Chemistry

The field of laboratory medicine continues to expand rapidly, and with it the specialty of clinical chemistry. Perhaps chemistry is one area in which changes are occurring most rapidly, because of the variety of automated instrumentation available.

The clinical chemistry laboratory is based on quantitative analytic procedures or analytic chemistry. Physicians depend on the clinical chemistry department for delivery of test results such as glucose (blood sugar), electrolytes, and renal function tests, so that he may properly diagnosis and manage various diseases.

Crestwood Medical Center is proud to offer to the online community a database of some of the tests performed by the clinical chemistry laboratory. In order to access this information simply page down. Please bookmark our page for easier access.

Sodium

An important blood component, sodium plays a role in maintaining blood pressure, nerve condition, and acid-base balance. Decreased serum sodium or hyponatremia may be found in the following conditions: diuretic therapies , ketonuria, adrenal insufficiency, diarrhea, vomiting, "third-space" loss, burns, and salt wasting nephropathies, hypothyroidism, chronic disease, and inappropriate secretion of vasopressin. Increased serum sodium or hypernatremia may be encountered in the following conditions: profuse sweating, diabetes insipidus, Cushing's Syndrome, hyperaldosteronism, diarrhea in children without adequate fluid replacement.

Potassium

In combination with chloride and sodium, potassium plays a role in maintaining acid-base balance and water balance in the body. All body cells, especially muscle tissue, require a high concentration of potassium. Hypokalemia or decreased serum potassium can be caused by gastrointestinal fluid loss, renal losses (Diuretics), metabolic alkalosis, renal tubular acidosis, and mineralocorticord excess. hyperkalemia or increased serum potassium can be caused by cellular damage (hemolysis), fever, acute and chronic renal failure, and Addison's disease. Both increased and decreased potassium levels may have profound effects on the neuromuscular system (apathy, weakness, and paralysis). Serious cardiac arrhythmia's may result in death if not treated properly.

Chloride

A long with sodium, CO2, and potassium, chloride plays a role in maintaining acid-base balance in your body. Most ingested chloride is absorbed and the excess is secreted in the urine. Decreased serum chloride or hypochloremia is seen when there is excessive loss of chloride from the body. Decreased chloride levels can be caused by the following: gastrointestinal (HCL) losses, diabetic ketoacidosis, salt losing renal diseases, metabolic alkalosis, and compensated respiratory acidosis. Increased serum chloride or hyperchloremia may be caused by the following: metabolic acidosis, hyperparathyroidism, hyperalimentaion, renal tubular acidosis. Measurement of chloride in sweat is a diagnostic tool for the evaluation of cystic fibrosis. Elevated sweat chloride levels will usually be observed in these individuals.

Blood Urea Nitrogen

Blood Urea Nitrogen or BUN is the concentration of nitrogen in the serum in the form of urea. The BUN level can indicate how the kidney's are functioning. Increased BUN levels can be seen in uremia, increased protein catabolism (fever, stress, burns), acute or chronic renal disease, dehydration, edema, and urinary tract obstruction where urea is reabsorbed into the circulation. Decreased BUN levels only occurs in a few instances: poor nutrition, excessive IV fluids, and severe liver disease. The BUN level can be considered a rough guide to renal function.

Creatinine

Creatinine is a compound present in the urine, muscle, and blood that indicate how the kidneys are functioning.

CO2

Total CO2 measurements are used together with other clinical laboratory test for the evaluation of acid-base balance in your body. Acid-base status is a measure of how well your kidneys and/or lungs are functioning. Increased CO2 levels are observed in chronic obstructive pulmonary diseases (COPD), and hypoventalation. Decreased levels are commonly seen in Diabetic Ketoacidosis and hyperventilation.

