Anesthetics and Steroids

You should keep in mind that the duration of action of most of these local anesthetics can be greatly prolonged if they are taken together with the stimulant epinephrine. 

There are many types of steroid hormones in the body, such as the sex/gonadal hormones testosterone and estrogen, thyroid hormones, growth hormones, and stress hormones, which serve various normal functions. One type of steroid— corticosteroids or glucocorticoids—is secreted by the adrenal glands (located just above the kidneys). These steroids, particularly synthetic versions of them, have powerful antiinflammatory actions that help to relieve pain. They are often given as an epidural injection to relieve neck or back pain that results from a compressed or pinched nerve. They can also be injected directly into a joint to relieve pain caused by inflammation in conditions such as tendonitis (inflammation of the tendons), carpal tunnel syndrome, tennis elbow, bursitis (inflammation of sac-like cavities in tendons or muscles that allow them to slide easily over bone), or other joint pain. Professional athletes, who routinely experience one or more of these conditions, are often given local steroid injections. Frequently, the steroid is combined with a local anesthetic such as lidocaine. 

Corticosteroids usually take 3 to 7 days to start to relieve pain, and they are usually injected repeatedly to speed up the process. Prolonged used of corticosteroids to relieve pain can interfere with normal healing processes, weaken tendons, cause bone density problems, and can even damage joint 

Some common synthetic corticosteroids used to reduce inflammation (with their brand names in parentheses) are  

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Figure 1.4 Percentage of drugs that have been prescribed in the United States for 2003-2005 as a fraction of the top 200 most prescribed drugs. Note that the total of the top 200 most prescribed was 2.1 bilhon, 2.8 biUion, and 2.3 billion for 2003, 2004 and 2005, respectively. AC = Antihypertension/cardiovascular medication, SH = sedatives/antipsychotics, AI = analgesics/anti-inflammatory, AM = antimicrobial, GI = gastrointestinal, AD = antidiabetic, DE = diuretics/electrol3ftes, TH = thyroid drugs. Re = respiratory, CR = contraceptives/ reproductive therapy, BP = biophosphonates and other anti-bone loss, St = steroids. He = hematology, Nu = nutritional, Tr = triptan, AP = antineoplast, AN = anesthetic, and DI = dopaminergics and immunomodulators.

Abscesses, exudates, body glands, and tumors hinder the distribution of drugs in the body. In addition, antibodies do not distribute well at abscess and exudates sites. The placenta metabolizes some drugs making then inactive and thereby protecting the fetus from drugs given to the mother. However, steroids, narcotics, anesthetics, and some antibiotics can penetrate the placental barrier and cause adverse effects to the fetus. 

Fales and Pisano (1964) have discussed the gas chromatography of amines, alkaloids, and amino acids. Pollock and Kawauchi (1968) have resolved derivatives of serine, hydroxyproline, tyrosine, and cysteine, as well as racemic aspartic acid and tryptophan. VandenHeuvel and Horning (1964) have listed derivatives of steroids that can be separated. VandenHeuvel et al. (1960) first described the separation of bile acid methyl esters and Sjovall (1964) has extended the methods to bile acids. Gas liquid chromatography (GLC) is useful in the analysis of pesticides, herbicides, and pharmaceuticals (Burchfield and Storrs, 1962). Analysis of alkaloids, steroids, and mixtures of anesthetics and expired air are other examples of the application of this very useful technique. Beroza (1970) has discussed the use of gas chromatography for the determination of the chemical structure of organic compounds at the microgram level. 

The anesthetic and anxiolytic effects of androgens, mainly T and 5a-androstane-3a,17(S-diol (3a,5a-Adiol), is another hot topic these steroids are classified now as, not only androgens, but also neuroactive steroids. The determination of the brain and circulating levels of these steroids in animal models is useful for the elucidation of their physiological roles and pharmacological effects. Based on this information, papers that deal with the determination of these steroids in the rat brain and serum/plasma are recently increasing. 

AHopregnanolone and similar A-ring-reduced pregnanes potentiate GABA effects at these receptors. These steroids mimic the effects of the benzodiazepines, changing chloride ion conductance and producing sedative and hypnotic behavioral effects (276,277). Neuroactive steroids can be therapeutically useful as anticonvulsants, anxiolytics, or anesthetics (qv) (see also Hypnotics, sedatives, anticonvulsants, and anxiolytics). 

Glycine receptor function is modulated by alcohols and anesthetics [4]. Amino acid residue al(S267) is critical for alcohol potentiation, as mutation to small residues (Gly, Ala) enhance, and mutation to large residues (His, Cys, Tyr) diminish the ethanol effect. Glycine recqrtor modulation by Zn2+ involves structural determinants located within the large N-terminal domain. Additional glycinergic modulators include neuroactive steroids and the anthelmintic, ivermectin, which activates glycine receptors by a novel, strychnine-insensitive mechanism. 

Classical or conventional pharmaceutical agents in combination with lactide/glycolide polymers have been widely studied since about 1973. In general, these compounds are bioactive agents usually produced by synthetic chemistry, with molecular weights of less than a few hundred and relatively stable structures. Examples include steroid hormones, antibiotics, narcotic antagonists, anticancer agents, and anesthetics. 

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