Sedatives lorazepam

A class of sedative/hypnotic type drug that exert their effects through the benzodiazepine binding site on GABAa receptors. The class consists both of molecules that contain the benzodiazepine moiety, for example diazepam, lorazepam and flunitrazepam, and the newer, non-benzodiazepine compounds such as zolpidem, zopiclone, indiplon and zaleplon. BzRAs are primarily used for the treatment of anxiety, insomnia and to elicit varying levels of sedation. The wide selection of compounds currently available affords the prescribing clinician extensive options in terms of relative efficacies and durations of action. 

However, lorazepam and oxazepam are relatively safe for older adults when given in normal dosages. Buspirone (BuSpar) also is a safe choice for older adults with anxiety because it does not cause excessive sedation, and the risk of falling is not as great. Before bus-pirone therapy is begun, benzodiazepines and sedatives and hypnotics are gradually withdrawn. Buspirone, unlike most of the benzodiazepines, must be taken regularly and is not effective on an as-needed basis. 

Other sedative-hypnotic medications, such as barbiturates, may play a useful role in severe withdrawal from this group of drugs. For example, in a case series of GBL withdrawal, use of intravenous pentobarbital in the range of 1-2 mg/kg/hour lowered the total requirement for intravenous lorazepam (Sivilotti et al. 2001). Antipsychotic medications are often used to reduce psychotic agitation. However, because antipsychotic medications lower the seizure threshold and may contribute to loss of central control of temperature leading to hyperthermia or neuroleptic malignant syndrome (NMS), they are not indicated as first-line medications for GHB withdrawal delirium (Dyer and Roth 2001 McDaniel and Miotto 2001 Sharma et al. 2001). If anti-... 

There is, however, a unique risk in the bipolar form that antidepressant treatment may trigger a switch into mania. This may occur either as the natural outcome of recovery from depression or as a pharmacological effect of the drug. Particular antidepressants (the selective serotonin reuptake inhibitors) seem less liable to induce the switch into mania than other antidepressants or electroconvulsive therapy. Treatment for mania consists initially of antipsychotic medication, for instance the widely used haloperidol, often combined with other less specific sedative medication such as the benzodiazepines (lorazepam intramuscularly or diazepam orally). The manic state will usually begin to subside within hours and this improvement develops further over the next 2 weeks. If the patient remains disturbed with manic symptoms, additional treatment with a mood stabilizer may help. 

The synthesis of these compounds will be described in Section 3.1, Opioid analgesics. Besides opioids, benzodiazepines (diazepam, lorazepam, and midazolam), which have anxiolytic, sedative, and anticonvulsant effects, that cause amnesia and muscle relaxation, are frequently used to relieve patients anxiety during anesthesia. 

Lorazepam (Ativan, Others) [C-IV] [Anxiolytic, Sedative/ Hypnotic/Benzodiazepine] Uses Anxiety preprocedure sedation control Szs Action Benzodiazepine Dose Adults. Preprocedure sedation 2.0-4.0 mg... 

The speciflc clinical use of the numerous available benzodiazepines depends on their individual pharmacokinetic and pharmacodynamic properties. Drugs with a high affinity for the GABAa receptor (alprazolam, clonazepam, lorazepam) have high anxiolytic efficacy drugs with a short duration of action (temazepam) are used as hypnotics to minimise daytime sedative effects. Diazepam has a long half-life and duration of action and may be favoured for long-term use or when there is a history of withdrawal problems oxazepam has a slow onset of action and may be less susceptible to abuse. 

Fieve RR, Platman SR, Plutchik RR The use of lithium in affective disorders, I acute endogenous depression. Am J Psychiatry 125 79-83, 1968 Fieve RR, Kumbaraci T, Dunner DL Lithium prophylaxis of depression in bipolar I, bipolar II, and unipolar patients. Am J Psychiatry 133 925-930, 1976 File SE Rapid development of tolerance to the sedative effects of lorazepam and triazolam in rats. Psychopharmacology 73 240-245, 1981... 

