Physical dependence, difference from addiction

The barbiturates also cause a physical dependence different from the opioid narcotics. In an individual addicted to barbiturates, the barbiturates should not be withdrawn abruptly but, rather, tapered slowly. Sudden withdrawal of the barbiturates can precipitate extreme agitation and grand mal seizures. This can lead to a spasm of the respiratory musculature, producing impaired respiration, cyanosis, and possibly, death (42). As a rule, drug dependence is followed by tolerance, in which increasing doses are required to obtain the same pharmacological effect. Because barbiturates cause tolerance and, often, dependence, their use as a hypnotic rarely is justified. 

PHYSICAL DEPENDENCE A condition that may occur after prolonged use of an opiate, but differing from addiction because the user is dependent on the drug for pain relief, rather than emotional or psychological relief. 

Addiction Liability. The addiction liability of WIN 20,228 was studied by Fraser and Rosenberg (3) at the Addiction Research Center at Lexington, Ky. The compound was administered both subcutaneously and intravenously to nontolerant postaddicts, who reported that the subjective effects were not morphine-like. When substituted for morphine in morphine-dependent subjects, WIN 20,228 did not suppress the abstinence syndrome of morphine. Chronic administration of WIN 20,228 was disliked by postaddicts. One subject who continued taking the compound for 25 days exhibited a mild abstinence syndrome, but no physical dependence could be demonstrated when nalorphine was administered. These effects were considerably different from those associated with morphine and it was concluded that WIN 20,228 had minimal addiction liability. 

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