Side effects barbiturates

Barbiturates are Class II Controlled Substances and should be prescribed for no more than two weeks because of the adverse side effect. Barbiturates increase CNS depression in the elderly and should not be used for sleep. 

Side effects dependence and drug-drug interaction are the most serious side effects. Barbiturates can induce the Cyto P450 enzymes. This reduces the biood ieveis of the drugs via metaboiism. 

The glutarimide best known to the lay public, thalidomide (40), owes its reputation not to efficacy, but to the wholly unanticipated and tragic teratogenic effects elicited by this compound. It might be noted that the very efficacy and lack of the usual barbiturate side effects shown by this drug led to its prescription as a hypnotic for expectant mothers. Condensation of the phthalimide of glutamic acid (39) with ammonia at elevated... 

Convulsive disorders are still a serious therapeutic problem and new agents are being actively sought. Classical therapy was based upon the barbiturates that are no longer in favor because of their many side effects and their suicide potential. Interestingly, a seemingly minor structural variation of phenobarbital (152, shown as its sodium salt) leads to an anticonvulsant of increased potency and which has less hypnotic activity. In this case, sodium phenobarbital serves as its own base (so the yield is limited to 50%) and reacts readily with... 

Zolpidem, chemically unrelated to benzodiazepines or barbiturates, acts selectively at the y-aminobutyric acidA (GABAA)-receptor and has minimal anxiolytic and no muscle relaxant or anticonvulsant effects. It is comparable in effectiveness to benzodiazepine hypnotics, and it has little effect on sleep stages. Its duration is approximately 6 to 8 hours, and it is metabolized to inactive metabolites. Common side effects are drowsiness, amnesia, dizziness, headache, and GI complaints. Rebound effects when discontinued and tolerance with prolonged use are minimal, but theoretical concerns about abuse exist. It appears to have minimal effects on next-day psychomotor performance. The usual dose is 10 mg (5 mg in the elderly or those with liver impairment), which can be increased up to 20 mg nightly. Cases of psychotic reactions and sleep-eating have been reported. 

The side effects of barbiturates include sedation, poor physical coordination, and impaired mental performance. They also potentiate the intoxicating effects of alcohol. Barbiturates can be extremely dangerous in overdose, causing anesthesia, coma, and even death. In addition, barbiturates can cause dangerous suppression of breathing in patients with sleep apnea or other respiratory disorders. With repeated use over just a few weeks, physical dependence and tolerance to their effects can develop, leading to increasing doses to maintain the desired therapeutic effect. If a... 

Side effects of benzodiazepines include sedation, dizziness, poor coordination, and, at higher doses, amnesia. Benzodiazepines also increase the effects of alcohol therefore, alcohol use should be avoided or markedly curtailed. Benzodiazepines can also exacerbate the breathing problems of patients with sleep apnea and other respiratory disorders such as emphysema. Like the barbiturates, long-term use of benzodiazepines can lead to physical dependence, and abrupt discontinuation can produce an unpleasant, or even dangerous, withdrawal syndrome. 

Side effects of benzodiazepines include drowsiness and reduced respiratory function. In patients who are severely medically ill, especially those with lung disease, this side effect can be problematic. However, benzodiazepines are much safer in this regard than their predecessors, the barbiturates, and untreated delirium tremens, the most severe form of alcohol withdrawal, can be fatal. 

Cyclobarbitone. Use the intermediate directly above in the formula for Barbitone. This drug is less toxic than most barbiturates and side effects are seldom encountered. It is quite powerful as far as barbiturates go. Dosage is 100 to 200 mg ( /i to 3 grains), 400 mg maximum, mp 173-... 

A significant advantage of the benzodiazepines over other central nervous system depressants (e.g., the barbiturates) is that they possess a much greater separation between the dose that produces sleep and the dose that produces death. This increased margin of safety has been one of the major reasons benzodiazepines have largely replaced the barbiturates and other types of sedative-hypnotics in the treatment of anxiety and insomnia. In addition, benzodiazepine aclministration is associated with few side effects. 

Before the introduction of the benzodiazepines, a number of drugs from different chemical and pharmacological classes were used in the treatment of anxiety and insomnia. However, these drugs are more toxic and produce more serious side effects than do the benzodiazepines. Many also have signihcant abuse potential. Consequently, most of these compounds are no longer widely used. These drugs include the barbiturates (e.g., pentobarbital, amobarbital), carbamates (e.g., meprobamate), piperidinediones (e.g., glutethimide), and alcohols (e.g., ethchlorvynol). 

The first effective treatment of seizure disorders was the serendipitous finding in 1857 that potassium bromide could control seizures in some patients. Even though side effects were troublesome, the bromides were widely used for many years. Phenobarbital was introduced as a treatment for epilepsy in 1912 and was immediately shown to be markedly superior to bromides. While other barbiturates were synthesized and used, none were shown to be superior to phenobarbital, and the latter compound is still used. A chemically related... 

There appears to be little difference between benzodiazepines and kava extract in anxiolytic activity. However, kava extracts seem to have fewer side effects. Two studies with more than 3000 patients each found unwanted events in about 2% of patients during treatment with kava extract. The more frequently reported side effects were gastrointestinal complaints, allergic skin reactions, headache, and photosensitivity (Pittler and Ernst, 2000). There have been isolated reports of hepatotoxicity and acute liver failure (Escher et ah, 2001). Kava may potentiate the sedative effects of other medications including barbiturates and benzodiazepines. Kava can also cause behavioral disinhibition in a minority of individuals, including children. The most common problem, which is usually associated with persistent and excessive usage, is a scaly skin rash called kava dermopathy, which is reversible. 

Historically, alcohol has been used as an anxiety-reducing agent, both casually and in professional medical settings. In 1903, barbital was introduced as the first barbiturate to treat anxiety, and phenobarbital followed a few years later. Barbiturates have many side effects and addictive properties, and overdose can lead to coma and death. For these reasons, they are rarely used today, except to treat some forms of epilepsy. This class of drugs was eventually replaced by the benzodiazepines (see Chapter 4). 

The straightforward step used to form the ring system means that the chemistry involved in the preparation of the scores of barbiturates that have been used clinically in fact devolves on the syntheses of the various malonic esters. It should be noted that little success has been achieved in changing the side effect spectrum of these dmgs. The main differences between the various agents involve their pharmacokinetic properties these in turn are manifested as variations in bioavailablity by parenteral and oral routes as well as in time to the onset and duration of action. 

Compared to barbiturates, benzodiazepines are relatively safe medications that produce little tolerance and suppression of REM sleep, and benzodiazepine overdoses are much less common. However, benzodiazepines are not without unwanted side effects. As mentioned above, longer-acting benzodiazepines can produce residual drowsiness, grogginess, and weakness the next day (benzodiazepines are also muscle relaxants). Benzodiazepines can produce rebound insomnia, in which the person experiences significant insomnia after he or she stops taking the medication. This is particularly true with benzodiazepines that have short half-lives. To avoid this, the patient should never stop cold turkey rather, the dosage should be slowly tapered off over several days to a week. 

---