Drug dependence pentazocine

In 1966 the World Health Organisation Expert Committee on Dependence Producing Drugs cleared [116] pentazocine of need for restriction under narcotics... 

Brogden, R.N., Speight, T.M., Avery, G.S. Pentazocine a review of its pharmacological properties, therapeutic efficacy and dependence liability, Drugs 1973, 5, 6-91. 

Patients who have received hydromorphone for long periods of time or those with confirmed opioid dependency should not receive the so-called agonist/antagonist analgesics, such as nalbuphine, pentazocine, butorphanol, dezocine, and buprenorphine. The use of these drugs in these patients can intensify withdrawal symptoms. 

Drugs that bind strongly to red blood cells may exhibit concentration-dependent uptake from plasma. This is reported for acetazolamide, chlorthali-done, and cyclosporine. " The determination of the blood to plasma (B/P) ratios can be method specific. For example, the determination of the B/P ratio of cyclosporine A increases from 1.5-3.0 when estimated at body temperature (37°C) compared with a ratio of 2.5-10.0 at room temperature (20°C). Drugs reported to bind strongly to the erythrocytes (B/P ratio > 1) are promazine, chlorpromazine, propranolol, salicylate, phenobarbital, pentazocine, and phenytoin. " ... 

Psychological and physical dependence may occur. Tolerance may develop, resulting in the need for higher and more frequent dosing. Some oral pentazocine preparations also contain naloxone (an opioid antagonist) to reduce parenteral abuse. Naloxone does not affect the efficacy of pentazocine administered by the oral route naloxone does inhibit pentazocine s opioid effect if tablets are solubilized and injected. Pentazocine may be abused as a heroin alternative or in combination with other drugs. The most publicized combination was T s and Blues ... 

In later investigations (1966) the impression that cyclazocine was not suitable as an analgetic was confirmed, but its use for the treatment of narcotic addicts was still favoured. The possibilities for pentazocine looked much brighter, and in 1967 pentazocine was released by the American Food and Drug Administration however, at very high doses some incidence of psychomimetic activity was observed. More recent investigations have demonstrated that, parenterally, the respiratory depression caused by pentazocine is equal to that shown by morphine, and also the absence of addictive properties has been questioned. Prolonged administration of pentazocine produces dependence like morphine. 

The total dose required to reverse the effects of the opioid is highly variable and is dependent on the concentration and receptor affinity of the opioid. Some drugs (eg, propoxyphene, diphenoxylate/atropine [Lomotil], buprenorphine, pentazocine, and the fentanyl derivatives) do not respond to usual doses of naloxone. However, if no response is achieved by a total dose of 10-15 mg, the diagnosis of opioid overdose should be questioned. 

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