Fentanyl – action, indications, dosage, side effects

Proven content

Fentanyl is a powerful pain reliever that can only be obtained with a prescription. It is used primarily in anesthesiology, but also as a medicine for chronic and acute pain. Fentanyl is an opioid, which means it is a very potent narcotic drug. Its active substance binds to opioid receptors in the human body, stimulating them. It is worth remembering that fentanyl has a much stronger effect than, for example, morphine, because it dissolves in fats and penetrates into the brain much more easily. Check what else is worth knowing about fentanyl.

Fentanyl – action

Fentanyl acts on μ-opioid receptors. It is an agonist of opioid receptors, the stimulation of which results in a decrease in the concentration of cAMP. As a result, the inflow of calcium ions to the cells is reduced, and then the number of sent nerve impulses, including those related to pain, is reduced. It also has a calming effect.

Fentanyl is physically dependent, induces vomiting and constipation as a consequence of increasing smooth muscle tone in the digestive system. Like other opioids, fentanyl inhibits the respiratory function.

Fentanyl – absorption

Fentanyl is rapidly absorbed from the oral mucosa. It is much less absorbed from the digestive system. The bioavailability of fentanyl after oral administration it is about 70 percent, and after administration to the skin about 92 percent. Fentanyl contained in slices penetrates the layers of the outer skin, where they quickly enter the bloodstream. Optimal blood fentanyl levels lasts for 72 hours and the patch should not be changed sooner, in order to avoid an increase in the concentration of the substance in the plasma. Increased body temperature may increase the absorption of the substance.

Fentanyl is rapidly absorbed when administered into the nose. The maximum concentration is reached after 20 minutes after administration. After administration of the drug, it forms a gel coating on the nasal mucosa, from which the active substance penetrates into the bloodstream.

Fentanyl – indications

Fentanyl is a very strong pain reliever that stimulates the action of opioid receptors. Therefore, the drug was used to treat short periods of severe pain in cancer patients who were taking other opioid medications.

Fentanyl can be obtained in various forms. These are both buccal and sublingual tablets, nasal sprays, as well as patches and ampoules. It’s good to know that fentanyl can also be given to children when they need to take large amounts of opioid medications.

Fentanyl has also been approved for the treatment of type XNUMX multi-symptomatic pain syndrome and treatment of pain associated with chronic herpes zoster neuralgia.

Fentanyl is recommended for:

1. minimizing pain after short, low-dose surgery;
2. minimizing pain or inhibiting breathing in patients requiring supportive breathing then administered in high doses;
3. induction of surgical analgesia during general anesthesia;
4. performing neuroleptoanalgesia, then it is combined with neuroleptic agents;
5. carrying out analgosedation, then it is used alone or together with other drugs;
6. relieve severe pain after an injury or during a heart attack.

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Fentanyl – dosage

Dosage of fentanyl depends mainly on the body weight and age of the patient. The co-morbidities and the stage of the underlying disease also have an influence on the determination of the dose. Treatment with fentanyl requires the doctor to have extensive experience in the use of opioids in the treatment of pain, so it is worth choosing a trusted specialist.

Before a doctor introduces fentanyl breakthrough pain into treatment, he or she sets up a chronic pain management plan. The physician must monitor the patient during dose titration, as there is a risk of respiratory depression using fentanyl.

The end of the use of the drug should be consulted with your doctor. The indication for discontinuation of fentanyl is the absence of breakthrough pain episodes. In the case of long-term use of the drug, hyperalgesia, i.e. excessive sensitivity to pain, may develop.

If we accept fentanyl in tablet form place it deep under your tongue and swallow any remaining tablets after 30 minutes. The buccal tablets should be placed immediately after removing from the packaging under the cheek, near the molar. In addition, remember to thoroughly moisturize your mouth before administering fentanyl. If there are no effects from the use of the drug, the dose should be increased according to the schedule established by the doctor. The dose should be increased when the patient experiences more than four episodes of breakthrough pain during the day.

