeling of tension, apprehension and uneasiness related to a (real or unreal but perceived) threatening stimulus to the individual.
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Adaptive Anxiety is?
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important as a normal reaction to a real threatening stimulus: this stimulus can be physical - soldier on the battle field - or mental - an upcoming exam in a difficult course.
Adaptive Anxiety is useful to stimulate the individual to react appropriately to the anxiety-inducing stimulus - taking shelter and looking for enemy soldiers in the case of the soldier on the battle field, and looking over coursepack material and personal notes and reading relevant parts of a textbook, in the case of the student considering an upcoming exam in a course. Adaptive Anxiety thus helps the individual deal successfully with the threatening stimulus and is certainly important in terms of the "normal life" of the individual. |
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Maladaptive Anxiety occurs when?
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an individual reacts to a perceived but usually unreal threatening stimulus or a real but unthreatening stimulus in a manner that disrupts normal activities. For instance, an individual may feel apprehensive and anxious whenever he/she is in a group of unknown people: maladaptive anxiety causes the individual to "freeze up" in this situation and to not talk with the other individuals and to avoid the situation whenever it is anticipated.
Adaptive anxiety would stimulate the individual to "deal with the situation" and introduce him/herself to the other people in that situation. |
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Maladaptive anxiety includes what disorder?
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Panic Disorder, Social Phobias of various types, Post Traumatic Stress Disorder, and Generalized Anxiety Disorder.
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Benzodiazepines are used to treat all types of anxiety. What are the three types of treatment?
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Treatment can be prophylactic: the drug is taken chronically in order to prevent the feeling of anxiety emerging whenever an anxiety-inducing situation occurs.
Treatment can also be acute: the drug is taken only when the feeling of anxiety emerges in an anxiety-inducing situation or is immediately anticipated to occur. Acute treatment is possible because the drugs are absorbed rapidly from the gastrointestinal tract and rapidly enter the brain to have effect within 30 minutes. (Some forms of anxiety are also successfully treated prophylactically but not acutely with antidepressant drugs.) |
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What Benzodiazepines are used to treat anxiety?
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Diazepam, Chlordiazepoxide, Alprozalam, Lorazepam
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benzodiazepines and barbiturates can be used for the same purposes. These are?
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sedative, anxiolytic (to reduce anxiety), anti-epileptic, hypnotic (to induce and maintain sleep), and anesthesia. However, for practical reasons, the incidence of potentially lethal overdose with barbiturate drugs, the use of barbiturates is restricted.
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the benzodiazepine or barbiturate drug is administered in order to produce a therapeutic effect with relatively short latency and/or in response to an ongoing situation in which the drug would be useful. includes.....
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one might call such use "acute drug use".
These include an anxiety attack, a long lasting (greater than 5-10 minutes) seizure in an individual without a history of seizures, a muscle spasm, induction of sleep, acute treatment of ongoing and/or immediately anticipated anxiety attack, acute induction of sedation, and induction of general anesthesia. |
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benzodiazepine or barbiturate drug is administered in order a to produce a therapeutic effect in the absence of an ongoing situation in which the drug would be useful. This includes...
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one might call such use "chronic and prophylactic drug use".
These include induction of long term sedation, prevention of seizures (in epileptic individuals or individuals prone to repetitive seizures), prevention of anxiety attacks. |
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The use of each drug as its level of therapeutic effect is determined in part by?
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the pharmacokinetics (i.e. rate of absorption and elimination and administration route) of the drug, and is also dependent on the route of administration of the drug.
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Dependent on the dose, benzodiazepines and barbiturates may produce?
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sedation, sleep or anesthesia. It’s perhaps worth noting that these two classes of drug were once described as "minor tranquilizers".
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Reversal of Effect of barbiturates
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The effect of barbiturates can not be reversed by application of an antagonist drug which can bind to the barbiturate binding site (in an analogous manner to flumazenil binding the benzodiazepine binding site) of the GABAA receptor. Drugs to compete with barbiturates to bind the barbiturate binding site of the GABAA receptor and act as an antagonist at this site are unavailable!! (Clinically used barbiturates can be considered agonists at this site.)
