By N. Gonzales. University of Maryland Baltimore County. 2018.
Other indications for ampicillin in- lactamase inhibitor signiﬁcantly broadens the spectrum clude serious infections like enterococcal endocarditis of antibacterial activity against -lactamase-producing and pneumonia caused by -lactamase-negative H generic danazol 50 mg fast delivery. Amoxicillin oral therapy is appropriate for in treating infections with known or suspected mixed clinically acute nonserious bacterial infections like otitis bacterial ﬂora discount danazol 100 mg mastercard, such as biliary infections 200 mg danazol, diabetic foot media and sinusitis discount 50 mg danazol free shipping. Food and Drug Administration (FDA) in pregnancy Mezlocillin, piperacillin, and ticarcillin are parenteral category B, that is, as drugs having either no fetal risk antibiotics formulated as sodium salts, so prescribers in animal studies but human trials are inadequate, or must consider the sodium content of these antibiotics animal studies show adverse fetal effects but well- when administering them to patients with congestive controlled human trials reveal no fetal damage. During their distribution phase, an- Obstetricians frequently prescribe ampicillin, penicillin tipseudomonal penicillins achieve only low concentra- G, and penicillin V because they are effective against tions in the cerebrospinal ﬂuid. Consequently, an- the infections most frequently encountered in caring for tipseudomonal penicillins are not among the drugs of pregnant women (e. In contrast, me- zlocillin has signiﬁcant hepatic metabolism and requires While being associated with a low percentage of ad- dose adjustment in patients with hepatic insufﬁciency. As ciated with penicillin use is less than 10%, including al- with the penicillins, the cephalosporin -lactam ring is lergic and other reactions. Allergic tibacterial properties of individual cephalosporins result reactions to penicillin are immediate immunoglobulin from substitution of various groups on the basic mole- (Ig) E–mediated type I immune responses. Cephalosporins also vary in acid stability and - and signs of IgE-mediated reactions may include ur- lactamase susceptibility. Late onset immune-mediated The -lactamases (penicillinases) inactivate some reactions to -lactam antibiotics may manifest as cephalosporins but are much less efﬁcient than are eosinophilia, hemolytic anemia, interstitial nephritis, or the cephalosporinases ( -lactamases speciﬁc for the serum sickness. Antibacterial Spectrum The incidence of nonallergic ampicillin eruptions is 40 to 100% in patients with concomitant Epstein-Barr The cephalosporins are classiﬁed into generations virus (mononucleosis), cytomegalovirus, acute lympho- (Table 45. The ﬁrst-generation allergic penicillin-associated rashes are characteristi- cephalosporins have in vitro antimicrobial activity cally morbilliform (symmetrical, erythematous, against streptococci, methicillin-sensitive S. The second-generation cepha- The onset of typical nonallergic eruptions is more than losporins have greater stability against -lactamase inac- 72 hours after -lactam exposure. The mechanism for tivation and possess a broader spectrum of activity to in- the nonurticarial ampicillin rash is not known and is not clude gram-positive cocci, gram-negative organisms, and related to IgE or type I hypersensitivity. Among the second-generation cephalo- tests are not useful in the evaluation of nonurticarial sporins, the cephamycins (cefoxitin [Mefoxin], cefotetan ampicillin rashes. Patients with a history of nonurticar- [Cefotan], and cefmetazole [Zefazone]) have the most ial ampicillin rashes may receive other -lactam antibi- activity against Bacteroides fragilis. The extended- otics without greater risk of subsequent serious allergic spectrum, or third-generation, cephalosporins possess a reactions. The frequency of allergic reactions to gram-negative bacteria and anaerobes while retaining another -lactam antibiotic is 5. Third-generation with a history of IgE-mediated hypersensitivity to one cephalosporins are less active against staphylococci than -lactam antibiotic plus positive results from a peni- the earlier generations. Among patients who report penicillin allergies, 80 to 90% have negative results from peni- O cillin skin tests, and 98% tolerate subsequent -lactam S antibiotic treatments. A careful history may discrimi- R C N H nate between nonallergic reactions and true penicillin allergy and permit safe -lactam therapy. N O R′ COOH -lactam ring Dihydrothiazine ring CEPHALOSPORINS 7-aminocephalosporanic acid The cephalosporins are semisynthetic antibiotics derived from products of various microorganisms, including FIGURE 45. Con- of the cephalosporins adequately treats infections comitant ingestion of food reduces the bioavailability of caused by Enterococcus faecalis, E. The cephalosporins distribute in satisfactory con- Absorption, Distribution, Metabolism, centrations to most tissues except the central nervous and Excretion system. Only cefepime, cefuroxime (Zinacef), cefo- Most parenteral cephalosporins have good bioavailabil- taxime (Claforan), ceftriaxone (Rocephin), and cef- ity after intramuscular injection, and a few members of tazidime (Fortaz) achieve therapeutic concentrations in each cephalosporin generation have good oral bioavail- cerebrospinal ﬂuid. The ester prodrugs cefuroxime ax- tibiotics of ﬁrst choice for the empirical treatment of etil (Ceftin) and cefpodoxime proxetil (Vantin) are oral brain abscess and meningitis. Drugs like ceftriaxone Among patients with morbilliform rashes (resembling that have extensive protein binding (85–95%) may dis- measles) after penicillin, the majority (95%) will toler- place bilirubin from serum albumin. Consequently, cef- ate cephalosporins without adverse effects and with no triaxone may increase the risk of kernicterus in jaun- increased risk of anaphylaxis.
