Lorazepam dependency

The benzodiazepines currently available for clinical use vary substantially in pharmacokinetics, acute euphoriant effects, and frequency of reported dependence. It is likely, therefore, than not all benzodiazepines have the same potential for abuse. Diazepam, lorazepam, and alprazolam may have greater abuse potential than chlordiazepoxide and clorazepate (Wolf et al. 1990). Similarly, oxazepam has been reported to produce low levels of abuse (Eliding 1978). Jaffe et al. (1983) found that in recently detoxified alcoholic patients, halazepam produces minimal euphoria even at a supratherapeutic dosage. The development of partial agonist and mixed agonist/antagonist compounds at the benzodiazepine receptor complex may offer an advantage over approved benzodiazepines for use in alcoholic patients. 

In contrast to chlordiazepoxide and diazepam, lorazepam and oxazepam are not metabolized into active compounds in the liver. Instead, they are excreted by the kidneys following glucuronidation. This is important because many alcohol-dependent patients have compromised liver function. Therefore, when treatment is initiated before the results of blood tests for liver function are known, as is often the case in outpatient clinics, lorazepam and oxazepam may be preferred. Patients with liver disease may still be treated with diazepam and chlordiazepoxide, but at lower doses. This can be accommodated with the loading technique, although hourly dosing with 5 mg of diazepam or 25 mg of chlordiazepoxide may be sufficient. 

Additional doses of atropine and 2-PAMC1 depending on severity. Diazepam or lorazepam to prevent seizures if >4 mg atropine given ventilatory support. 

High-potency benzodiazepines (e.g., clonazepam and lorazepam) are common alternatives to or in combination with antipsychotics for acute mania, agitation, anxiety, panic, and insomnia or in those who cannot take mood stabilizers. Lorazepam IM may be used for acute agitation. A relative contraindication for long-term benzodiazepines is a history of drug or alcohol abuse or dependency. 

Anxiety. Like psychosis, choosing a medication to treat anxiety in demented patients depends in large part on whether the anxiety is acute or longstanding. Acute severe anxiety requires rapid relief. For this, we recommend a benzodiazepine. Our first choice is lorazepam (Ativan) that is given as needed at 0.25-0.5 mg per dose. We prefer lorazepam because elderly patients tolerate it well (i.e., they metabolize it easily), and it is available in both oral and injectable forms. Oxazepam (Serax) is another benzodiazepine that older patients metabolize easily, but it is only available in oral form. When using benzodiazepines, be careful that your patients do not become overly sedated or delirious. 

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. 

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. 

American Psychiatric Association Benzodiazepine Dependence, Toxicity, and Abuse A Task Force Report of the American Psychiatric Association. Washington, DC, American Psychiatric Association, 1990 Cohn JB, Wilcox CS Low-sedation potential of buspirone compared with alprazolam and lorazepam in the treatment of anxious patients a double-blind study. J Clin Psychiatry 47 409 12, 1986 Dolovich LR, Addis A, Vaillancourt JM, et al Benzodiazepine use in pregnancy and major malformations or oral cleft meta-analysis of cohort and case-control studies. BMJ 317 839-843, 1998 Goldberg HL, Finnerty RJ The comparative efficacy of buspirone and diazepam in the treatment of anxiety. Am J Psychiatry 136 1184—1187, 1979 Kupfer DJ, Reynolds CF 111 Management of insomnia. N Engl J Med 336 341-346, 1997... 

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. 

Although b-blockers are considered the treatment of choice for akathisia, low doses of clonazepam, diazepam, or lorazepam may also reduce its severity ( 172, 389, 445, 447, 448, 449 and 450). These BZDs may be a useful alternative when a-blockers are contraindicated (e.g., in patients with asthma, insulin-dependent diabetes meilitus, cardiac conduction abnormalities) or as an adjunct when akathisia persists despite stepwise escalation of these agents ( 177). 

Most physicians felt these symptoms were a reflection of the patient s anxiety disorder and not a manifestation of dependence. Their opinions were reinforced when resumption of lorazepam therapy resulted in symptom amelioration, suggesting recontrol of the patient s anxiety disorder. Rarely were these patients considered dependent, mainly because they had not escalated lorazepam dosage, or manifested any signs or symptoms of drug-seeking behavior. They appeared to be typical medical users of prescribed medication. 