Glucose

Glucose is the most important sugar in the blood. Hyperglycemia or increased serum glucose can be seen in the following disease states: diabetes mellitus, chronic pancreatitis, pancreatectomy, acromegaly, Cushing's syndrome, thyrotoxicosis, steroid use, oral contraceptives, chronic renal failure, chronic liver disease, infection, pregnancy, and insulin receptor antibodies. Hypoglycemia or decreased serum glucose can be caused by the following: alcohol, insulin, salicylates, insulinoma, hypopituitarism, functional hypoglycemia, and alimentary hypoglycemia.

Total Protein

Total protein is the measurement of several different types of proteins in the body: Pre-albumin, Albumin, Alpha-1- antitrypsin, Alph-2- macroglobulin, Haptoglobin, Beta-lipoprotein, transferrin, C3 (Complement), Fibrinogen, Immunoglobulins A,D,E,G, and M.

• Decreased Pre-albumin levels maybe a marker for poor nutritional status.
• Albumin is the single most abundant protein in the plasma. The normal range of albumin is 3.2 - 4.5 g/dl. Decreased levels of albumin may be caused by ascites, protein losing nephrophathy, and the condition analbuminenia. Elevated levels of albumin may occur in dehydration and by prolonged application of a tourniquet for venipuncture.
• Alpha-1-Antitrypsin may be decreased in pulmonary emphysema.
• Alpha-2-Macroglobulin is greatly increased in individuals with nephrotic syndrome.
• Haptoglobin levels can be increased in individuals with stress, infection, acute inflammation, and tissue necrosis. Decreased Haptoglobin levels are caused by hemolysis (transfusion reaction), thermal burns, and autoimmune hemolytic anemia.
• Increased Transferrin levels are caused by short term Iron deficiency and pregnancy. Decreased levels may be seen in protein losing nephropathy.
• Fibrinogen is the most abundant of the plasma coagulation factors. Increased levels of fibrinogen can be seen in pregnancy, acute phase reactants, and in the use of birth control pills. Decreased levels may be seen in any condition with extensive activation of coagulation with the formation of fibrinogen.

Calcium

Calcium is the most abundant mineral element in the human body. Approximately 98% of total calcium in the human is present in the skeletal system. Decreased calcium levels in the body can be caused by renal osteodystrophy, osteomalacia, hypoparathyroidism, and Fanconi's syndrome. Increased calcium levels can be caused by primary hyperparathyroidism, Paget's disease, vitamin D intoxication, and hypophosphatasia.

Phosphorus

Phosphorus is found in the plasma as Inorganic phosphorus rather than elemental phosphorus. Measurements of inorganic phosphorous are used primarily in the diagnosis and treatment of parathyroid gland and kidney diseases. Decreased levels of phosphorus can occur in the following conditions: primary hyperparathyroidism, osteomalacia, Fanconi's syndrome, renal tubular acidosis, and vitamin D resistant rickets. Increased levels of phosphorus can occur in the following conditions: hypoparathyroidism, renal osteodysthrophy, and pseudohypoparathyroidism.

Magnesium

Magnesium is one of the most abundant elements in the body and is essential to many physiochemical processes. Manifestations of magnesium depletion include weakness, tetany, convulsions, and cardiac arrhythmia. Causes for hypomagnesemia include malabsorbtion, severe diarrhea, alcoholism, acute pancreatitis, malnutrition, and diabetes. Hypermagnesemia can be caused by advanced renal failure, acute diabetic acidosis, Addison's disease , and ingestion of excessive amounts of magnesium containing antacids.

Gamma GT

Gamma-Gutamyl Transferase is an enzyme found abundantly in the kidneys, liver, and pancreas. Since GGT is a microsomal enzyme, tissue levels increase in response to microsomal enzyme induction. This may explain increased serum levels in chronic alcoholics and patients taking Dilantin. Serum GGT has been useful in the evaluation of chronic alcoholism, the alcoholic who has been abstinent should show a reduction of previously elevated serum GGT levels.

