Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0021051 (immunodeficiency)
 71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Toxoplasmic encephalitis is one of the leading causes of morbidity in patients with AIDS. Lifelong treatment is needed to prevent relapses, and primary prevention is desirable in high-risk patients, but the available drugs are often poorly tolerated. Azithromycin (AZM) has been considered a drug candidate because of its efficacy in the animal model and its kinetic properties, which would allow intermittent administration. The tolerability and kinetics of AZM and its effect on the disposition of zidovudine (ZVD) were therefore evaluated in a preliminary open study in nine human immunodeficiency virus-infected patients. AZM was administered once weekly for 5 weeks 2 h before the usual morning ZVD dose. The day before and on the first and fifth AZM dosings, blood samples were drawn every 30 min during 5 h for determination of the concentrations of ZVD and its glucuronide metabolite. Blood samples were drawn for AZM measurement over 72 and 360 h on the first and fifth AZM administrations, respectively, as well as before and 3 h after dosing on the second, third, and fourth AZM dosings. After the first and fifth administrations, maximum AZM concentrations in serum were 0.6 +/- 0.1 and 0.8 +/- 0.2 microM (mean +/- standard error of the mean), respectively; times to peak concentration in serum were 3.7 +/- 0.2 and 2.9 +/- 0.4 h, respectively; areas under the plasma concentration-time curves were 9.2 +/- 1.6 and 9.3 +/- 2.0 micrograms.h/ml, respectively; and half-lives were 61.0 +/- 5.4 and 63.8 +/- 6.7 h, respectively. On days -1, 1, and 29, ZVD kinetic parameters were as follows: maximum concentrations in serum, 3.1+/- 0.6, 4.3 +/- 0.6, and 4.2 +/- 0.9 microM, respectively; times to maximum concentrations in serum, 1.1 +/- 0.4, 0.8 +/- 0.2, and 1.2 +/- 0.3 h, respectively: areas under the plasma concentration-time curves, 5.3 +/- 0.9, 5.9 +/- 0.6, and 5.7 +/- 0.8 microgram . h/ml, respectively; and half-lives, 1.3 +/- 0.08, 1.4 +/- 0.04, and 1.3 +/- 0.04 h, respectively. Except for transient mild abdominal cramps that occurred at 2 to 3 h postdose (6 of 45 exposures) and nausea (4 of 45 exposures), neither subjective nor objective side effects were observed. The kinetics of AZM were similar after the first and repeated administrations, and the disposition of ZVD was not altered by this treatment. The efficacy of AZM in preventing cerebral toxoplasmosis can therefore be safely tested in human immunodeficiency virus-infected patients concomitantly treated with zidovudine.
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PMID:Once-a-week azithromycin in AIDS patients: tolerability, kinetics, and effects on zidovudine disposition. 132 35

In June 1993, the United States Public Health Service (USPHS) made recommendations for treatment of disseminated Mycobacterium avium complex (MAC) in patients infected with the human immunodeficiency syndrome (HIV). It was suggested that every treatment regimen include either azithromycin or clarithromycin plus one or more of the following drugs: ethambutol, clofazimine, rifabutin, rifampin, ciprofloxacin, or amikacin. This study compares the effect of multiple drug therapy regimens on the survival of patients of the HIV outpatient department of the Medical Center of New Orleans, Louisiana. A retrospective chart review of 122 confirmed cases of MAC was conducted. Three treatment groups were considered: no/monotreatment (n = 40), multitreatment without clarithromycin (n = 32), and multitreatment with clarithromycin (n = 50). Azithromycin, amikacin, and rifabutin were not used in this clinic during the study period. Both multitreatment without clarithromycin (p < 0.03) and multitreatment with clarithromycin (p < 0.005) were significantly protective for survival after adjusting for CD4 cell count at time of diagnosis, nonadherence to treatment, number of concomitant opportunistic infections at diagnosis, and weight loss > 10%. Neither of the groups that received multidrug therapy were significantly less likely to have MAC-related symptoms than the no/mono group at 3 and 6 months postdiagnosis. These findings support the USPHS recommendation for multiple drug treatment either with or without clarithromycin. Prospective controlled clinical trials will clarify the optimal regimen for disseminated MAC disease.
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PMID:Comparison of multiple drug therapy regimens for HIV-related disseminated Mycobacterium avium complex disease. 774 89