Benzodiazepines are highly effective anxiolytics and sedatives. They also have muscle relaxant, amnestic, and anticonvulsant properties. Benzodiazepines effectively treat both acute and chronic generalized anxiety and panic disorder. The high-potency benzodiazepines alprazolam and clonazepam have received more attention as antipanic agents, but double-blind studies also have confirmed the efficacy of diazepam and lorazepam in the treatment of panic disorder. Although only a few benzodiazepines are specifically approved by the... 

Most sedative drugs, including narcotics and alcohol, potentiate the sedative effects of benzodiazepines. In addition, medications that inhibit hepatic cytochrome P450 (CYP) 3A3/4 increase blood levels and hence side effects of clonazepam, alprazolam, midazolam, and triazolam. Lorazepam, oxazepam, and temazepam are not dependent on hepatic enzymes for metabolism. Therefore, they are not affected by hepatic disease or the inhibition of hepatic enzymes. 

In patients with acute agitation, a sedative such as lorazepam (2 mg) may be effective. 

Nevertheless, the GABAergic properties of benzodiazepines remain their most important clinical application. Over the past 30 years, the most widely used benzodiazepine drug has been diazepam (1.6). It is an anxiolytic, sedative, and muscle relaxant the anxious, depressed person becomes more outgoing and relaxed. There have been many diazepam analogs. Oxazepam (4.177) and lorazepam (4.178) have similar effects. Temazepam (4.179), flunitrazepam (4.180), and flurazepam (4.181) are useful sedative-hypnotics. Clonazepam (4.182) is a clinically useful anticonvulsant. Brotizolam (4.183), a novel benzodiazepine analog, seems to be an effective sedative-hypnotic. Midazolam (4.184) is an imidazolo-benzodiazepine that is water soluble and thus easily injectable. It is a hypnotic sedative with marked amnestic (i.e., memory loss) properties and is used in dentistry, endoscopic procedures, and induction to anesthetics in the elderly and in... 

The tranquillizers like benzodiazepines (diazepam 5-10 mg oral, or lorazepam 2 to 4 mg IM, IV are now preferred for preanaesthetic medication because they produce tranquillity, have better muscle relaxant property and smoothen induction. Other tranquillizer compounds include phenothiazines which possess sedative, antiemetic and antihistaminic properties. They can be given orally as well as parenterally. 

Diazepam, lorazepam, oxazepam, alprazolam. Details are already given in chapter Sedative and hypnotics ... 

The acute effects of a single dose of most psychotropics are terminated by redistribution. An example would be the acute sedative effects of intravenously administered lorazepam, which rapidly enters the brain from the blood. A disproportionate amount of the dose enters the CNS because of its greater vascularity in comparison with peripheral adipose tissue. Brain concentration subsequently falls as the drug redistributes out of the brain into the plasma and then into other peripheral compartments. This fall in brain concentration terminates acute psychoactive effects of a single dose of a drug such as lorazepam. 

Knowing the differential pharmacokinetics for a class of drugs allows the clinician to choose specific members to either achieve a faster onset or a delayed offset of action (13, 14, 17, 18). For example, lorazepam is rapidly absorbed from the gastrointestinal tract into the systemic circulation and from there distributed into the brain. In contrast, oxazepam, the most polar BZD, is slowly absorbed from the gastrointestinal tract. Even after oxazepam is in the systemic circulation, it slowly enters tissue compartments, including the brain, during the distribution phase. Unlike lorazepam, oxazepam is not available in either the intramuscular or intravenous formulations. Thus, lorazepam would be preferable to achieve acute control of alcohol withdrawal (e.g., delirium tremens), whereas oxazepam would better stabilize a dependency-prone patient on sedative-hypnotics, because it does not cause the euphoria seen with the more rapidly absorbed members of this class. 

Long-acting drugs such as chlordiazepoxide and diazepam and, to a lesser extent, phenobarbital are administered in progressively decreasing doses to patients during withdrawal from physiologic dependence on ethanol or other sedative-hypnotics. Parenteral lorazepam is used to suppress the symptoms of delirium tremens. 

