Pentazocine is an opioid analgesic prescribed to treat moderate to severe pain. The narcotic drug was first developed in 1967 but became a favorite illicit street drug because of its ability to induce a reaction similar to heroin. To lessen its morphine-like physical effects, the drug was mixed with the narcotic antagonist naloxone. Naloxone works by counteracting the narcotic effects of pentazocine when it is injected or dissolved. Users do not experience the narcotic opiate-induced effects of sedation, hypotension and respiratory depression that opiates generally induce.
Pentazocine works by changing how the brain and nervous system react to pain. The drug can be habit-forming and should not be taken for longer than prescribed or in a higher dose. Extended use of the drug tends to lessen its effectiveness.
The base drug of pentazocine is benzomorphan. Pentazocine is often used in conjunction with tramadol to treat post-operative pain. It is also used in conjunction with anesthesia during surgery. The drug was first developed by the Sterling Drug Co.
The medication can be prescribed orally but is also given as an injection. The injection is administered under the skin, into a vein or into the muscle. A doctor, nurse or healthcare professional usually administers injections but, in some cases, the patient may be taught how to self-administer the pain reliever at home. Injecting the medication into the same location each time may result in damage to the skin, underlying tissue, or muscle.
Users are advised not to stop the use of pentazocine suddenly, because they could suffer adverse withdrawal effects. A feeling of restlessness, runny nose, anxiety, stomach pain and fever are common withdrawal symptoms. Central nervous system problems have been noted as a side effect for some patients. The cause is unclear, but users may suffer hallucinations, cranial pressure, dizziness, disorientation, insomnia, headache and convulsions.
More common side effects include drowsiness, nausea, vomiting, redness at the injection site, constipation, and a general feeling of well-being. Serious side effects include difficulty urinating, trouble sleeping, swelling of the face, throat or tongue, tightness in the chest and shortness of breath or difficulty breathing. Some preparations of pentazocine contain sulfite preservatives, which could lead to an allergic reaction in some patients. In the United States, the drug holds the classification of a Schedule IV drug under the Controlled Substance Act. Elsewhere in the world, it is considered a Scheduled III drug under the United Nation's Convention on Psychotropic Substances.