Azithromycin has in vitro activity against Treponema pallidum and is effective against experimental syphilis in rabbits. We undertook an open, noncomparative pilot study of oral azithromycin (500 mg once daily for 10 days) to treat 16 patients with primary or secondary syphilis who were seronegative for human immunodeficiency virus. Cure was documented for 11 of 13 patients observed > or = 3 months; three patients were lost to follow-up. The serological response of one patient with secondary syphilis was indeterminate, and one patient with primary syphilis had either relapse or reinfection. Four patients had mild gastrointestinal side effects, and another patient had an episode of nausea and vomiting; all side effects occurred in the first 3 days and resolved spontaneously as treatment continued. Azithromycin shows promise as an alternative agent for treatment of early syphilis; controlled trials and assessment of other dosage regimens are indicated.
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PMID:Pilot study of azithromycin for treatment of primary and secondary syphilis. 781 68

Biotransformation of rifabutin, an antibiotic used for treatment of tuberculosis in patients infected with the human immunodeficiency virus (HIV), and its interactions with some macrolide and antifungal agents were studied in human intestinal and liver microsomes. Both liver and enterocyte microsomes metabolized rifabutin to 25-O-deacetylrifabutin, 27-O-demethylrifabutin, and 20-, 31-, and 32-hydroxyrifabutin. The same products (except 25-O-deacetylrifabutin) were formed by microsomes from lymphoblastoid cells that contained expressed CYP3A4. The apparent Michaelis-Menten constant (Km); approximately 10 to 12 mumol/L) and maximal velocity (Vmax; approximately 100 pmol/min/mg of protein) values for CYP-mediated metabolism were similar in liver and enterocyte microsomes. Deacetylation of rifabutin (Km approximately 16 to 20 mumol/L and Vmax approximately 50 to 100 pmol/min/mg of protein) was catalyzed by microsomal cholinesterase. Clarithromycin, ketoconazole, and fluconazole inhibited CYP-mediated metabolism of rifabutin in enterocyte microsomes equally or more potently than in liver microsomes but had no effect on cholinesterase activity. Azithromycin did not inhibit in vitro metabolism of rifabutin. This study provides evidence that CYP3A4 and cholinesterase are major enzymes that biotransform rifabutin in humans and that intestinal CYP3A4 contributes significantly to rifabutin presystemic first-pass metabolism and drug interactions with macrolide and antifungal agents.
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PMID:Metabolism of rifabutin in human enterocyte and liver microsomes: kinetic parameters, identification of enzyme systems, and drug interactions with macrolides and antifungal agents. 916 17

Two hundred and forty-six patients infected with human immunodeficiency virus (HIV) who also had disseminated Mycobacterium avium complex received either azithromycin 250 mg every day, azithromycin 600 mg every day, or clarithromycin 500 mg twice a day, each combined with ethambutol, for 24 weeks. Samples drawn from patients were cultured and clinically assessed every 3 weeks up to week 12, then monthly thereafter through week 24 of double-blind therapy and every 3 months while on open-label therapy through the conclusion of the trial. The azithromycin 250 mg arm of the study was dropped after an interim analysis showed a lower rate of clearance of bacteremia. At 24 weeks of therapy, the likelihood of patients' developing 2 consecutive negative cultures (46% vs. 56%, P=.24) or 1 negative culture (59% vs. 61%, P=.80) was similar for azithromycin 600 mg (n=68) and clarithromycin (n=57), respectively. The likelihood of relapse was 39% versus 27% (P=.21) on azithromycin compared with clarithromycin, respectively. Of the 6 patients who experienced relapse, none of those randomized to receive azithromycin developed isolates resistant to macrolides, compared with 2 of 3 patients randomized to receive clarithromycin [corrected]. Mortality was similar in patients comprising each arm of the study (69% vs. 63%; hazard, 95.1% confidence interval, 1.1 [0.7, 1.7]). Azithromycin 600 mg, when given in combination with ethambutol, is an effective agent for the treatment of disseminated M. avium disease in patients infected with HIV.
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PMID:A randomized, double-blind trial comparing azithromycin and clarithromycin in the treatment of disseminated Mycobacterium avium infection in patients with human immunodeficiency virus. 1107 59

