How buprenorphine works
As an opioid active ingredient, buprenorphine does not occur naturally in the poppy plant like the opiates, but is chemically-pharmacologically modeled on them. Thanks to the targeted modification of the structure, opioids are more beneficial than opiates in terms of effect and side effects.
Like opiates, opioids such as buprenorphine exert their effect via opioid docking sites (receptors) in the central nervous system, i.e. in the brain and spinal cord. They mainly mediate an analgesic effect via these sites. Their effect at the receptors is usually stronger than that of the body’s own endorphins, which also dock there.
The standard active ingredient with which all other opiates and opioids are compared in terms of potency is the opiate morphine, which is also used in pain therapy. Compared with this, the active ingredient buprenorphine has a potency that is about 25 to 50 times greater.
In contrast to the other active ingredients, it exhibits a so-called “ceiling effect” with regard to respiratory depression, for example: Thus, above a certain dosage, respiratory depression does not become even stronger with further dose increases, as is the case with morphine, for example.
In addition, buprenorphine is not a so-called full agonist (where the effect increases more and more with increasing dosage), but a partial agonist, which comes to a certain percentage of effect, but not beyond – even in combination with other opioids.
This effect is especially important for addiction withdrawal, as it can effectively relieve withdrawal symptoms but avoid dose increases and overdoses.
Absorption, breakdown and excretion
When buprenorphine is administered through the mucous membranes (as a sublingual tablet), it reaches peak blood levels after about one and a half hours.
In addition, the active ingredient can also be administered directly into the blood, which is the fastest way for it to exert its effect.
About two-thirds of buprenorphine is excreted unchanged in the bile via the intestines, and one-third is broken down in the liver and excreted in the urine.
When is buprenorphine used?
Buprenorphine is used to treat severe and very severe pain (such as pain after surgery, heart attack pain, and tumor pain) and in combination with addiction treatment for substitution therapy in opioid addicts.
For the treatment of addicts who have consumed opioids intravenously, there are also combination preparations with the active ingredient naloxone. This is intended to prevent the buprenorphine sublingual tablets from being misused (by dissolving and injecting).
How buprenorphine is used
The dosage depends on the intensity of the pain and must be determined by the doctor. Usual dosages are 0.2 to 0.4 milligrams of buprenorphine every six to eight hours, i.e. three to four times a day.
Buprenorphine patches are applied for several days (varies by manufacturer – usually three to four days, sometimes up to seven days) and continuously release the active ingredient through the skin into the body. This dosage form is often chosen for longer-term therapy.
When changing patches, care must be taken to ensure that no buprenorphine-containing residue from the patch remains adhered to the skin. The new patch must be applied to a new, suitable skin site. This must be clean, but may only be cleaned with water. Oils, disinfectants, etc. can influence the release rate of the active substance from the patch.
Follow the steps described in the package insert for proper disposal of used buprenorphine patches.
What are the side effects of buprenorphine?
Taking buprenorphine is associated with side effects similar to those of other opioids. More than ten percent of patients experience nausea, headache, insomnia, increased sweating, weakness and withdrawal symptoms.
In addition, one in ten to one hundred people treated experience side effects in the form of inflammation of the respiratory tract, loss of appetite, restlessness, anxiety, depression, drowsiness, dizziness, tremor, changes in heart rhythm, drop in blood pressure, shortness of breath, indigestion, constipation, vomiting, rashes, joint, bone and muscle pain.
The aforementioned side effects are more common at high doses, such as those used for addiction treatment.
What should be considered when using buprenorphine?
Contraindications
Buprenorphine must not be used in:
- Hypersensitivity to the active substance or to any of the other components of the drug.
- concomitant use of antidepressants from the group of monoaminooxidase inhibitors (MAO inhibitors) and up to 14 days after discontinuation of this therapy
- Myasthenia gravis (pathological muscle weakness)
- Delirium tremens (delirium that occurs during alcohol withdrawal)
Drug Interactions
If buprenorphine is taken with other substances that depress the central nervous system, excessive sedative, depressant, and soporific effects may occur.
Such substances include sedatives and sleeping pills from the benzodiazepine group (such as diazepam, lorazepam), other painkillers, older anti-allergic drugs (such as doxylamine, diphenhydramine), antipsychotics (such as haloperidol, chlorpromazine, olanzapine), and alcohol.
Examples of potent enzyme inducers include agents for epilepsy and convulsions (such as carbamazepine, phenytoin, phenobarbital) and the antibiotic rifampicin.
Driving and operating heavy machinery
Even when used as directed, buprenorphine has a pronounced effect on the ability to drive and operate heavy machinery. This is especially the case at the beginning of treatment.
Stable patients without symptoms, however, can drive a motor vehicle and operate machinery after an appropriate adaptation period.
Age Limitation
Safety and efficacy of buprenorphine in children and adolescents under 18 years of age have not been established.
Pregnancy and lactation
This can lead to “floppy infant syndrome”, whereby the newborn or infant shows hardly any body tension, reacts little to its environment and breathes shallowly, which can sometimes be life-threatening.
The technical information advises against the use of buprenorphine during breastfeeding, as the active ingredient passes into breast milk. However, according to experts, breastfeeding is allowed if the mother is well monitored and has already been stably adjusted to buprenorphine during pregnancy. When readjusting during breastfeeding, the dosage is determined individually.
How to obtain medication with buprenorphine
Preparations containing buprenorphine are classified as narcotics (Germany and Switzerland) or addictive drugs (Austria) and may only be prescribed by a specialist doctor on a special narcotic or addictive drug prescription.
Since when is buprenorphine known?
Since patent protection has now expired, numerous generics with the active ingredient buprenorphine exist today.