if someone has been using opioids. That result supports classifying pentazocine as an opioid, but in humans nalorphine does not cause pentazocine withdrawal—a result consistent with pentazocine not being an opioid. Pentazocine withdrawal is normally likened to a light version of the opiate withdrawal syndrome, although case reports tell of some persons suffering intense physical discomfort for up to two weeks (cramping muscles, painful abdomen and back, nausea, itching, sweating, and general discomposure). Debate exists about whether pentazocine addiction should be treated by substituting other drugs such as methadone or whether treatment should avoid substitution altogether. Some authorities have wondered if pentazocine addiction occurs in persons who are not polydrug abusers. Some authorities even question whether pentazocine addiction exists, noting cases in which body fluid testing contradicted drug users' claims to be using the drug (while indicating they were using other substances). German researchers found that addiction reports are at least exaggerated; upon investigation, only 8 of 60 reports turned out to be authentic.
Drug interactions. Persons who smoke or who live in a polluted air environment may need higher doses of pentazocine than persons who breathe clean air. Morphine and pentazocine boost each other's pain-relieving action. Alcohol and possibly monoamine oxidase inhibitors (found in some antide-pressants) may react badly with pentazocine.
Cancer. Animal research has not shown pentazocine to cause cancer.
Pregnancy. Normal production of litters has occurred when pentazocine was given to pregnant rats and rabbits, and no birth defects were apparent. The drug is absorbed by the fetus if a pregnant woman takes a dose. Examination of one hospital's records of all pregnant patients who used pentazocine illicitly in a two-year period showed that their infants tended to be premature and undersized, but no malformation was attributed to the drug. Newborns were occasionally dependent. Despite those disadvantages the children seemed to develop normally in their first year of life. When pentazocine was given simply as a pain reliever in childbirth, examination of the infants revealed no difference from children born to women who did not receive a medical dose of the drug during childbirth.
A study found Ts & Blues mothers to have an increased rate of assorted diseases that would not promote healthy fetal development: hepatitis, anemia, gonorrhea, syphilis. Such afflictions indicate a risk-taking lifestyle in which prenatal care is a small concern. A survey of maternity records at one hospital showed that pregnant women who used Ts & Blues tended to produce smaller infants, but no major birth defects were associated with the drug combination. Another study found behavioral abnormalities in newborns that had fetal exposure to Ts & Blues, although the conduct may simply have been a temporary sign of drug withdrawal. Investigators running a rat experiment, however, noted long-term behavioral differences between a group of rats having fetal exposure to the drug combination and another group that was unexposed.
Additional scientific information may be found in:
Brogden, R.N., T.M. Speight, and G.S. Avery. "Pentazocine: A Review of Its Pharmacological Properties, Therapeutic Efficacy and Dependence Liability." Drugs 5 (1973): 6-91.
Debooy, V.D., et al. "Intravenous Pentazocine and Methylphenidate Abuse during Pregnancy. Maternal Lifestyle and Infant Outcome." American Journal of Diseases of Children 147 (1993): 1062-65.
"Pentazocine." British Medical Journal 2 (1970):409-10.
Saarialho-Kere, U., M.J. Mattila, and T. Seppala. "Parenteral Pentazocine: Effects on Psychomotor Skills and Respiration, and Interactions with Amitriptyline." European Journal of Clinical Pharmacology 35 (1988): 483-89.
Showalter, C.V. "T's and Blues: Abuse of Pentazocine and Tripelennamine." Journal of the American Medical Association 244 (1980): 1224-25.
Zacny, J.P., et al. "Comparing the Subjective, Psychomotor and Physiological Effects of Intravenous Pentazocine and Morphine in Normal Volunteers." Journal of Pharmacology and Experimental Therapeutics 286 (1998): 1197-207.
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