Neisseria gonorrhoeae causes urogenital, anorectal, conjunctival, and pharyngeal infections. Urogenital tract infections are most common. Men with gonorrhea may present with penile discharge and dysuria, whereas women may present with mucopurulent discharge or pelvic pain; however, women often are asymptomatic. Neonatal infections include conjunctivitis and scalp abscesses. If left untreated, gonorrhea may cause pelvic inflammatory disease in women, or it may disseminate, causing synovial and skin manifestations. Urogenital N. gonorrhoeae infection can be diagnosed using culture or nucleic acid amplification testing. Urine nucleic acid amplification tests have a sensitivity and specificity comparable to those of cervical and urethral samples. Fluoroquinolones are no longer recommended for the treatment of gonorrhea because of antimicrobial resistance. A single intramuscular injection of ceftriaxone, 250 mg, is first-line treatment for uncomplicated urogenital, anorectal, or pharyngeal gonococcal infections. This dosage is more effective for common pharyngeal infections than the previously recommended dose of 125 mg. Ceftriaxone should routinely be accompanied by azithromycin or doxycycline to address the likelihood of coinfection with Chlamydia trachomatis. Azithromycin may be used as an alternative treatment option for patients with previous allergic reactions to penicillin, but because of the likelihood of antimicrobial resistance, its use should be limited. Gonococcal infection should prompt physicians to test for other sexually transmitted infections, including human immunodeficiency virus. Because of high reinfection rates, patients should be retested in three to six months. The U.S. Preventive Services Task Force recommends screening for gonorrhea in all sexually active women at increased risk of infection. It also recommends intensive behavioral counseling for persons with or at increased risk of contracting sexually transmitted infections. Condom use is an effective strategy to reduce the risk of infection.
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PMID:Diagnosis and management of gonococcal infections. 2315 46

Epstein-Barr virus (EBV), cytomegalovirus (CMV), and Mycoplasma pneumoniae are common pathogens of respiratory infection among children and young adults. Although single infection of 1 of these pathogens is common enough, their coinfection has been rarely reported. A 19-year-old woman presented with severe upper abdominal pain for 5 hours as well as flu-like symptoms and jaundice for 2 to 3 weeks. Initial tests found pancytopenia, abnormal liver functions, and presence of atypical lymphocytes in blood smear; the computed tomography of the abdomen revealed para-aortic lymphadenopathy, splenomegaly, and a wedge-shaped focal hypodensity lesion at the periphery of the spleen that was later diagnosed as splenic infarction. Her presentation raised suspicion of infectious mononucleosis. Nevertheless, monospot test, human immunodeficiency virus screening, and hepatitis viral serology were all negative, except that her M pneumoniae immunoglobulin M was found positive. Azithromycin was promptly given, but her fever and abdominal pain persisted. A strong suspicion of mononucleosis led to serological tests for EBV and CMV, which confirmed coinfection of EBV and CMV. By hospital day 7, her fever and abdominal pain had subsided and her liver function became normal. This case exemplifies the challenges in the diagnosis of coinfection of multiple respiratory pathogens and its associated complications. Greater awareness among clinicians would ensure an earlier and more accurate diagnosis of coinfection of EBV/CMV with other respiratory pathogen(s).
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PMID:Splenic infarction caused by a rare coinfection of Epstein-Barr virus, cytomegalovirus, and Mycoplasma pneumoniae. 2518 5