Opiates such as heroin, morphine and codeine (methyl - morphine), are central nervous system (CNS) depressants. Morphine is an active ingredient in both opium as well as in heroin. It is used as an analgesic and sedative. Morphine is readily absorbed from an oral dose, intramuscular and subcutaneous injection. The use of opiates at high doses produce pulmonary edema, cardiac and/or respiratory failure, euphoria, hypothermia and coma. Large doses of morphine can produce higher tolerance levels, thus causing physiological dependency in users, which may lead to substance abuse. Morphine is excreted unmetabolized, and is also the major metabolic product of codeine and heroin. Thus, the presence of morphine (or the metabolite, morphine glucoronide) in the urine indicates heroin, codeine and/or morphine use. The half-life of morphine is 1.5 to 7 hours. This test detects the presence of morphine in human urine specimens, qualitatively.