We should also remember that liver or kidney failure is an indication to modify the fentanyl dose.

Fentanyl in the form of a nasal spray enables the administration of 100 to 3200 micrograms of the active substance per day. The interval between successive doses should be at least four hours. However, if the patient changes the form of the drug, it is necessary to readjust the dose level.

The drug can also be used in the form of transdermal patches. Thanks to this constant amount of fentanyl will be released into the human body. The dose in this case is 0,3 mg to 2,4 mg of the active ingredient. However, remember that the patches should be changed every 72 hours.

Fentanyl patches is applied to flat and hair-free surfaces of the body, and the skin should be intact. Therefore, it is best to choose the shoulders or the upper back for application. You should also make sure that the skin is dry, and you should not apply lotions or creams immediately before applying the patch.

Lek fentanyl it can also be used as an injection, but is only given in this way in hospitals. Daily dose of fentanyl ranges from 50 µg to 3500 µg. The dose depends on the intensity of the pain and the ability to control the patient’s breathing. Fentanyl can also be administered by intravenous infusion, however, doses above 200 µg can only be administered to the patient under general anesthesia. In addition, then one should bear in mind the interactions it may have fentanyl z tiopentalem and methohexytal (anesthetics).

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Fentanyl – contraindications

Contraindication to the use of fentanyl is primarily hypersensitivity to the active ingredient. FROM fentanyl therapy it should also be abandoned when there is no opioid maintenance treatment. Moreover contraindication to taking fentanyl is:

1. severe obstructive pulmonary disease;
2. respiratory depression;
3. a different type of pain than breakthrough pain.

Phenanthyl also cannot be used epidural and spinal when there are clinical limitations associated with this route of administration.

Phenanthyl – precautions

People applying fentanyl in the form of a nasal spray should pay attention to whether there is inflammation in the area of ​​the nasal mucosa, discomfort and bleeding. If such symptoms occur, another route of administration should be considered.

Keep the medicine out of the reach of children during fentanyl treatment. It should be remembered that even the smallest amounts of the active substance can lead to the death of a child who is not taking opioids. The drug is not recommended for children under two years of age. It is also not given to children who have not been given opioids before due to the risk of respiratory depression, which can lead to death.

People with a slow heart rate should be especially careful as fentanyl may further slow down the heart rate and aggravate existing arrhythmia. Caution should be exercised in patients with volume depletion and hypotension.

Fentanyl should also not be used concomitantly with inhibitors of the cytochrome p3 CYP4A450 subunit. Combining these therapies can potentiate the effects of your medications and increase your risk of developing it fentanyl side effects. For this reason, a minimum of two days between the use of drugs should be kept.

Use of fentanyllike other opioids is associated with the risk of respiratory distress. It is very important during fentanyl treatment that the patient is on a long-term treatment with other opioids as this reduces the risk of severe respiratory depression. Particular care must be taken in the case of use fentanyl in patients with respiratory diseasebecause the medicine may make their symptoms worse. Them higher dose of fentanyl, the greater the risk of respiratory impairment.

The use of fentanyl is also associated with the risk of tolerance and dependence. Most often, it is the development of tolerance at the time of drug abuse. People who are prone to abuse alcohol or other stimulants are at a much greater risk of addiction. Control can be performed. Shipment test for the presence of psychoactive substances – semi-quantitative determination, which detects the presence in the body of such substances as: fentanyl, codeine, tramadol, morphine, amphetamines, cocaine.

In addition, people who suffer from impaired consciousness or increased intracranial pressure may deteriorate their health.

In patients with fever, fentanyl patches increase the risk of an increase in the concentration of the active substance, as a result of increased body temperature. For this reason, various sources of heat, such as electric cushions or heated beds, can also pose a risk.

Fentanyl in combination with sedatives it can lead to breathing problems, severe drowsiness, coma and even death. The combination of the two drugs should therefore be kept as short as possible and the doses used should be as low as possible.