Amylase

Amylase is a digestive enzyme that helps your body process starches. The normal range varies greatly depending on test methodology. Serum amylase can be increased in the following conditions: pancreatitis, pancreatic carcinoma, diabetic ketoacidosis, cholecystitis, viral hepatitis, lung cancer, and ruptured ectopic pregnancy. Decreased amylase activity may be found in congestive heart failure, pregnancy (second or third trimester), and bone fractures.

Lipase

Lipase is a digestive enzyme that accelerates the breakdown of fats. Increased serum Lipase can occur in acute pancreatitis, mumps, and salivary gland disease. When used with serum amylase levels, both lipase and amylase are elevated in 90 - 97% of acute pancreatitis cases.

Creatine Phosphokinase

Creatine Phosphokinase is an enzyme that is found in high concentrations in the skeletal muscle, brain tissue and in the heart. Therefore it is a front line test for acute myocardial infarctions (MI or "heart attack"). The CK is composed of three fractions CK-BB (from the brain), CK-MB (from the heart), and CK-MM (from the muscle). CK-MB is used most often as an indicator of myocardial infarction or heart attack. Increased levels of total CK also can occur in muscular dystrophy, delirium tremens, trauma, and hypothyroidism.

Iron

Iron is essential to most living organisms and participates in a variety of processes varying from cellular oxidation to the transport of oxygen to the tissues. Increased levels occur in iron poisoning, hemolytic anemia, hemochromatosis, oral contraceptives, thalassemia, and viral hepatitis. Decreased levels occur in chronic infections, blood loss, menstruation, late pregnancy, and inadequate iron intake.

Aspartate Amino Transferase (AST, SGOT)

AST is distributed in all body tissues, but highest activities are in the liver, heart, and skeletal muscle. High activity also exists in erythrocytes. Increased serum AST levels can occur in viral hepatitis, liver cell necrosis, liver damage of any form, hepatic metastases, infectious mononucleosis, and acute MI.

Ammonia (NH3)

Ammonia is generated in the gastrointestinal (GI) tract, then absorbed through the portal vein, and removed by the liver. The relationship between elevated ammonia levels and liver disease has been recognized for many years. Increased ammonia levels are associated with fulminant hepatic failure, Reye's syndrome, cirrhosis, GI bleeding, and portal-systemic shunting of blood.

Alkaline Phosphatase (ALP)

ALP is an enzyme that originates in the liver, bone, intestine, endometrium, and lung. ALP activity usually increases in children during periods of rapid growth. Increased ALP levels can be associated with the following: healing of fractures, juvenile rickets, metastatic carcinoma of the bone, myeloma, Paget's disease, infectious mononucleosis, CMV infections in infants, cholangitis, cirrhosis, liver abscess, extrahepatic biliary obstruction, regional enteritis, and intra abdominal infections. Decreased ALP levels may occur in hypothyroidism, scury, anemia, hypophosphatasemia, and cretinism.

Alanine Aminotransferase (ALT, SGPT)

ALT is an enzyme that is present in very high amounts in the liver and kidney, with smaller amounts in the skeletal muscle and heart. Increased levels of ALT can occur in the following: liver cell necrosis, right heart failure, acute anoxia, cirrhosis, obstructive jaundice, liver tumors, myositis, and chronic alcohol abuse. It is believed by some that if the ALT levels remains high after an attack of acute hepatitis, this suggest non resolution of the disease and high risk for the development of chronic hepatitis.

Lactate Dehydrogenase (LDH)

LDH is an enzyme that is widely distributed in mammalian tissues, being rich in myocardium, liver, kidneys, and skeletal muscle. Increased LDH levels can be associated with the following: megaloblastic anemia, extensive carcinoma, viral hepatitis, cirrhosis, obstructive jaundice, hemolytic anemia, lymphoma, MI (heart attack), and congestive heart failure.

