Liver functions

A Textbook of Modern Toxicology, Third Edition, edited by Ernest Hodgson ISBN 0-471-26508-X Copyright 2004 John Wiley Sons, Inc. 

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The dosage of flucytosine is 150—200 mg/kg orally in four portions every six hours. A 1% flucytosine solution has been developed for intravenous adrninistration. In some countries, a 10% ointment is also available. In patients with normal renal function, flucytosine is seldom toxic, but occasionally severe toxicity may be observed (leukopenia and thrombocytopenia). Plasma levels should be determined and the dose in patients with impaired renal function should be checked. Liver function tests (transaininases and alkaline phosphatase) should be performed regularly. In some patients with high flucytosine plasma levels, hepatic disorders have been observed (24). 

Sotalol is rapidly and almost completely (>90%) absorbed. Bioavahabhity of absorbed dmg is 89—100%. Peak plasma levels are achieved in 2—4 h. Sotalol is 50% bound to plasma proteins. Plasma half-life of the compound is about 5.2 h. No metabolites of sotalol have been identified indicating littie metabolism. The dmg is excreted mainly by the kidneys (80—90%) and about 10% is eliminated in the feces. The plasma half-life is prolonged in patients having renal failure. Kinetics of the compound are not affected by changes in liver function (1,2). Sotalol has ah the adverse effects of -adrenoceptor blockers including myocardial depression, bradycardia, transient hypotension, and proarrhythmic effects (1,2). 

Some authorities question whether dmnkeimess can result from the inhalation of ethyl alcohol vapors. Experience has demonstrated that in any event such intoxication is indeed rare (281). There is no concrete evidence that the inhalation of ethyl alcohol vapor will cause cirrhosis. Liver function is definitely impaired during alcohol intoxication (282), making the subject more susceptible to the toxic effects of chlorinated hydrocarbons. 

Xenobiotic induced disruption of female fertility follows essentially the same pattern as that of the male and can be caused by changes in pituitary-hypothalamic function, primary disruption of ovarian structure or hormone secretion, or changes in the rate of hormone deactivation. In addition, there may be changes in the synthesis of estrogen induced production of the yolk protein by the liver (vitellogenesis), which in turn can lead to failure to lay down sufficient yolk in the developing oocytes. Vitellogenesis provides a valuable biomarker for endocrine dysfunction in both sexes,but is more properly considered as part of the liver function. 

Decreased production of yolk protein resulting from inhibition of either ovarian or liver function presents the fish with a similar choice to that resulting from decreased food availability. It can produce the same number of smaller eggs, or a smaller number of eggs of normal size, but the mechanism by which that choice is made is unclear. Since the decreased nutrient content of small eggs will result in smaller larvae with a decreased survival rate, the net result in both cases may be a... 

Usual dose schedules of streptozotocin involve 500 mg/m2 i.v. during five consecutive days. The major toxicity is renal tubular damage. Treatment of metastatic insulinomas may result in the release of insulin from the tumor and subsequent hypoglycemic coma. Less severe toxicities include diarrhea, anemia, and mild alterations in glucose tolerance or liver function tests. 

Systemic treatment of 13-cis retinoic acid frequently leads to cheilitis and eye irritations (e.g., unspecific cornea inflammation). Also other symptoms such as headache, pruritus, alopecia, pains of joints and bone, and exostosis formation have been reported. Notably, an increase of very low density lipoproteins and triglycerides accompanied by a decrease of the high density lipoproteins has been reported in 10-20% of treated patients. Transiently, liver function markers can increase during oral retinoid therapy. Etretinate causes the side effects of 13-cis retinoid acid at lower doses. In addition to this, generalized edema and centrilobulary toxic liver cell necrosis have been observed. 

In liver disease, for example, the ability to metabolize or detoxify a specific type of drug may be impaired. If the average or normal dose of the drug is given, the liver may be unable to metabolize the drug at a normal rate Consequently, the drug may be excreted from the body at a much slower rate than normal. The primary health care provider may then decide to prescribe a lower dose and lengthen the time between doses because liver function is abnormal. 

More than half of the patients receiving this drug by the parenteral route experience some adverse reaction. Severe and sometimes life-threatening reactions include leukopenia (low white blood cell count), hypoglycemia (low blood sugar), thrombocytopenia (low platelet count), and hypotension (low blood pressure). Moderate or less severe reactions include changes in some laboratory tests, such as the serum creatinine and liver function tests. Other adverse reactions include anxiety, headache, hypotension, chills, nausea, and anorexia Aerosol administration may result in fatigue a metallic taste in the mouth, shortness of breath, and anorexia... 

D. that frequent liver function tests will be necessary while taking the drug... 

PYRAZINAMIDE Patients should have baseline liver functions tests to use as a comparison when monitoring liver function during pyrazinamide therapy. The nurse should monitor the patient closely for symptoms of a decline in hepatic functioning (ie, yellowing of the skin, malaise, liver tenderness, anorexia, or nausea). The primary health care provider may order periodic liver function tests. Hepatotoxicity appears to be dose related and may appear at any time during therapy. 

