What is Fentanyl?

Fentanyl is a synthetic opioid used to treat severe pain, for example during and after surgery, and in some patients with cancer pain or other severe persistent pain who are already used to opioids. It is generally used as an adjunct to regional or general anaesthesia. It is much more potent than morphine, with a clinical potency of about 50 to 100 times that of morphine, so it is used when other pain medicines are not enough and only under close medical supervision.

At a Glance

How Fentanyl Works

Fentanyl binds to opioid receptors in the brain, spinal cord and other organs, changing how the body perceives and responds to pain. It also causes drowsiness and slows breathing. Because opioids can produce effects that people seek for non-medical reasons, fentanyl has a high potential for misuse and addiction.

When to Use Fentanyl

• Surgery and anaesthesia: The injection is used as part of general or regional anaesthesia and for pain control in the immediate recovery period after surgery. It is given only by trained healthcare professionals.
• Cancer pain: Fentanyl forms absorbed through the mouth or nose are used for breakthrough cancer pain (sudden pain flares) in adults who are already taking and are tolerant to around-the-clock opioid treatment. Fentanyl patches are used for severe, persistent pain in opioid-tolerant patients when other options are not enough.
• Intensive care: In hospital, it is given by injection or infusion for pain relief in some patients who need assisted ventilation.
• Not for everyone: Patches and mouth-absorbed forms must not be used for short-term pain, pain after surgery, headache or migraine, or in anyone who is not already opioid-tolerant.

Dosage

Fentanyl doses are individualized by a specialist and depend on the form used, the reason for treatment, age, weight, kidney and liver function, other medicines, and whether the patient is opioid-tolerant. Different fentanyl products are not interchangeable, and doses must never be converted between products by patients or caregivers.

• Injection and infusion: Given into a vein or muscle only in a setting where breathing can be monitored and supported. Doses vary widely with the procedure and the patient.
• Skin patch: Each patch is worn for 72 hours. It is only for opioid-tolerant patients, for example those taking at least 60 mg of oral morphine a day, or an equivalent dose, for a week or longer. It must never be a person’s first opioid.
• Mouth or nose forms (tablets, lozenges, sprays): Only for breakthrough cancer pain in opioid-tolerant adults. Treatment starts with the lowest dose and is adjusted by the doctor. These products cannot be swapped dose-for-dose with other fentanyl products.
• Children: Dosing is based on the child’s weight and condition and is set by a specialist. Patches may be used in children only if they are 2 years or older and already opioid-tolerant, and the safety of the injection in children under 2 has not been established.
• Older adults, kidney or liver problems: Lower doses and closer monitoring are generally needed.

Use fentanyl only as prescribed. Do not start, stop, change or share doses on your own.

Side Effects

• Common: Drowsiness and sedation, dizziness, constipation, nausea, vomiting and itching.
• With the injection: Low blood pressure, slow heartbeat and muscle stiffness can occur and are managed by the hospital team.
• Get emergency help immediately for:
  • slow, shallow or stopped breathing, or extreme sleepiness or unresponsiveness (respiratory depression)
  • agitation, hallucinations, fast heartbeat, fever, muscle rigidity or diarrhea after starting fentanyl with other medicines (possible serotonin syndrome)
  • swelling of the face or throat, or severe rash (serious allergic reaction)
• Tell your doctor about: Seizures, increased sensitivity to pain, or long-lasting fatigue, weakness and dizziness.

Precautions

• Addiction and misuse: Fentanyl can cause dependence and addiction, even when used as prescribed. Never take it unless it is prescribed for you, and never give it to anyone else.
• Breathing: The risk of life-threatening slowed breathing is highest when starting treatment or increasing the dose, and in older, frail or debilitated patients and those with lung disease such as COPD.
• Accidental exposure: Even one patch or dose can be fatal to a child or another adult. Keep all fentanyl products out of reach and dispose of used patches as instructed.
• Heat and patches: Avoid heating pads, electric blankets, hot baths, saunas and similar heat on or near a patch, as heat can increase absorption and has caused fatal overdoses. Tell your doctor if you develop a fever.
• Alcohol and sedatives: Do not drink alcohol or take sleeping tablets, sedatives or other opioids unless your doctor says it is safe.
• Driving: Fentanyl can impair your ability to drive or use machinery.
• Stopping treatment: Do not stop suddenly after regular use, because withdrawal can occur. Your doctor will reduce the dose gradually.
• Overdose: Signs include very slow or shallow breathing, extreme drowsiness and pinpoint pupils. This is an emergency. Naloxone can reverse the effects, but fentanyl may last longer than naloxone, so medical monitoring is still needed.
• Tell your doctor if you have breathing problems, head injury or raised pressure in the head, kidney or liver disease, seizures, gallbladder or pancreas problems, or a history of substance misuse.
• Allergy: Fentanyl must not be used if you are allergic to it.

Pregnancy and Breastfeeding

• Pregnancy: There is not enough data to establish the risk of birth defects. Fentanyl crosses the placenta, is not recommended during or immediately before labour, and regular use in pregnancy can cause withdrawal symptoms in the newborn. Your doctor will weigh the benefits and risks.
• Breastfeeding: Fentanyl passes into breast milk and can cause sleepiness and breathing problems in the baby. Prescribing information differs, with some advising against use and others advising close monitoring of the infant, so talk to your doctor.

Drug Interactions

• Alcohol, benzodiazepines and other sedating medicines (including other opioids, sleeping tablets and some muscle relaxants): Can cause profound sedation, slowed breathing, coma and death.
• CYP3A4 inhibitors such as erythromycin, ketoconazole, ritonavir, fluconazole, voriconazole and grapefruit juice: Can raise fentanyl levels and cause dangerous breathing problems.
• CYP3A4 inducers such as rifampicin, carbamazepine and phenytoin: Can lower fentanyl levels and reduce pain relief. Stopping one of these can raise fentanyl levels.
• MAO inhibitors and serotonergic medicines: Fentanyl is not recommended with MAO inhibitors, or within 14 days of stopping them. Some products list this as a contraindication. Antidepressants such as SSRIs and SNRIs, tramadol and triptans can raise the risk of serotonin syndrome.
• Buprenorphine, pentazocine, butorphanol and nalbuphine: These should generally be avoided with fentanyl because they can reduce its effect or cause withdrawal.

Tell your doctor or pharmacist about all prescription medicines, OTC medicines, supplements and herbal products you take. This list is not complete.

Brands and Availability in India

Common Brands in India: Fenstud and Fentanest (injection) and Fentaderm (patch). International brand names include Sublimaze and Duragesic.

Fentanyl injection in India is commonly available as 50 mcg/mL in 2 mL and 10 mL ampoules, and patches are available in different release strengths. Fentanyl is a controlled narcotic drug in India, regulated under the NDPS Act and notified as an essential narcotic drug for medical and scientific use. It is supplied only through authorised channels on a valid prescription. Prices are not listed because it is mainly supplied through hospitals and authorised pharmacies.

How HealthPil Can Help

HealthPil can help connect you to pain management specialists. Medicines should be started, adjusted, or stopped only under the guidance of a qualified healthcare professional. If you have questions about this medicine, its side effects, or your treatment plan, you can consult a doctor through HealthPil.