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Tolerance of barbiturates
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With long term use, there is tolerance to barbiturate effects based on reduced sensitivity to barbiturate drugs and on more rapid elimination of the drug due to enhanced metabolism. The enhanced metabolism is due to induction of hepatic enzymes which metabolize barbiturates (and some of other drugs) by barbiturates.
Long term use is also associated with increased incidence of hepatic cancer. |
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Dependence / abuse of barbiturates
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Long term use of barbiturates is associated with physical dependence: abrupt discontinuation of the drug administration leads to signs of withdrawal. Barbiturate withdrawal is associated with anxiety, insomnia, and irritability....essentially the opposite of the (desired therapeutic) effects of the drug. Thus discontinuation of drug use (when used chronically) should be gradual not abrupt.
At low doses, these drugs cause mild excitation or arousal. This behavioral disinhibition may be interpreted as euphoria. However, the intensity of these effects is such that recreational abuse of these drugs (use "to feel good") is relatively unusual. |
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Side effects of barbiturates
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A major side effect of these drugs is a simple extension of their desired effect. For instance, a barbiturate drug’s hypnotic (sleep-inducing) effect may be longer lasting than required so that the individual feels sedated or drowsy when he/she wants and need to be fully awake and aware. This effect may occur if the dose of the drug is excessive or if a longer lasting drug is administered when a shorter lasting drug should be used. Also, a barbiturate drug may produce sedation or sleep when an anti-epileptic (not sedating, non-hypnotic) effect or an anxiolytic (anxiety reducing) effect is desired: this effect may occur if the dose of the drug is excessive.
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Overdose of barbiturates
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In overdose, barbiturates may be lethal even in the absence of other drugs (including ethanol). This effect is in part due to drug-induced, decreased sensitivity to plasma carbon dioxide concentration and the resultant decreased respiratory activity and plasma pH upset. Death results from respiratory failure perhaps accompanied by cardiac arrest
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Available Barbiturate Drugs history
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- Barbiturate drugs became available in the early 20th century.
- They have been used extensively as agents to sedate individuals and to treat insomnia, epilepsy and as general anesthetics. - the introduction of benzodiazepines which are safer drugs than barbiturates - based on relative potential for lethal overdose and for liver carcinogenesis (with chronic use) - lead to reduced use of barbiturates. - Barbiturates are still used to induce general anesthesia and to prevent seizures in some epileptic individuals. |
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Phenobarbital duration and action
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long (12-18 hour) duration of action sedative, hypnotic, anti-epileptic
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Secobarbital duration and action
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medium (6-8 hour) duration of action sedative, hypnotic
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Pentobarbital duration and action
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medium (6-8 hour) duration of action sedative, hypnotic
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Thiopental duration and action
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short (30 minutes) duration of action general anesthetic
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Tolerance of benzodiazepines
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With long term use there may be some tolerance to benzodiazepines based on reduced sensitivity to the drugs (not on more rapid elimination of the drugs).
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Dependence of benzodiazepines
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Long term use of benzodiazepines is also associated with physical dependence: abrupt discontinuation of the drug administration leads to signs of withdrawal. Withdrawal is associated with anxiety, insomnia, irritability and involuntary muscle twitches....essentially the opposite of the (desired) effects of the drug. Thus discontinuation of drug use should be gradual not abrupt.
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Abuse of benzodiazepines
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At low doses, these drugs cause mild excitation or arousal. This behavioral disinhibition may be interpreted as euphoria. However, the intensity of these effects is such that recreational abuse of these drugs (use "to feel good") is very unusual.
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Side effects of benzodiazepines
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- A major side effect of these drugs is a simple extension of their desired effect. For instance, a drug’s sleep inducing effect may be longer lasting than required so that the individual feels sedated or drowsy when he/she wants and need to be fully awake and aware. This effect may occur if the dose of the drug is excessive or if a longer lasting drug is administered when a shorter lasting drug should be used.
