Zolpidem (Ambien)
our most widely used hypnotic, is approved only for short-term management of insomnia. However, although approval is limited to short-term use, many patients have taken the drug long term with no apparent tolerance or increase in adverse effects. All zolp
Zaleplon (Sonata)
first representative of a new class of hypnotics, the pyrazolopyrimidines. The drug is approved only for short-term management of insomnia, but prolonged use does not appear to cause tolerance. Like zolpidem, zaleplon binds to the benzodiazepine1 receptor
Eszopiclone (Lunesta)
Like zaleplon and zolpidem, eszopiclone binds selectively with the benzodiazepine1 receptor on the GABA receptor-chloride channel complex, and thereby enhances the depressant actions of endogenous GABA.
Eszopiclone is approved for treating insomnia, with
Ramelteon
Ramelteon [Rozerem] is a relatively new hypnotic with a unique mechanism of action: activation of receptors for melatonin. The drug is approved for treating chronic insomnia characterized by difficulty with sleep onset. Long-term use is permitted. Of the
Ramelteon adverse effests
Ramelteon is very well tolerated. In clinical trials, the incidence of adverse effects was nearly identical to that of placebo. The most common side effects are somnolence (5% vs. 3% with placebo), dizziness (5% vs. 3%), and fatigue (4% vs. 2%). According
Ramelteon drug interactions and precautions
Fluvoxamine [Luvox], a strong inhibitor of CYP1A2, can increase levels of ramelteon more than 50-fold. Accordingly, the combination should be avoided. Weaker inhibitors of CYP1A2 should be used with caution. Alcohol can intensify sedation, and hence shoul
Barbiturates
These drugs cause relatively nonselective depression of CNS function and are the prototypes of the general CNS depressants. Because they depress multiple aspects of CNS function, barbiturates can be used for daytime sedation, induction of sleep, suppressi
barbiturate moa
Like benzodiazepines, barbiturates bind to the GABA receptor-chloride channel complex (see Fig. 34-1). By doing so, these drugs can (1) enhance the inhibitory actions of GABA and (2) directly mimic the actions of GABA.
Since barbiturates can directly mimi
barb cns depression
Most effects of barbiturates�both therapeutic and adverse�result from generalized depression of CNS function. With increasing dosage, responses progress from sedation to sleep to general anesthesia.
Most barbiturates can be considered nonselective CNS dep
barb cv effects
hypnotic doses, barbiturates produce modest reductions in blood pressure and heart rate. In contrast, toxic doses can cause profound hypotension and shock. How? At high doses, barbiturates depress the myocardium and vascular smooth muscle�as well as all o
barbs and hepatic drug metabolzing enzymes
Barbiturates stimulate synthesis of hepatic microsomal enzymes, the principal drugmetabolizing enzymes of the liver. As a result, barbiturates can accelerate their own metabolism and the metabolism of many other drugs.
Barbiturates stimulate drug metaboli
barb tolerance
hen barbiturates are taken regularly, tolerance develops to many�but not all�of their CNS effects. Specifically, tolerance develops to sedative and hypnotic effects and to other effects that underlie barbiturate abuse. However, even with chronic use, very
barb dependence
rolonged use of barbiturates results in physical dependence, a state in which continued use is required to avoid an abstinence syndrome. Physical dependence results from adaptive neurochemical changes that occur in response to chronic drug exposure.
Indiv
barb uses
Seizure Disorders.
Two barbiturates�phenobarbital and mephobarbital�are employed to treat seizure disorders (see Chapter 24). These drugs suppress seizures at doses that are essentially nonsedative.
Induction of Anesthesia.
Thiopental and other highly lip
barb adverse
Respiratory Depression.
Barbiturates reduce ventilation by two mechanisms: (1) depression of brainstem neurogenic respiratory drive and (2) depression of chemoreceptive mechanisms that control respiratory drive. Doses only 3 times greater than those neede
barb DIs
CNS Depressants.
Drugs with CNS-depressant properties (eg, barbiturates, benzodiazepines, alcohol, opioids, antihistamines) intensify each other's effects. If these agents are combined, fatal CNS depression can result. Accordingly, patients should be warn
barb tocicity
Acute intoxication with barbiturates is a medical emergency; left untreated, overdose can be fatal. Poisoning is often the result of attempted suicide, although it can also occur by accident (usually in children and drug abusers). Since acute toxicity fro
barb administration
Oral- Oral administration is employed for daytime sedation and to treat insomnia. Patients should be warned not to increase their dosage or discontinue treatment without consulting the prescriber. Dosages should be reduced for elderly patients. When termi