Pentazocine

Pentazocine (Talvin):

Other names: talvin, fortral, lexir.

An attempt to find an effective painkiller that does not cause addiction led to the creation of Pentazocine (talvin). Introduced in 1967 as an analgesic, it quickly appeared on the illegal market, usually in combination with tripennamine. The list of narcotic drugs subject to control in the Russian Federation is in list II. An attempt to lower the level of use of this drug was made with the introduction of Talvin Nx. This product contains a certain amount of a counteracting substance to neutralize effects similar to morphine, if the tablets are dissolved and then taken orally.

Pentazocine is a synthetic opioid from the benzomorphan group. Its analgesic properties are associated with the levorotatory isomer of this drug.

Pentazocine causes respiratory depression. Among mixed agonist-antagonists, it has the maximum ability to suppress breathing and cause analgesia. When the dose of the drug is higher than 30 mg, there is no proportional increase in respiratory depression. In an adult with a body weight of 70 kg, the maximum effect occurs at a dose of 60 mg. Pentazocine does not cause hypotension and bradycardia, however, there is evidence of a moderate hyperdynamic effect with intravenous administration of 30 mg (increased blood pressure and pressure in the small circle, tachycardia). The effect of Pentazocine on the pressure in the biliary tract is weakly expressed. The danger of developing addiction is small, but sometimes physical dependence and drug addiction appear. Pentazocine is able to accelerate the development of withdrawal syndrome in people with physical dependence on opioids.

Pentazocinee lactate is released in a solution for injection at a concentration of 30 mg / ml. for oral administration, they are released in tablets with acetylsalicylic acid (12.5 mg of Pentazocine and 325 mg of acetylsalicylic acid) or with naloxone (50 mg of Pentazocine and 0.5 mg of naloxone). The dose of Pentazocine for adults is 30 mg / m or 50 mg every 3-4 hours enterally. At a dose of 50 mg, Pentazocine has an analgesic effect equivalent to 60 mg of codeine.

Pharmacokinetics

Pentazocine is well absorbed with enteral and parenteral administration. After oral administration, the biological effect has no more than 20% of the administered dose of the drug due to intensive metabolism in the liver.

During metabolism, inactive glucuronides are formed, which are excreted in the urine together with 5-25% of the unchanged drug.

Pharmacological action

Pentazocine causes analgesia as well as psychomimetic and dysphoric effects.

With parenteral administration, Pentazocine is 2-3 times weaker than morphine. The drug also causes sedation and sweating. High doses of Pentazocine provoke hallucinations and psychomimetic effect (“active anxiety”, depersonalization, etc.).

Pentazocine causes respiratory depression.Among mixed agonist-antagonists, it has the maximum ability to suppress breathing and cause analgesia. When the dose of the drug is higher than 30 mg, there is no proportional increase in respiratory depression. In an adult with a body weight of 70 kg, the maximum effect occurs at a dose of 60 mg. Pentazocine does not cause hypotension and bradycardia, however, there is evidence of a moderate hyperdynamic effect with intravenous administration of 30 mg (increased blood pressure and pressure in the small circle, tachycardia). The effect of Pentazocine on the pressure in the biliary tract is weakly expressed. The danger of developing addiction is small, but sometimes physical dependence and drug addiction appear. Pentazocine is able to accelerate the development of withdrawal syndrome in people with physical dependence on opioids.

Among mixed agonist-antagonists, it has the maximum ability to suppress breathing and cause analgesia. When the dose of the drug is higher than 30 mg, there is no proportional increase in respiratory depression.

In an adult with a body weight of 70 kg, the maximum effect occurs at a dose of 60 mg.

The danger of developing addiction is small, but sometimes physical dependence and drug addiction appear. Pentazocine is able to accelerate the development of withdrawal syndrome in people with physical dependence on opioids.

Use in the clinic

Pentazocine can be used as an antagonist of morphine (fentanyl). The administration is carried out 10-15 minutes before the end of the operation: Pentazocine (1 mg / kg) is injected slowly (for 2-3 minutes); it is advisable to first introduce half of the calculated dose, and after 3-4 minutes – the remaining part.

The effect of awakening and restoring independent breathing occurs after 3-4 minutes. Reducing respiratory depression associated with the use of fentanyl, Pentazocine with intravenous administration itself leads to it, although the duration of depression is much shorter.

The dose of Pentazocine for adults is 30 mg / m or 50 mg every 3-4 hours enterally. At a dose of 50 mg, Pentazocine has an analgesic effect equivalent to 60 mg of codeine.