Shiraz Emedical Journal
Volume:2 Issue: 2, Apr 2001

Pathogenesis of nephrolithiasis is based on metabolic and environmental/nutritional factors. Metabolic factors involved in stone formation include hypercalciuria (found in 50% of patients and its most common cause is increased intestinal calcium absorption), hypocitraturia (for example due to distal RTA or UTI), hyperuricosuria, hyperoxalaturia, cystinuria and infections. Environmental / nutritional factors include dehydration (e.g., exercise in hot climates), high salt intake, a diet rich in animal proteins and calcium rich diet when oxalate intake is restricted. Evaluation of urinary stone begins with stone analysis. Review of patient’s history regarding predisposing factors is essential. Pharmacological and nonpharmacological therapies should bee targeted to the underlying cause, additionally; high fluid intake plays an essential role in the treatment.

The clinical spectrum of HIV infection includes primary infection, asymptomatic infection, early symptomatic infection, and advanced immunodeficiency with opportunistic complications. A careful history is needed in HIV-infected patients for the first time, focusing specifically on common HIV related symptoms. A complete physical examination should be performed on all patients at the time of the initial encounter. Laboratory studies that should be obtained on new patients should include CBC with differential, chemistry panel, CD4+ cell count, quantitative HIV RNA or bDNA assay, VDRL or RPR, anti-toxoplasma IgG, anti-CMV, PPD skin test, and a pap smear in women. HIV serology - HBs Ag, anti-HAV IgG, HBsAb or anti HBc Ab, anti HCV Ab, G6PD level, chest radiography and anti varicella IgG should be ordered in selected patients. Prophylaxis against PCP, toxoplasosis, TB, MAC and CMV should be considered in selected patients. CD4+ cell counts and viral load measurement every 3-6 months is the main follow up program in asymptomatic cases (in addition to above lab tests). CD4+ cell counts and viral load measurement is also used for anti-viral therapy response monitoring and for necessity of opportunistic infection prophylaxis or treatment. There are now 15 available agents that suppress HIV viral replication, representing three distinct classes. An initial regimen of three antiretroviral medications that includes a protease inhibitor or nonnucleoside reverse transcriptase inhibitor which is considered the standard of care to maximally suppress viral replication. Live virus or live bacterial vaccines (including BCG, OPV, oral typhoid vaccine (type 21) VZV vaccine, and yellow fever vaccine) should not be given to HIV-infected individuals. Pneumococcal vaccine, influenza vaccine, hepatitis vaccine (both HBV and HAV), hemophilus influenza type -B vaccine and tetanus-diphtheria vaccine (Td) is recommended for HIV-infected individuals. Response to vaccination is greater with higher CD4+ cell counts.

Halothane, first synthesized in 1951, may cause fatal and nonfatal hepatitis in one of 9000 recipients and fatal hepatitis in 1 of 40000 recipients. Female sex, age, intrahepatic hypoxia, repeated halothane exposure, obesity, alcohol, genetic predisposition and enzyme induction have been considered to be risk factors. The more common mild form may result from reductive biotransformation of halothane, possibly influenced by genetic factors or reduced liver oxygenation, whereas the rare fulminant form is most likely to be immune mediated. Halothane hepatotoxicity is idiosyncratic. Clinical Manifestations include fever, malaise, anorexia, nausea, vomiting, jaundice, skin rash, liver tenderness. Fulminant hepatitis is rarely seen. Eleveated serum transaminases, alkaline phosphatase and bilirubin and eosinophillia are also seen. Manifestations usually begin 4 days after exposure. Treatment includes supportive care. Liver transplantation may be needed in severe fulminant cases. Prognosis of those who develop jaundice is grave (with 14 –70% mortality). Other cases have much better prognosis. In order to prevent hepatotoxity, halothane exposures should be at least 6 months apart.

Chloramphenicol, Cotrimoxazole, Quinolones, Third generation cephalosporins, in addition to steroids are studied here. Chloramphenicol is the gold standard antibiotic, which clears blood from S typhi in a few hours and stool in a few days. Oral administration is preferred. However, resistance, relapse, bone marrow suppression and etc. are major disadvantages. Resistance against cotrimaxazole is high. Quinolones (e.g., ciprofloxacin which is the drug of choice in multidrug resistance) and third generation cephalosporins (e.g., ceftriaxone which is the best choice in children) are used in areas with a high prevalence rate of multidrug-resistant salmonella infection. Glucocorticoid administration is controversial, although it reduces the mortality in severe cases if used for 48 hours, steroid treatment over 48 hours may increase relapse rate. Surgical therapy is usually needed for complications (e.g., bowel perforation). Relapse of typhoid fever should be treated the same as patients with the first attack. Chronic fecal carriers (asymptomatic excretion for a year or more) should receive high doses of Ampicillin or Amoxicillin (100mg/kg/d) plus probenecid (30mg/kg/d) or Co-trimoxazole(160/800 mg twice daily) for at least 6 weeks. Those who have gallstone need cholecystectomy. Iranian studies show that cefixime is effective on all strains. Typhoid fever is a severe systemic infectious disease. Treatment with appropriate antibiotics is essential for recovery. In this article we review some current antibiotics used for the treatment of typhoid fever.