Total Cholesterol

Cholesterol in humans is a key intermediate in the biosynthesis of related sterols such as bile acids, adrenocortical hormones, androgens, and estrogens. Sixty-five to seventy-five per cent of the plasma cholesterol is transported by low density lipoprotein (LDL) and fifteen to twenty per cent is transported by high density lipids (HDL). Increased plasma cholesterol can occur in the following: familial hyperlipoproteinemia type IIA, IIB, I, IV, III, V, Werners disease, anorexia nervosa, diet high in cholesterol/saturated fats, and many other disease states. Decreased cholesterol levels occur in the following: Tangier disease, hypolipoproteinemias, hepatocellular necrosis, thalassemia, sideroblastic anemia, neoplasm of the liver, COPD, and extensive burns. Refer, also, to lipid profiles.

Triglycerides

Triglycerides are one of many forms that fat takes on while traveling in your blood. They are the main storage lipids in the body and constitute about 95% of adipose tissue lipids. Increased levels of Triglycerides may occur in hyperlipoproteinemia type I, IIb, III, IV, V, viral hepatitis, excess caloric intake, cirrhosis, alcoholism, and stress. Decreased levels can be seen in hypolipoproteinemias, COPD, brain infarction, hyperthyroidism, and malnutrition.

Bilirubin

Bilirubin, a pigment that is present in bile, is what makes a person with jaundice look yellow. Elevated bilirubin levels may indicate concerns with the liver.

Lipid Profiles

A lipid profile is a battery of tests useful to the physician in diagnosing, treating, and predicting atherosclerosis. Atherosclerosis results from the thickening of the inner layer of arterial walls. This thickening is caused by cellular material and deposits of several other substances with lipids comprising the largest part. Coronary artery disease accounts for more than 50% of all deaths in the USA. It is the number one cause of death of women. When the inner diameter of blood vessels gets smaller, blood pressure gets higher and the heart must work harder. Also, if a blood vessel is totally occluded, the tissue that receives nourishment from the blood carried by that vessel dies. This is what happens in "strokes" and "heart attacks."

Blockages in men are more likely to obstruct larger arteries, while women may have a more diffuse disease that clogs smaller vessels. That is why it is necessary for women to be alert to the slightest, briefest chest pains, especially if it radiates to the arm, neck, jaw or stomach.

The lipid profile at Crestwood Hospital consists of four tests and some calculated values. The measured tests are cholesterol, triglycerides, and HDL (high density lipoprotein). The calculated values are LDL, VLDL, and a cardiac risk factor.

Cholesterol is found almost exclusively in animals and man. It is a solid alcohol of high molecular weight. A portion of the body's cholesterol is derived from dietary intake but the majority is synthesized by the liver and other tissues. Some peoples' livers make more cholesterol than others. The National Cholesterol Education Program advises keeping cholesterol counts at less than 200 mg per deciliter. Recent studies have shown the risk for heart disease drops two to three percent for every one percent drop in blood cholesterol. If dietary changes aren't enough there are new cholesterol lowering drugs available that inhibit the body's production of cholesterol.

Triglycerides constitute 95% of tissue storage fat and are the predominant form of glycerol ester found in plasma. Triglycerides from plants generally are polyunsaturated and remain liquid at room temperature. Triglycerides from animals (especially ruminants) tend to be solid at room temperature and are more saturated. They are not as good a choice for those trying to eat a heart healthy diet. "Saturated" refers to how many oxygen-hydrogen groups that are part of the molecule. The more of these groups that make up the molecule, the more "saturated" it is, and the more likely it is to be a solid when we eat it. When triglycerides measure 150 mg/dl or more, and protective HDL (good cholesterol) levels are less than 45, the risk of heard disease climbs tenfold. It has been conjectured that the protective effect of unsaturated fats(such as olive oil and cannola oil) might be that they are scavengers of "free radicals" which cumulatively damage tissues as we age. The "free radicals" bond to the parts of the molecule that is not saturated.