Other than slow taper, no consistently effective treatment to alleviate withdrawal symptoms has been reported. Although several compounds have been studied (e.g., b-blockers, clonidine, carbamazepine, abercamil, ondansetron), results have been contradictory ( 250). Carbamazepine, however, may be useful in seizure-prone patients (251). Valproate (VPA) has also been reported to benefit patients undergoing BZD discontinuation after long-term dependence ( 252), which may be related to VPA s potential anxiolytic properties, its ability to alleviate withdrawal phenomena, or both. The azaspirone anxiolytic buspirone has been reported ineffective in suppressing withdrawal symptoms, particularly in long-term BZD users (253, 254). Hydroxyzine has also been found beneficial in treating patients for lorazepam withdrawal (255). 

A major problem exists with dependency on the benzodiazepines highlighted by the media over the last few years. It is clear that all of the present benzodiazepines have the capability of producing a dependency state, some more than others, for example, lorazepam... 

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. 

Treatment of ethanol withdrawal is supportive and relies on benzodiazepines, taking care to use compounds such as oxazepam and lorazepam, which are not as dependent on hepatic metabolism as most other benzodiazepines. In patients in whom monitoring is not reliable and liver function is adequate, a longer-acting benzodiazepine such as chlordiazepoxide is preferred. 

Compared with focused attention, fewer studies have examined the effects of benzodiazepines on selective attention. Two studies have shown that performance on the Stroop test was impaired by lorazepam.119 131 Acute administration of triazolam and lorazepam produced dose-dependent decrements in response rate and accuracy in a simultaneous matching-to-sample task, which required subjects to determine which of two comparison visual stimuli was identical to the sample stimulus.148 161 The drug effects differed as a function of task difficulty, such that the benzodiazepine-induced impairment was reduced when discriminability of the non-matching stimulus was increased. 

High-potency benzodiazepines (alprazolam, clonazepam) generally are more effective in panic disorder than low-potency benzodiazepines (diazepam, lorazepam, etc.). Although less research has been done on the low-potency benzodiazepines, it is generally accepted that they frequently result in sedation prior to adequately relieving panic attacks. The reader is referred to the discussion of benzodiazepines in Chapter 8 for a detailed overview of mechanism of action. A critique of the issues of benzodiazepine dependence and appropriate use is given in Chapter 13-... 

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. 

The drugs in Schedule IV have a relatively low abuse potential and risk for psychological or physical dependence relative to those listed in Schedule in and include such drugs as barbital, phenobarbital, methylphe-nobarbital, chloral betaine (Beta Chlor), chloral hydrate, ethchlorvynol (Placidyl), ethinamate (Valmid), meprobamate (Equanil, Miltown), paraldehyde, methohexital, fenfluramine, diethyipropion, phentermine, chlor-diazepoxide (Librium), diazepam (Valium), oxazepam (Serax), clorazepate (Tranxene), flurazepam (Dalmane), clonazepam (Clonopin), prazepam (Verstran), lorazepam (Ativan), mebutamate, and dextropropoxyphene (Dar-von). 

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. 

Lorazepam Lorazepam is incompatible with sargramostim and aztreonam.161 Concentration and pH-dependent incompatibility of lorazepam was reported in... 

Although the shorter-acting BZs such as Xanax (alprazolam) and Halcion (triazolam) seem to be the most toxic and most prone to cause dependence, any BZ can cause these untoward effects, including the commonly used Klonopin (clonazepam) and Ativan (lorazepam). Overall, the BZs and many related medications used to treat anxiety and insomnia are potentially very brain disabling and spellbinding, and entail much graver risks than commonly recognized by health care providers and their patients. 

Akathisia has been reported in 16% of patients taking olanzapine (SEDA-21, 56). Three patients developed severe akathisia during treatment with olanzapine (20-25 mg/day) (87). In two, the akathisia resolved after withdrawal of olanzapine and in one of those olanzapine was well tolerated when reintroduced in combination with lorazepam. In the third patient, the akathisia was controlled by dosage reduction. A 33-year-old man with AIDS and a prior history of extrapyramidal symptoms with both typical antipsychotic drugs and risperidone developed dose-dependent akathisia with olanzapine 15-19 mg/day the akathisia responded to dosage reduction and beta-blockade (88). 

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