Therefore proven danazol 200mg, sodium nitro- whom it is adm inistered and rarely reduces blood pres- prusside m ust be adm inistered by continuous intra- sure below the norm otensive range cheap danazol 200 mg amex. A fter the infusion is stopped quality danazol 200mg, blood In patients with coronary insufﬁciency generic 50mg danazol with mastercard, a -blocker pressure returns to predrug levels within 2 to 3 m inutes. H owever, -blockers by the kidney, toxicities due to this com pound are m ost potentiate the hypotensive effect of diazoxide, and likely in patients with im paired renal function. The dose of diazoxide should also be lowered if Pharmacological Actions the patient has recently been treated with guanethidine or another drug that depresses the action of the sym pa- In contrast to hydralazine, m inoxidil, and diazoxide, thetic nervous system. Such drugs perm it a greater hy- sodium nitroprusside relaxes venules as well as arteri- potensive effect because they reduce the increase in oles. Thus, it decreases both peripheral vascular resist- cardiac output that norm ally partially counteracts the ance and venous return to the heart. This direct action, coupled with the neuroen- sym pathetic reﬂexes, so heart rate m ay increase follow- docrine reﬂexes that are activated by a decrease in pe- ing its adm inistration even though cardiac output is not 20 Antihypertensive Drugs 231 increased. Renal blood ﬂow rem ains largely unaffected that this therapeutic approach corrects the cause of the el- by sodium nitroprusside, because the decrease in renal evated pressure. O nly in a few speciﬁc cases, such as vascular resistance is proportional to the decrease in pheochrom ocytom a, can hypertension be directly re- m ean arterial pressure. A s with all vasodilators, plasm a lated to abnorm alities in the functioning of the sym pa- renin activity increases. Clinical Uses Sodium nitroprusside is used in the m anagem ent of hy- ADRENOCEPTOR ANTAGONISTS pertensive crisis. A lthough it is effective in every form The adrenoceptor-blocking agents are described in detail of hypertension because of its relatively favorable effect in Chapter 11, although their use in the treatment of hy- on cardiac perform ance, sodium nitroprusside has spe- pertension is brieﬂy described here. Drugs of this group cial im portance in the treatm ent of severe hypertension are subdivided into -adrenoceptor antagonists ( - with acute m yocardial infarction or left ventricular fail- blockers) and -adrenoceptor antagonists ( - blockers). Because the drug reduces preload (by venodila- tion) and afterload (by arteriolar dilation), it im proves ventricular perform ance and in fact is som etim es used -Blocking Drugs in patients with refractory heart failure, even in the ab- Phenoxybenzam ine and phentolam ine have been avail- sence of hypertension. The frequency of their use for Adverse Effects the treatm ent of prim ary hypertension has greatly di- The m ost com m only encountered side effects of sodium m inished in recent years because of the developm ent of nitroprusside adm inistration are nausea, vom iting, and drugs such as prazosin that are relatively selective for headache, which quickly dissipate when the infusion is 1-receptors. Thus, the stim ulation of the heart and tends for several days, there is som e danger of toxicity renin release, actions that lim it the usefulness of classi- owing to the accum ulation of its thiocyanate m etabo- lite. Thiocyanate intoxication includes signs of delirium cal -blockers, are less with 1-selective antagonists. If nitro- U nlike the vasodilators, which have a m ore prom i- nent effect on arterial beds than on venous beds, the - prusside is adm inistered for several days, thiocyanate blockers prevent vasoconstriction in both vascular beds. Prazosin and its derivatives that are selective for 1- adrenoceptors are quite useful for the m anagem ent of prim ary hypertension. The 1-receptor–selective antag- DRUGS THAT IM PAIR SYM PATHETIC onists can be used alone in m ild hypertension. W hen hy- NERVOUS SYSTEM FUNCTIONING pertension is m oderate or severe, prazosin is generally The drugs discussed in this section reduce blood pres- adm inistered in com bination with a thiazide and a - sure by depressing the activity of the sym pathetic nerv- blocker. This is accom plished in four ways: (1) by re- considerably potentiated by coadm inistration of thi- ducing the num ber of im pulses traveling in the azides or other types of antihypertensive drugs. Since prazosin does not signiﬁcantly inﬂuence diverse and m ay best be appreciated by considering the blood uric acid or glucose levels, it can be used in hy- sym pathetic arc concerned with blood pressure regula- pertensive patients whose condition is com plicated by tion (Fig. Prazosin treatm ent is associ- W hile there m ay be som e involvem ent of the adren- ated with favorable effects on plasm a lipids. Thus, it m ay ergic nervous system in prim ary hypertension, there is be of particular im portance in m anaging patients with no clear evidence that a m alfunction of this system is hyperlipidem ia. Therefore, Further inform ation about the pharm acokinetics, even though drugs m ay depress the sym pathetic system adverse reactions, and preparations of -blockers is and thus lower blood pressure, it should not be assum ed given in Chapter 11. NTS, nucleus of the tractus solitarii; VMC, vasomotor center; ACh, acetylcholine; NE, norepinephrine;, -adrenoceptors;, - adrenoceptors; P2,P 2-purinoceptors; ATP, adenosine triphosphate.
