Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (988 page)

Decreased In

   Schizotypal personality disorders

   Limitations

   Preferred specimen is 24-hour urine, because of intermittent excretion.

   Moderately elevated HVA may be caused by a variety of factors such as essential hypertension, intense anxiety, intense physical exercise, and numerous drug interactions (including some over-the-counter medications and herbal products).

   Medications that may interfere include amphetamines and amphetamine-like compounds, appetite suppressants, bactrim, bromocriptine, buspirone, caffeine, chlorpromazine, clonidine, disulfiram, diuretics (in doses sufficient to deplete sodium), epinephrine, glucagon, guanethidine, histamine, hydrazine derivatives, imipramine, levodopa (
L
-dopa, Sinemet), lithium, MAO inhibitors, melatonin, methyldopa (Aldomet), morphine, nitroglycerin, nose drops, propafenone (Rythmol), radiographic agents, rauwolfia alkaloids (Reserpine), and vasodilators. The effects of some drugs on catecholamine metabolite results may not be predictable.

HUMAN CHORIONIC GONADOTROPIN (hCG)

   Definition

   Glycoprotein hormone, which is also known as β-hCG and chorionic gonadotropin, is produced by the placenta, with structural similarity to the pituitary hormones FSH, TSH, and LH. The hCG test is widely used to detect pregnancy. It is also used as tumor marker for choriocarcinoma and some germ cell tumors.

   
Normal range:
≥5.0 mIU/mL (generally indicative of pregnancy; Table 16.40).

TABLE 16–40. Representative Ranges in Human Chorionic Gonadotropin (hCG) During Normal Pregnancy

   Use

   Diagnosis of pregnancy

   Investigation of suspected ectopic pregnancy

   Monitoring in vitro fertilization patients