HDL or high density lipoprotein are molecules made up of lipids and proteins. Lipids cannot be transported by the blood unless they are made soluble by uniting with proteins and some other compounds to form huge transportable groups. Part of these mobilizing groups is called apolipoprotein of which HDL is a part. The A group of apolipoproteins for the major part of HDL. It is advisable to keep the "good" HDL part above 35. There are even more groups of lipoproteins that can be measured or calculated by labs. One group that resembles LDL (Low Density Lipoprotein) closely has been found to be a predictor of increased risk of cerebrovascular disease. This group is called Lp(a).

The cardiac risk factor is calculated by dividing the total cholesterol by the HDL value . If this value is greater than 5 in a male or greater the 4.5 in a female the risk for heart disease is increased. As further studies are carried out, we must all watch for new ways to monitor our lipids and our health in general.

Thyroid Profile

Laboratory testing of thyroid function is usually ordered in the form of a thyroid profile which is a group of individual tests. It generally consists of measuring the amount of the hormones thyroxine (T4) and triiodothyronine (T3) produced by the thyroid gland and secreted into bloodstream. From these measurements the FTI (free thyroxine index) and T3U (triiodothyronine uptake ratio) can be computed. Measurement of one or more of the above parameters can give the physician assistance in diagnosing many illnesses or disorders in the human body.

During the production of thyroxine, two substances are taken from the blood by the thyroid gland. These are iodine as sodium or potassium iodide, and tyrosine, an amino acid. The thyroid gland combines these two into a new product called diiodo- or monoiodotyrosine. Diiodotyrosine is acted upon by thyrotropic hormone and converted into thyroxine. Thyroid hormone functions to regulate the rate at which the tissues of the body work. Thyroxine and triiodotyronine are stored in the colloid of the thyroid follicle. The molecules of these substances attach to giant protein molecules called thyroglobulin which are so large that they can't get through the wall of the follicle and escape into the blood. Thyroid hormone is released when the thyroglobulin splits.

The speed of virtually all basic cellular processes of the human body is regulated by the thyroid gland . Thyroid activity is in turn tuned by the pituitary gland . Regulation of the thyroid gland by the pituitary involves a release of thyroid stimulating hormone (TSH). The nervous system controls the thyroid gland through the action of the hypothalamus. A feedback from the thyroid itself provides a final link in the chain of controls. A high rate of production of thyroid hormone suppresses the production of TSH. On the other hand, if there is a deficiency of thyroid hormone, as occurs in some diseases of the thyroid gland , the anterior lobe of the pituitary automatically secretes additional TSH, which affects the thyroid and may result in enlargement of the gland sometimes referred to as a "goiter".

The thyroid gland is one of the most sensitive organs in the human body. During puberty, pregnancy and physiologic stress it increases in size and becomes more active as changes in activity and size occur during the menstrual cycle of the female. The secretion of thyroid hormone affects at least 20 enzyme systems in the human body.

Thyroid abnormalities usually manifest themselves in one of two ways: (1) too such production of thyroxine with an increase in metabolic rate (hyperthyroidism ); or (2) too little production of thyroid hormone with a reduction in metabolic rate (hypothyroidism). Either condition may be associated with goiter and both can be physiologically devastating.

In hyperthyroidism the patient is usually excitable and nervous with moist skin, rapid pulse, and elevated metabolic rate. Sometimes the eyes begin to protrude which is called exopthalmus. If a tracer dose of radioactive iodine is given, there is an increase in thyroidal uptake in hyperthyroidism. A doctor can choose among alternates of surgery in which he removes segments of thyroid gland, administration of radioactive iodine to destroy segments of the gland, or the use of anti-thyroid drugs to block the production of thyroid hormone when this condition occurs.