The genetic abnormality that causes ORGANIZATIONS X-linked sideroblastic anemia was identified almost 40 AIS Support Group (AISSG) generic danazol 100 mg line. KEY TERMS Other inherited forms of sideroblastic anemia Heme—The iron-containing molecule in hemo- globin that serves as the site for oxygen binding buy 50 mg danazol amex. A rare autosomal recessive form Hemochromatosis—Accumulation of large of inherited sideroblastic anemia occurs in both males amounts of iron in the tissues of the body purchase 100mg danazol with amex. Autosomal dominant Hemoglobin—Protein-iron compound in the inheritance has also been reported buy danazol 50 mg with visa. The abnormalities blood that carries oxygen to the cells and carries that cause these anemias are not yet identified. Myelodysplasia—A bone marrow disorder that can develop into aplastic anemia requiring bone Acquired sideroblastic anemia marrow or stem cell transplantation. Acquired sideroblastic anemia often results from Nucleus—The central part of a cell that contains prolonged exposure to toxins (such as alcohol, lead, or most of its genetic material, including chromo- drugs), or nutritional imbalances (such as deficiency in somes and DNA. Other causes may Red blood cells—Hemoglobin-containing blood be inflammatory disease, cancerous conditions, or kid- cells that transport oxygen from the lungs to tis- ney, endocrine, or metabolic disorders. In the tissues, the red blood cells exchange lastic anemia sometimes surfaces in the context of a their oxygen for carbon dioxide, which is brought myelodysplastic syndrome. Removal of the toxin or treatment of the underlying disease will reverse this type of sideroblastic anemia. Acquired anemia is usually seen in patients over 65, If a mother has a female child, the child has a 50% particularly in those cases associated with myelodyspla- chance of inheriting the disease gene and being a carrier sia. On the other hand, if a mother has a male child who inherits the disease-causing gene, he will be affected and has a 100% Genetic profile chance of passing the disease gene on to his children. Hereditary sideroblastic anemia is most commonly Since the gene is defective and in the XY state there is no inherited as an X-linked recessive trait. Typical X-linked genetics Genetics of X-linked sideroblastic anemia The following concepts are important to understand- The genetic abnormality that causes X-linked sider- ing the inheritance of an X-linked disorder. All humans oblastic anemia is a mutation in the erythroid (red blood have two chromosomes that determine their gender: cell) specific form of delta-aminolevulinate synthase females have XX, males have XY. ALAS2 is the first enzyme in the heme biosyn- also called sex-linked, inheritance affects the genes thetic pathway and the mutation, when present, results in located on the X chromosome. It occurs when an unaf- the inability to transport the heme (iron) into the hemo- fected mother carries a disease-causing gene on at least globin, making it ineffective. Because females have two X The ability to test for this genetic disorder has chromosomes, they are usually unaffected carriers. X chromosome that does not have the disease-causing gene compensates for the X chromosome that does. For a Demographics woman to show symptoms of the disorder, both X chro- mosomes would need to have the disease-causing gene. That is why women are less likely to show such symp- It may be seen in maternal uncles and male cousins of toms than males. GALE ENCYCLOPEDIA OF GENETIC DISORDERS 87 Autosomal transmitted forms of the disease may cirrhosis, and heart failure from iron overload occur in both men and women. Hereditary sideroblastic anemia generally occurs X-linked sideroblastic anemia often improves with during the first three decades of life especially during pyridoxine (vitamin B6) therapy. Dosage is 50–200 mg, adolescence, but it has been diagnosed in patients over 70 however, pregnant or nursing mothers may wish to limit years old. In cases of extreme anemia, whole red blood cell Signs and symptoms transfusion may be required. Repeated whole red blood General weakness, fatigue, dizziness, and difficulty cell transfusion, however, will contribute significantly to breathing are associated with the disorder. The mucous membranes and skin of hands and arms Desferrioxamine binds excess body iron and promotes may be pale, possibly with a lemon-yellow cast. It is administered by Subcutaneous bleeding may occur, causing a brownish- intravenous infusion from a small portable pump. Side effects vary and include pain and matosis, accumulates over years in the bone marrow, swelling at injection site.