- a benzodiazepine drug may produce sedation or sleep when an anti-epileptic (not sedating, non-hypnotic) effect is desired or when an anxiolytic (anxiety reducing) effect is desired: these potential undesired effects may be eliminated if the dose of the drug is reduced. - Some of the drugs have also been reported to induce bizarre behaviors and hallucinations. |
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In the absence of other drugs (especially other sedatives as ethanol and barbiturates), benzodiazepine overdose is?
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not lethal.
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Available Benzodiazepine Drugs history
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Benzodiazepine drugs first became available in the 1960's.
They have been used extensively in multiple situations and have largely displaced barbiturates for each of the clinical uses for which either a barbiturate drug or a benzodiazepine drug is effective because benzodiazepines are safer (are not lethal in overdose and do not induce liver cancer. |
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Pharmacokinetic Considerations
of Barbiturates |
may be administered orally (except phenobarbital) - they are rapidly absorbed through the wall of the gastrointestinal tract - or intravenously.
Once in the plasma, the drugs (except phenobarbital) enter the brain rapidly. The rapid absorption and distribution to the brain - recall that of all the organs of the body, the brain receives the greatest proportion of blood pumped by the heart - of these drugs (except phenobarbital) permit a short latency to action and thus a variety of uses. Phenobarbital is less rapidly absorbed across the wall of the gastrointestinal tract and enters the brain from the plasma less rapidly. |
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Barbiturates are metabolized?
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In the liver. The metabolites of every barbiturate are inert and are excreted in the urine.
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Where does benzodiazepines
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metabolic pathway of each drug to its inactive, gluconuride conjugate metabolite
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What is the duration of action of Triazolam
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Short 3-8 hours
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What is the duration of action of Oxazepam
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Short 3-8 hours
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What is the duration of action of Midazolam
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Short 3-8 hours
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What is the duration of action of Alprozalam,
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Medium 10-20 hours
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What is the duration of action of Lorazepam,
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Medium 10-20 hours
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What is the duration of action of Temazepam
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Medium 10-20 hours
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What is the duration of action of Diazepam
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Long 1-3 days
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What is the duration of action of Chlordiazepoxide
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Long 1-3 days
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What is the duration of action of Clonazepam
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Extra-long: Weeks
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Benzodiazepine drugs have a common base structure
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a benzene ring ("benzo") fused to a seven-membered ring containing two nitrogen atoms (diazepine).
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Pharmacokinetic Considerations of Benzodiazepine drugs
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Benzodiazepines may be administered orally - they are rapidly absorbed through the wall of the gastrointestinal tract - or intravenously.
Once in the plasma, the drugs enter the brain rapidly. The rapid absorption and distribution (to the brain) of the drugs permit a short latency to action and thus a variety of uses.b hydroxyl-benzodiazepines. These molecules are active in the same way in which the parent (precursor) molecules are active. |
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Benzodiazepines are metabolized in?
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the liver.
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The final metabolite of every benzodiazepine is?
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molecule that is inert (a benzodiazepine gluconuride conjugate) and is excreted in the urine.
However, it’s important to realize that most benzodiazepines are first metabolized either to other benzodiazepines or an active metabolite |
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Where a benzodiazepine is metabolized to an active metabolite, what can be recognized?
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multiple Half-Lifes can be recognized.
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First, the real or chemical Half-Life of the administered molecule (benzodiazepine) can be determined from?
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- measures of plasma concentration of this drug.
- can be determined from measures of plasma concentration of each metabolite. |
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Second, the half-life of the administered molecule (benzodiazepine) can be determined from?
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a functional sense as half of the Duration of Action - a "functional half life" - of the administered drug and all of its metabolites after a dose of the administered drug.
This time period is not technically described as a Half-Life (as defined elsewhere and based on plasma concentration of the drug) but does allow functional comparison of duration of action of benzodiazepine drugs with each other. Obviously, the real Half-Life of the administered molecule and each active metabolite contributes to the functional half-life". In practical terms, it's usual to deal the Duration of Action of an administered drug rather than the "functional half life" of the drug and to somewhat ignore the roles of active metabolites of an administered drug in contributing to the drug's Duration of Action. |
