Nonbenzodiazepine sedative-hypnotics

Zaleplon (Sonata) [C IV] [Sedotive/Hypnotic] Uses Insomnia Action A nonbenzodiazepine sedative/hypnotic, a pyrazolopyrimidine Dose 5-20 mg hs PRN -1- w/ renal/hepatic insuff, elderly Caution [C, /-] w/ mental/ psychological conditions Contra Component allergy Disp Caps SE HA, edema, amnesia, somnolence, photosens Interactions t CNS depression W/ CNS d es-sants, imipramine, thioridazine, EtOH X effects W/ carbamazepine, phenobarbital, phenytoin, rifampin EMS Concurrent EtOH can t adverse CNS effects OD May cause profound CNS depression symptomatic and supportive Zanamivir (Relenza) [Antiviral/Neuramidase Inhibitor] Uses Influenza A (including HlNl swine flu) B Action X Viral neuraminidase Dose Adults Feds > 7 y.2 inhal (10 mg) bid for 5 d initiate w/in 48 h of Sxs Caution [C, M] Contra Pulm Dz Disp Powder for inhal SE Bron-chospasm, HA, GI upset EMS Does not reduce risk of transmitting virus monitor for bronchospasm or other severe resp events OD May cause resp problems s5rmptomatic and supportive... 

Zolpidem is an imidazopyridine, with a chemical structure of N,N,6-trimethyl-2-(4-methylphenyl)-imidazo [ 1,2-alpha] -pyridine-3-acetamine hemitartrate (Salva and Costa, 1995). This nonbenzodiazepine sedative hypnotic was first released in Europe, and then introduced in the United States in 1993 (Hobbs et ah, 1996). Zolpidem has a strong sedative effect that seems to preclude its use as an anxiolytic. It has only weak anticonvulsant effects (Salva and Costa, 1995 Hobbs et ah, 1996). 

Noguchi, H., Kitazumi, K., Mori, M., and Shiba, T. (2002) Binding and neuropharmacological profile of zaleplon, a novel nonbenzodiazepine sedative/hypnotic. Eur ] Pharmacol 434 21—8. 

The fundamental neurobiological importance of the GABA A receptor is underscored by observations that even more receptor sites exist at or near this complex (Fig. 8—20). This includes receptor sites for nonbenzodiazepine sedative-hypnotics such as zolpidem and zaleplon, for the convulsant drug picrotoxin, for the anticonvulsant barbiturates, and perhaps even for alcohol. This receptor complex is hypothetically responsible in part for mediating such wide-ranging CNS activities as seizures, anticonvulsant drug effects, and the behavioral effects of alcohol, as well as the known anxiolytic, sedative-hypnotic, and muscle relaxant effects of the benzodiazepines. 

The newer sedative-hypnotics that are not benzodiazepines are rapidly becoming the first-line treatment for insomnia. These agents not only have pharmacodynamic advantages over benzodiazepines in terms of their mechanism of action, but perhaps more importantly, pharmacokinetic advantages as well. Three nonbenzodiazepine sedative-hypnotic agents that are now available are zaleplon (a pyrazolopyrimidine), zopiclone (a cyclopyrrolone not available in the United States), and zolpidem (an imidazopyridine) (Figs. 8—28-8—30 Table 8—4). 

Zolpidem (Fig. 8—29). This was the first omega 1 selective nonbenzodiazepine sedative-hypnotic and rapidly replaced benzodiazepines as the preferred agent for many patients and prescribers. It has a somewhat later peak drug concentration (2 to 3 hours) and longer half-life (1.5 to 3 hours) than zaleplon. 

The nonbenzodiazepine sedative-hypnotics zaleplon, zolpidem, and zopiclone are replacing benzodiazepine sedative-hypnotics as first-line treatments for insomnia. Some antidepressants, such as sedating tricyclic antidepressants and trazodone, are also used as sedative-hypnotic agents for the treatment of insomnia. 

Nonbenzodiazepine sedative-hypnotics. The non-BZD hypnotic zolpidem (Ambien) is a newer sleeping agent that is thought to work on more specific subdivisions of the GABA receptor complex than, for example, some of the older benzodiazepine agents. It is indicated for short-term insomnia and is generally limited to seven to 10 days of use. 

Alcohol is a central nervous system depressant that shares many pharmacologic properties with the nonbenzodiazepine sedative hypnotics. 

Compound 24 is a gamma-aminobutyric acid (GABA) receptor modulator that interacts with the GABA-A sub-type which is, in turn, the same locale where the classical benzodiazepine anxiolytics are also thought to interact (diazepam or Valium being a common benzodiazepine structure shown above as 57). Although 24 is classed as a nonbenzodiazepine sedative-hypnotic because it has... 

Does flumazenil reverse the CNS effects of nonbenzodiazepine sedative hypnotics ... 

Alcohol, barbiturates, and sedative-hypnotics (nonbenzodiazepines) Support vital functions None B3... 

Insomnia is a common comorbid condition with depression, and frequently is made worse by antidepressants, particularly the SSRIs. When insomnia persists despite adequate evaluation and attempts to reduce it by other approaches, it is often necessary to use a concomitant sedative-hypnotic, especially a short-acting nonbenzodiazepine with rapid onset such as zaleplon or zolpidem. At times a benzodiazepine sedative hypnotic such as triazolam or temazepam may be necessary. If anxiety persists during the day and cannot be otherwise managed, it may be necessary to add an anxiolytic benzodiazepine such as alprazolam or clonazepam. Use of sedative-hypnotics and anxiolytics should be short-term whenever possible. 

Nonbenzodiazepine ligands at benzodiazepine sites This is a variation on the theme of partial benzodiazepine agonists, as these agents act at the same or similar site as benzodiazepines but are not structurally related to them. Thus, the pharmacology of nonbenzodiazepines is that of a partial agonist, but their chemistry is different from that of a benzodiazepine. This is similar to the approach that novel sedative-hypnotics such as zaleplon and zolpidem have taken, and perhaps a less sedating nonbenzodiazepine partial agonist could hold promise for the treatment of panic disorder. 

Sedative-hypnotics fall into two general categories benzodiazepines and nonbenzodiazepines (Table 6-1). At present, benzodiazepines are typically used to promote normal sedation and sleep, especially in relatively acute or short-term situations. These agents will be addressed first, followed by a description of the nonbenzodiazepine hypnotics. 

Several other nonbenzodiazepine compounds can be prescribed for their sedative-hypnotic properties (see Table 6-1). These compounds are chemically dissimilar from one another, but share the ability to promote relaxation and sleep via depressing the CNS. Cyclic ethers and alcohols (including ethanol) can be included in this category, but their use specifically as sedative-hypnotics is fairly limited at present. The recreational use of ethanol in alcoholic beverages is an important topic in terms of abuse and long-term effects. However, since this area is much too extensive to be addressed here, only their effects as sedative-hypnotics is considered. 

Using molecular biological techniques, point mutations of the a subunits have revealed that the sedative effects of the benzodiazepines likely result from an Interaction with the ai subunit, whereas the anxiolytic effects result from an interaction at the 02 subunit (27,28), as shown in Figure 15.10 and Table 15.3. Nonbenzodiazepine receptor agonists, such as the sedative-hypnotics indiplon, zaleplon, zolpicone, and zolpidem (see Chapter 19), are ai subunit-preferring ligands, as shown in Table 15.3 (29). 

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