The spleen mia order danazol 200 mg online, while a reduction in the number of platelets makes the (an organ in the upper abdomen) order danazol 50mg with amex, the tonsils order danazol 50 mg visa, and the thy- person susceptible to excessive bleeding purchase danazol 50 mg without prescription. Cancerous cells mus (a small organ beneath the breastbone) are also part can also invade other organs through the circulatory system of the lymphatic system. In general, males are at a higher risk than fe- of T- and B-cell lymphomas are almost equal. Though it can GALE ENCYCLOPEDIA OF ALTERNATIVE MEDICINE 2 1283 strike people as young as 40, people between the ages of cell counts and obtain information on how well the or- 60 and 69 are at the highest risk. This information helps determine the ap- People exposed to certain pesticides and ionizing ra- propriate treatment. The doctor may also perform a bone diation have a higher-than-average chance of developing marrow biopsy. For example, an increased incidence of lym- of bone—generally from the hip—and marrow fluid are phomas has been seen in survivors of the atomic bomb removed. These samples are sent to the laboratory for ex- explosion in Hiroshima, and in people who have under- amination. In this procedure, a special shown a loose association between retroviruses, such as dye, called contrast medium, is injected into the lymphatic HTLV-I, and some rare forms of lymphoma. This dye clearly outlines the lymphatic system and relationship has not been established. Multiple x rays are then taken and The symptoms of lymphomas are often vague and any abnormality, if present, is revealed. Patients may experience loss of appetite, In rare cases a lumbar puncture (spinal tap) is per- weight loss, nausea, vomiting, abdominal discomfort, formed to see if malignant cells are in the fluid that sur- and indigestion. In this test, the physician inserts a needle of fullness, which is a result of enlarged lymph nodes in into the epidural space at the base of the spine and collects a the abdomen. Pressure or pain in the lower back is an- small amount of spinal fluid for microscopic examination. In the advanced stages, the patient may have bone pain, headaches, constant coughing, and ab- normal pressure and congestion in the face, neck, and Treatment upper chest. Only a Acupuncture, hypnotherapy, and guided imagery qualified physician can correctly diagnose if the symp- may be useful tools in treating the pain of lymphomas. Acupuncture uses a series of thin needles placed in the skin at targeted locations known as acupoints; in theory, this harmonizes the energy flow within the body, and Diagnosis may help improve immune system function. Like all cancers, lymphomas are best treated when In guided imagery, patients create pleasant and found early. However, they are often difficult to diag- soothing mental images that promote relaxation and im- nose. There are no screening tests available, and, since prove their ability to cope with discomfort and pain. An- the symptoms are nonspecific, lymphomas are rarely other guided-imagery technique involves creating a men- recognized in their early stages. Once the pain is visualized, patients by chance during a routine physical examination. When the doctor suspects lymphoma, a thorough physical examination is performed and a complete med- Herbal remedies, such as Chinese herbs and mush- ical history taken. Enlarged liver, spleen, or lymph nodes room extracts, may also lessen pain and promote relax- may suggest lymphomas. Some herbs, such as ginger, are effec- 1284 GALE ENCYCLOPEDIA OF ALTERNATIVE MEDICINE 2 tive in the treatment of nausea caused by chemotherapy, (immature cells from which all blood cells develop), that and others, such as astragalus, help build the immune normally circulate in the blood are collected, treated to system. Check with an herbal practitioner before decid- remove cancer cells, then returned to the patient in a ing on treatment. Researchers are exploring type of herb, the remedies may interfere with other pre- whether these cells can be used to restore the normal scribed medications. Naturally, any other activities that function and development of blood cells, rather than promote well-being, such as exercise, stress reduction, using a bone marrow transplant.
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