Hypothyroidism results in physical and mental sluggishness with many symptoms of a low "rate of living". If this happens in childhood, changes in body proportion and face fail to occur. The formation and eruption of the teeth are delayed, and cartilage is converted into bone as it should be during growth. The hypothyroid child exhibits a broad face with a large mouth and is usually mentally defective. They have a generally low metabolic rate and if this condition is congenital the are called "cretins". Adults with hypothyroidism show puffiness and dryness of the skin and functional changes in the heart. If the adult is a female, menstrual irregularities are common. Hypothyroidism in adults is called "'myxedema". Myxedema it is usually treated by administration of the thyroid hormone thyroxine.

As one can see, the testing of thyroid hormone levels in the blood is an essential tool in the diagnosis of various diseases and conditions of the human body.

Cardiac Enzymes

Enzymes are large protein molecules which act like catalysts, that is, they speed up the rates of intracellular chemical reaction. Cardiac enzymes are those found in the cells of heart tissue. However these enzymes are not exclusive to heart muscle. The major enzymes considered to be "cardiac enzymes" are CK (creatine kinase, sometimes called CPK, creatine phosphokinase), LD (lactate dehydrogenase), and GOT (glutamate oxaloacetate transaminase which is called AST in another nomenclature system). When heart muscle is damaged in any way these enzymes are released in to the blood stream and the levels increase from what they normally run. This is what happens after a "'heart attack" or myocardial infarction. Damage occurs when the blood supply to heart muscle is cut off by a blood clot in the arteries that supply the heart muscle. That is why a doctor will order these tests if he suspects a "heart attack" may have occurred. Normally these enzymes levels will be ordered every six hours, eight hours, or twelve hours from the onset of chest pain. This timing varies with the protocol of the hospital and how a physician was trained in medical school. The reason these tests are repeated is to see the rise and fall of the levels and to determine if further damage is occurring or whether there is damage at all.

The level of CK will peak at about 24 hours after myocardial-infarction and taper back to normal levels within three days. LD takes longer to peak after M.I., about three days, and will remain elevated up to thirteen days. AST/GOT will peak at about 48 hours and remain elevated about five days. Click here for diagram.

The CK enzyme has several forms that are called isoenzymes because they carry out the same function but are a slightly different molecule: CK-MM is found in muscle cells, CK-BB is found in brain tissue, and CK-MB is found in heart muscle. After an acute myocardial infarction CK-MB appears within four to eight hours and peaks at 24 hours. This is one of the most useful tests in diagnosing an M.I. for the physician. Recent technology has enabled CK-MB to be subdivided even further into molecules called isoforms which can be diagnostic of an M.I. in an even shorter time frame. LD has isoenzymes also. Physicians need to know whether an an M.I. has really occurred because chest pain can be caused by many other illnesses. Further damage to the heart muscle can be prevented if "clot-busting" medications are administered soon enough.

For further information on what other organs or tissues produce these same enzymes, see our listing of these individual enzymes.

TBETA HCG

Human Chorionic Gonadotropin, HCG, is a substance produced primarily by females who have become pregnant, although very small amounts can be produced in non-pregnant, healthy females. The beta part of the hCG is simply a part of the molecular structure that is different from other similar substances in the body. Beta hCG is used to determine how well a pregnancy is going. The Beta hCG in a normal pregnancy will double every 2 days for the first 8-12 weeks of pregnancy. If a doctor suspects a problem with a pregnancy in the first 8-12 weeks, a series of Beta hCG tests can be done to determine if the Beta hCG is increasing as it is suppose to. Usually if there is a problem with the pregnancy, the Beta hCG levels will not increase and may even decrease over a period of time. (Beta hCG is no longer useful in monitoring pregnancy after the first 8-12 weeks, as the levels will start to decrease.) Beta hCG can also be detected as early as 8-10 days after conception. Because of its rapid rise it is an excellent confirmatory test of early pregnancy. Elevated hCG levels can be seen in some patients with conditions not related to pregnancy. But, patient history can eliminate pregnancy in these cases.