Diazepam, lorazepam, and midazolam are used for preanesthetic medication and as adjuvants during surgical procedures performed under local anesthesia. As a result of their sedative, anxiolytic, and amnestic properties, and their ability to control acute agitation, these compounds are considered to be the drugs of choice for premedication. (The basic pharmacology of benzodiazepines is discussed in Chapter 22.) Diazepam and lorazepam are not water-soluble, and their intravenous use necessitates nonaqueous vehicles, which cause pain and local irritation. Midazolam is water-soluble and is the benzodiazepine of choice for parenteral administration. It is important that the drug becomes lipid-soluble at physiologic pH and can readily cross the blood-brain barrier to produce its central effects. 

Consistent with their depressant and sedative effects, benzodiazepines administered acutely typically decrease CFF threshold.119 120 Specifically, significant decreases have been reported for 1 mg alprazolam, 10 mg diazepam, and 15 mg quazepam 121 4 to 11 mg midazolam 122 7.5 to 50 mg oxazepam 123 1 and 2 mg lorazepam 124 and 0.5 mg triazolam and 1 mg flunitrazepam.120 As is evident, this effect on CFF threshold was observed at therapeutic doses of each drug, and when multiple doses were tested, the effect was dose-related. However, there are reports of acute, therapeutic doses of diazepam (5 mg)125 and lorazepam (1 and 2 mg)125,126 having no effect on CFF threshold. One study investigating numerous benzodiazepines120 reported next-day impairment after acute doses of triazolam (0.5 mg) and lormetazepam (1 to 2 mg). No studies were found that examined the effect of chronic benzodiazepine administration on CFF threshold. 

Frequently, a preoperative sedative is given to a patient 1 to 2 hours before the administration of general anesthesia.2,36 Sedatives are usually administered orally or by intramuscular injection, and are given while the patient is still in his or her room. This approach serves to relax the patient and reduce anxiety when arriving at the operating room. Commonly used preoperative sedatives include barbiturates (secobarbital, pentobarbital), opioids (butorphanol, meperidine), and benzodiazepines (diazepam, lorazepam) (Table 11-2). Different sedatives are selected depending on the patient, the type of general anesthesia used, and the preference of the physician. 

OFFICIAL NAMES Minor tranquilizers (sedative-hyp-notics/anxiolytics)/Benzodiazepines Alprazolam (Xanax) chlordiazepoxide (Librium, Novopoxide) clonazepam (Klonopin) clorazepate (Azene, Tranxene) diazepam (Valium) estazolam (ProSom) flunitrazepam (Rohypnol/illegal in the United States) flurazepam (Dalmane) halazepam (Paxipam) lorazepam (Ativan) midazolam (Versed) oxazepam (Serax) prazepam (Centrax) quazepam (Doral) temazepam (Restoril) triazolam (Halcion)... 

The rates of oral absorption of benzodiazepines differ depending on a number of factors, including lipophilicity. Oral absorption of triazolam is extremely rapid, and that of diazepam and the active metabolite of clorazepate is more rapid than other commonly used benzodiazepines. Clorazepate is converted to its active form, desmethyldiazepam (nordiazepam), by acid hydrolysis in the stomach. Oxazepam, lorazepam, and temazepam are absorbed from the gut at slower rates than other benzodiazepines. The bioavailability of several benzodiazepines, including chlordiazepoxide and diazepam, may be unreliable after intramuscular injection. Most of the barbiturates and other older sedative-hypnotics are absorbed rapidly into the blood following their oral administration. 

Lipid solubility plays a major role in determining the rate at which a particular sedative-hypnotic enters the central nervous system. For example, diazepam and triazolam are more lipid-soluble than chlordiazepoxide and lorazepam thus, the central nervous system actions of the former drugs are... 

Most of the sedative-hypnotics are capable of inhibiting the development and spread of epileptiform activity in the central nervous system. Some selectivity exists in that some members of the group can exert anticonvulsant effects without marked central nervous system depression (although psychomotor function may be impaired). Several benzodiazepines—including clonazepam, nitrazepam, lorazepam, and diazepam—are sufficiently selective to be clinically useful in the management of seizure states (see Chapter 24 Antiseizure Drugs). Of the barbiturates, phenobarbital and metharbital (converted to phenobarbital in the body) are effective in the treatment of generalized tonic-clonic seizures. 

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