In addition, remember that the drug is prohibited for people with intestinal obstruction, as the drug substance can increase the tone of the smooth muscles of the digestive system. People using fentanyl should therefore be instructed on how to manage constipation. Liver or kidney failure may lead to a prolongation of the effect of opioids, which may be associated with a change in the amount of plasma proteins in patients with liver failure.

In the elderly, the drug has longer half-lives. They are also much more sensitive to fentanyl and the strength of the transdermal patch may need to be adjusted.

Fentanyl should also not be used concomitantly with drugs from the group of SSRIs, SNRIs and monoamine oxidase inhibitors. Combining these therapies increases the risk of developing serotonin syndrome. If you develop a sudden increase in body temperature, blood pressure disturbances, hallucinations, or coma and abnormal coordination, consult your doctor immediately and stop taking fentanyl.

Use of fentanyl in the transdermal patch also requires special care. If the patch accidentally sticks to another person’s skin, they could overdose and even die from respiratory failure. people with hypersensitivity to fentanyl. Myoclonic reactions may occur during fentanyl therapy in patients with myasthenia gravis. Therefore, caution is also advised.

Additionally, fentanyl should not be taken together with monoamine oxidase inhibitors. When these substances are combined, serotonin syndrome can occur. For this reason, a minimum two-day interval between the administration of monoamine oxidase inhibitors and fentanyl should be maintained.

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Fentanyl – interactions

When using fentanyl, grapefruit juice should not be consumed concomitantly, as it may potentiate the effects of the active substances due to the inhibition of the activity of cytochrome CYP3A4.

Alcohol may increase the effect of the active substance. In addition, alcohol increases the risk of respiratory depression and death.

As fentanyl is an opioid medicine, its active substances may have an influence on the ability to drive and use machines. Fentanyl does not have to affect every patient, but each patient should evaluate the effects of the therapy on their own body. If he develops drowsiness, disturbances in concentration or coordination, she should stop fentanyl immediately.

It should also be remembered that the use of fentanyl may result in a positive doping test result. It is not recommended to use the drug during pregnancy, as there are not many studies on the effects of the substance in fetal development. The active substance can cross the placenta into the baby’s body and cause respiratory depression, which may be fatal.

Fentanyl is also not recommended during breastfeeding. The active substance of the drug may pass into breast milk to a small extent, which may lead to breathing problems in the newborn. In addition, the baby may develop withdrawal syndrome if the mother has taken the medicine while breastfeeding. Feeding can be started only after three days from removal of the fentanyl patch, or five days after taking the last oral dose.

Fentanyl – side effects

The most common ones fentanyl side effects These include dizziness, constipation, nausea, relaxation, sleepiness and vomiting. There may also be imbalances, headaches, sweating, taste disturbances, abdominal pain, as well as accidental injuries or fractures. There may also be hypotension, abnormal thinking, restlessness, hallucinations, confusion, dry mouth, itching, changes in consciousness, weakness, myoclonus, convulsions, euphoria, rash, visual disturbances, flatulence and feeling unwell.

Rarely, paraesthesia, anorexia, impaired motor coordination, coma, intestinal obstruction, depersonalization, hyperalgesia, dyspnoea, caries, abnormal dreams, abnormal gait, depression, respiratory depression, abdominal enlargement or fever may occur.

In addition, side effects also include fever, hot flushes, peripheral edema, insomnia, diarrhea, fatigue, delirium, reddening of the skin, drug abuse, addiction, tooth loss, gum recession, and withdrawal syndrome in adults and newborns. However, the frequency of occurrence is unknown.

Fentanyl – overdose symptoms

After the party too much fentanyl symptoms of drug overdose may appear. Then the risk of side effects increases. The most dangerous symptom of fentanyl overdose there is respiratory depression, as well as cardiac arrest and other life-threatening breathing disorders. In addition, it should be remembered that if we take a higher dose than usual, it can lead to mental changes.