What is propoxyphene?

Propoxyphene It is an opioid medication structurally related to methadone. Opioid medications provide a very high analgesic effect and this is why they are used to relieve mild to moderate pain of teeth, head, back, bones or in the cases of arthralgia, myalgia or migraines.

It is important to mention that both propoxyphene and other medications of this therapeutic family they can trigger a tolerance effect on the person who consumes it. This fact forces both the dose and the frequency of administration of this type of medication to be increased.

How does propoxyphene trigger the analgesic effect in the body?

Propoxyphene, as Opioid medications provide the analgesic effect by binding to opioid receptors, They are found both inside and outside the central nervous system. Among these receptors are μ, κ and δ.

All these receptors are associated with G proteins and they act as positive or negative modulators of synaptic transmission, which takes place through these proteins.

This therapeutic family antagonizes κ receptors by closing potassium channels that are voltage-dependent and opening calcium-dependent channels. Thus, hyperpolarization is generated and a reduction in neuronal excitability.

Opioid drugs do not alter the pain threshold of nerve endings, nor do they affect the transmission of impulses along the peripheral nerves; What they do is modify the perception of pain. Like the other opioids, the analgesic ceiling of propoxyphene is very high; You could even say you don't have.

Pharmacokinetics: what happens to propoxyphene in the body?

Pharmacokinetics includes the processes of absorption, distribution, metabolism and elimination of a medicine. In this sense, propoxyphene is a medicine that, once administered orally, is absorbed mainly in the upper small intestine. Once absorbed, reaches its maximum plasma concentrations after 2-3 hours after administration

For distribution, it requires the binding of plasma proteins. Specific, binds to these proteins in 70-80%. This fact is important to keep in mind as it favors interaction with other medications that also need these proteins for distribution.

If administered together, propoxyphene can be displaced and the percentage that is not bound to this molecule, and that is the one that performs the action, increases considerably. Due, a toxic picture of this opioid can be triggered.

After distribution, it is mainly metabolized in the liver, giving rise to a main metabolite: norpropoxyphene, which is also pharmacologically active. Finally, once metabolized, both the metabolites and the fraction of drug that remain un metabolized are excreted in the urine.

The elimination half-life of this medicine ranges from 6 to 12 hours. This term refers to the time needed to eliminate half of the plasma concentration in the body. The elimination half-life of both propoxyphene and active metabolite increases considerably in elderly patients.

Read also: Non-opioid non-opioid analgesics

Adverse reactions of propoxyphene

Like all medications on the market, andPropoxyphene is not exempt from producing a series of adverse effects. We understand adverse effects as all those events that occur undesirably and unintentionally in treatment with a medication.

In this regard, the following should be mentioned notified reactions Once the medication was marketed they are:

  • Cardiac disorders, such as arrhythmia, bradycardia or congestive heart failure.
  • Hypersensitivity
  • Psychiatric disorders: hallucinations, changes in mental state or confusion.
  • Respiratory problems, such as respiratory depression or dyspnea.

In addition, as we have commented at the beginning of the article, Propoxyphene triggers an important tolerance chart, as well as a dependence similar to that of morphine. These effects have been studied in clinical trials.

Therefore, it is essential not to abuse this type of medicine and always follow medical recommendations. Likewise, an abrupt withdrawal of propoxyphene can trigger an important withdrawal syndrome that causes serious health consequences.

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Propoxyphene is a medication that has a very potent analgesic effect and belongs to the family of opioid drugs. Like the rest of the substances in this therapeutic family, Propoxyphene produces dependence and tolerance in the patient who is treated with it.

Therefore, you should never self-medicate or abuse these substances. Misuse of medications can have fatal consequences for the person involved. You can ask both the doctor and the pharmacist any questions you have about this medicine.