Talwin works to relieve pain by binding to opioid receptors throughout the body and mimicking the action of naturally occurring chemicals that block pain. The main effects occur when it binds to receptors in the central nervous system (the brain and spinal cord). However, the drug can produce effects anywhere opioid receptors are found in the body.
There are several different types of opioid receptors in the body. Talwin is classified as an opioid agonist-antagonist, which means it binds to and activates certain opioid receptors, known as kappa receptors, but also binds to and blocks certain other opioid receptors known as mu receptors.
Talwin is generally considered a relatively weak antagonist. However, as a mu opioid receptor antagonist, it can partially block the action of opioid medications that bind to mu receptors, such as morphine
, making these medications less effective. It also has the potential to cause withdrawal symptoms in people who have been taking these other opioids for extended periods. In addition, Talwin is only a partial agonist at kappa receptors, which means it only partially activates them.
Compared to full agonists, such as morphine, partial agonists-antagonists like Talwin usually have a limited effective dosing range. This means there is a maximum dose above which the drug will no longer have any further effects. This can help make Talwin a less desirable drug for abuse, and make it less dangerous than full agonist drugs, particularly in the case of an overdose.
Some general considerations to keep in mind during treatment with Talwin include the following:
- This medication comes in the form of a liquid that is given as an injection every three to four hours.
- The injections may be given into a vein (an intravenous, or IV, injection), into a muscle (an intramuscular, or IM, injection), or beneath the skin (a subcutaneous, or SC, injection).
- Talwin injections are usually given by a healthcare provider in a healthcare setting. If you will be injecting this medicine at home, make sure you know exactly how to use it before giving yourself a dose.
- For the medication to work properly, it must be used as prescribed. Do not use more of this medicine than prescribed, or stop using it suddenly, without your healthcare provider's approval.