This drug is used cautiously in patients with peripheral vascular disease, neuropathy, chronic pancreatitis, or impaired liver function. Didanosine is a Pregnancy Category B drug and is used cautiously during pregnancy and lactation. There may be a decrease in the effectiveness of dapsone in preventing Pneumocystis carinii pneumonia when didanosine is administered with dapsone Use of didanosine with zalcitabine may cause additive neuropathy. Absorption of didanosine is decreased when it is administered with food. 

Administration may result in nausea, vomiting, headache, diarrhea, abdominal pain, and skin rash. Abnormal liver function tests may be seen and may require follow-up tests to determine if liver function has been affected. 

ITRACONAZOLE Although rare, die patient may develop hepatitis during itraconazole administration. The nurse closely monitors die patient for signs of hepatitis, including anorexia, abdominal pain, unusual tiredness, jaundice, and dark urine. The primary healtii care provider may order periodic liver function tests. 

The nurse immediately reportsany signs of acetaminophen toxicity, such as nausea, vomiting, anorexia, malaise, diaphoresis abdominal pain, confusion, liver tenderness hypotension, arrhythmias jaundice, and acute hepatic and renal failure. Early diagnoss is important because liver failure may be reversible. Toxicity is treated with gastric lavage, preferably within 4 hours of ingestion of the acetaminophen. Liver function studiesare perform ed frequently. Acetylcysteine (Mucomyst) is an antidote to acetaminophen toxicity and acts by protect-... 

MTX is potentially toxic. Therefore, the nurse observes closely for development of adverse reactions, such as thrombocytopenia (see Nursing Alert in Gold Compounds section) and leukopenia (see discussion of adverse reactions associated with hydroxychloroquine). Hematology, liver, and renal function studies are monitored every 1 to 3 months with MTX therapy. The primary care provider is notified of abnormal hematology, liver function, or kidney function finding. The nurse immediately brings all adverse reactions or suspected adverse reactions to the attention of the primary health care provider. 

A serious and potentially fatal adverse reaction to tolcapone ishepatic injury. Regular blood testing to monitor liver function is usually prescribed. The phys dan may order testing of serum transaminase levels at frequent intervals(eg, every 2 weeks for the first year and every 8 weeks thereafter). Treatment is discontinued if the ALT (SOFT) exceeds the upper normal limit or sgns or symptoms of liver failure develop. 

The MAOI antidepressant drag s are contraindicated in patients widi known hypersensitivity to die drug s, liver and kidney disease, cerebrovascular disease, hypertension, or congestive heart failure and in die elderly. These drag s are given cautiously to patients witii impaired liver function, history of seizures, parkinsonian symptoms, diabetes, or hyperthyroidism. 

In many individuals, hyperlipidemia has no symptoms and the disorder is not discovered until laboratory tests reveal elevated cholesterol and triglyceride levels, elevated LDL levels, and decreased HDL levels. Often, these drags are initially prescribed on an outpatient basis, but initial administration may occur in the hospitalized patient. Seram cholesterol levels (ie, a lipid profile) and liver functions tests are obtained before the drugs are administered. 

Periodic laboratory tests (liver function studies) and ultrasound or radiologic examinations of the gallbladder may be scheduled by the primary health care provider. 

The oral antidiabetic drugs are contraindicated in patients with known hypersensitivity to tiie drugs, DKA, severe infection, or severe endocrine disease. The first generation sulfonylureas (chlorpropamide, tolazamide, and tolbutamide) are contraindicated in patients with coronary artery disease or liver or renal dysfunction. Other sulfonylureas are used cautiously in patients with impaired liver function because liver dysfunction can prolong the drug s effect. In addition, the sulfonylureas are used cautiously in patients with renal... 

If the male or female patient is being treated for a malignancy, the nurse enters in the patient s record a general evaluation of the patient s physical and mental status. The primary health care provider may also order laboratory tests, such as serum electrolytes and liver function tests. 

FAT EMULSIONS. When a fat emulsion is administered, the nurse must monitor the patient s ability to eliminate the infused fat from the circulation. The lipidemia must clear between daily infusions. The nurse monitors for lipidemia through assessing the result of the following laboratory exams hemogram, blood coagulation, liver function tests, plasma lipid profile, and platelet count. The nurse reports an increase in any of these laboratory examinations as abnormal. 

Hepatic Effects. Normal serum liver function tests (unspecified) were observed in a 35-year-old agricultural pilot approximately 8 hours after a 45-minute dermal exposure (with presumed concurrent inhalation exposure) when his clothing became soaked in endosulfan and methomyl (Cable and Doherty 1999). 

For a variety of reasons, lipid—mainly as triacylglycerol—can accumulate in the hver (Figure 25—6). Extensive accumulation is regarded as a pathologic condition. When accumulation of lipid in the Ever becomes chronic, fibrotic changes occur in the cells that progress to cirrhosis and impaired liver function. 

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