BetahCG is measured by using various reagents, chemical solutions that are specific for the Beta hCG substance, and an instrument, or a machine, with a special light source. The instrument mixes the reagent and the patients serum/plasma, the liquid component of blood that contains the hCG substance, in tubes. The mixture is then incubated, or allowed to stand at a certain temperature for a period of time. After the incubation, the instrument uses the special light source to read the reagent\serum mixture and sends the information to the computer of the instrument. The computer then calculates a real number that can be compared with ranges of normal pregnancy. Control samples are run with each patient to make sure the instrument is working properly.

THERAPEUTIC DRUG MONITORING Therapeutic Drug Monitoring is used to monitor various groups of drugs that are administered to patients who need them. Some drug groups include: anti-inflammatory, antibiotics, antiepileptics, cardiac (heart) agents, psychoactive (psychiatric drugs), and others.

Ranges have been developed for each drug that establishes the best levels at which the drugs will be able to perform the action intended. These levels are called therapeutic ranges. Any level below the therapeutic range is considered to be inadequate for the proper action of the drug. Any level above the therapeutic range can become toxic to the patient. The effects of toxicity for each drug varies. In some rare cases, death can occur. (See examples for different toxicity effects).

Some drug levels, especially some of the antibiotics, are monitored by doing peak levels at the time when the maximum level of drug is in blood stream, and trough levels at the time just before next dose, when the drug should be at its lowest level. Peaks and troughs can be performed on hospital patients only.

Most drugs do not use the peak and trough method. They are measured either at specific times or at random times. People who take certain therapeutic drugs on a regular basis, may often have to have their drug level checked to ensure proper dosage.

Therapeutic drugs are measured using various reagents, chemical solutions that are specific for the drug being measured, and an instrument with a special light source. These instruments mix the patient's serum, the liquid part of the blood that contains the drug, and the reagents in tubes. The mixture is then incubated, allowing it to stand at a certain temperature for a period of time. After the incubation time the instrument uses its special light source to read the reagent/serum mixture and sends the information to the brain (computer) of the instrument. The computer calculates a real number that can be compared to the desired therapeutic range.

Control samples are run with each patient to ensure that the instrument is working properly.

DRUGS COMMONLY MONITORED:

Acetaminophen (Tylenol)

• Toxic Effects: Skin rash, fever.
• In overdose situations: hepatic (liver) necrosis, renal tubular (kidney) necrosis, hypoglycemic coma.

Theophylline

• Toxic effects: nausea, vomiting, diarrhea, insomnia, headache, irritability, nervousness, seizures, and sinus tachycardia (heart).

Carbamazepine (Tegretol)-

• Toxic effects: diplopia, blurred vision (6-50%), drowsiness, dizziness, slurred speech (11-50%), nausea, vomiting (<10%), skin rash (3%)
• Therapeutic range: 4-12 ug/ml
• Toxic levels: >12ug/ml

Phenobarbital

• Toxic effects: Involves the central nervous system, such as confusion and sedation in elderly people, sedation in adults, irritability and hyperactivity in children.

Phenytoin (Dilantin)

• Toxic effects: Involves central nervous system such as vertigo (dizziness), double vision, blurred speech, and coma.

Valproic Acid (Epilim, Depakene)

• Toxic effects: Most common are nausea, vomiting, diarrhea, sedation, hepatotoxicity (liver), neurological symptoms (tremors and incoordination), and coagulopathy (bleeding problems).

Amikacin

• Toxic effects: nephrotoxicity (kidney), ototoxicity (hearing loss), and neuromuscular blockade (loss of muscular control)

Gentamicin

• Toxic effects: Same as amikacin

Vancomycin

• Toxic effects: hypersensitivity, skin rashes, anaphylaxis, chills, fever, ototoxicity (hearing loss), pain at site of infection, and in rare cases, kidney damage.

Digoxin (Lanoxin)

• Toxic effects: cardiac problems, vomiting, diarrhea, nausea, neurological problems such as headaches, fatigue, and disturbance of color vision.