Patient Leaflet Updated 02-Jun-2026 | hameln pharma ltd
Alfentanil 5 mg/ml solution for injection
Alfentanil 5 mg/ml solution for injection
This medicine contains alfentanil which is an opioid, which can cause addiction.
You can get withdrawal symptoms if you stop receiving it suddenly.
The name of your medicine is Alfentanil 5 mg/ml solution for injection, which will be referred to as Alfentanil throughout this leaflet.
1. What Alfentanil is and what it is used for
2. What you need to know before you are given Alfentanil
3. How Alfentanil is given to you
4. Possible side effects
5. How to store Alfentanil
6. Contents of the pack and other information
Alfentanil belongs to a class of medicines called opioids, which relieve or prevent pain. Alfentanil is a strong painkiller which has a very rapid effect. Alfentanil is used for surgical procedures.
Artificially ventilated patients may remain awake if they have appropriate pain control.
This medicine has been prescribed to you. Opioids can cause addiction and you may get withdrawal symptoms if you stop receiving it suddenly. Your prescriber should have explained how long you will be receiving it for and when it is appropriate to stop, how to do this safely.
Alfentanil should not be given during labour or before the cord is clamped during Caesarean section.
Talk to your doctor or nurse before you receive Alfentanil if you:
This medicine contains alfentanil which is an opioid medicine. Repeated use of opioid painkillers may result in the drug being less effective (you become accustomed to it). It may also lead to dependence and abuse which may result in life-threatening overdose. If you have concern that you may become dependent on Alfentanil, it is important that you consult your doctor.
Receiving this medicine regularly, particularly for a long time, can lead to addiction. Your prescriber should have explained how long you will be receiving it for and when it is appropriate to stop, how to do this safely.
Rarely, increasing the dose of this medicine can make you more sensitive to pain. If this happens, you need to speak to your prescriber about your treatment.
Addiction can cause withdrawal symptoms when you stop receiving this medicine. Withdrawal symptoms can include restlessness, difficulty sleeping, irritability, agitation, anxiety, feeling your heartbeat (palpitations), increased blood pressure, feeling or being sick, diarrhoea, loss of appetite, shaking, shivering or sweating. Your prescriber will discuss with you how to gradually reduce your dose before stopping the medicine. It is important that you do not stop receiving the medicine suddenly as you will be more likely to experience withdrawal symptoms.
Opioids should only be used by those they are prescribed for. Do not give your medicine to anyone else.
Receiving higher doses or more frequent doses of opioid, may increase the risk of addiction. Overuse and misuse can lead to overdose and/or death.
Your doctor will carefully monitor the amount of Alfentanil you are given.
Alfentanil is not recommended for use in children in intensive care.
The initial dose of Alfentanil should be appropriately reduced in elderly and debilitated patients.
Concomitant use of Alfentanil and sedative medicines such as benzodiazepines or related drugs increases the risk of drowsiness, difficulties in breathing (respiratory depression), coma and may be life-threatening. Because of this, concomitant use should only be considered when other treatment options are not possible.
The concomitant use of opioids and drugs used to treat epilepsy, nerve pain or anxiety (gabapentin and pregabalin) increases the risk of opioid overdose, respiratory depression and may be life-threatening.
However, if your doctor does prescribe Alfentanil together with sedative medicines the dose and duration of concomitant treatment should be limited by your doctor.
Please tell your doctor about all sedative medicines you are taking, and follow your doctor’s dose recommendation closely. It could be helpful to inform friends or relatives to be aware of the signs and symptoms stated above. Contact your doctor when experiencing such symptoms.
Tell your doctor or nurse if you are taking, have recently taken, or might take any other medicines, including medicines you can get without a prescription. This is especially important with the following medicines as they may interact with your Alfentanil:
The effects of Alfentanil may last longer if you are taking:
The effects of Alfentanil or any of these medicines may be increased when they are taken together
Your doctor may have to change the amount of Alfentanil or the other medicines you are given.
Certain medicines may affect the way Alfentanil works
Your doctor may have to change the amount of Alfentanil you are given.
Tell your doctor or nurse if you use alcohol regularly, because the effect of Alfentanil may be increased or last longer.
Pregnancy
You should not be given Alfentanil if you are pregnant or think you might be pregnant unless you have discussed this with your prescriber and the benefits of treatment are considered to outweigh the potential harm to the baby.
If you receive Alfentanil during pregnancy, your baby may become dependent and experience withdrawal symptoms after the birth which may need to be treated.
Alfentanil should not be used during childbirth as it can affect the baby’s breathing.
Breast-feeding
You should not be given Alfentanil while you are breastfeeding as it passes into breast milk and will affect your baby.
After you have been given Alfentanil you must not drive or operate machinery for at least 24 hours.
The medicine can affect your ability to drive as it may make you sleepy or dizzy.
Talk to your doctor or pharmacist if you are not sure whether it is safe for you to drive while receiving this medicine.
This medicine contains less than 1 mmol sodium (23 mg) per each 5 mg dose, that is to say essentially ‘sodium-free’.
Alfentanil will be given to you by specifically trained health care professionals and emergency equipment will be available.
Alfentanil is given as an injection into a vein, usually on the back of the hand or in the forearm.
Your prescriber should have discussed with you, how long the course of Alfentanil will last. They will arrange a plan for stopping treatment. This will outline how to gradually reduce the dose and stop receiving the medicine.
The amount of Alfentanil you need depends on your age, bodyweight, fitness, your condition, the use of other drugs and the type of surgery and level of anaesthesia that is needed.
It is unlikely that you will be given too much Alfentanil. This will be monitored during your operation / while you are in intensive care.
Do not suddenly stop receiving this medicine. If you want to stop receiving this medicine, discuss this with your prescriber first. They will tell you how to do this, usually by reducing the dose gradually so that any unpleasant withdrawal effects are kept to a minimum. Withdrawal symptoms such as restlessness, difficulty sleeping, irritability, agitation, anxiety, feeling your heartbeat (palpitations), increased blood pressure, feeling or being sick, diarrhoea, shaking, shivering or sweating may occur if you suddenly stop receiving this medicine.
Like all medicines, Alfentanil can cause side effects, although not everybody gets them. Your doctor will monitor these effects during your operation / while you are in intensive care.
Occasionally, Alfentanil may cause allergic reactions such as rash, itching, difficulty of breathing or swelling of the face, lips, throat or tongue. Please inform your doctor or nurse immediately if one or more of these reactions occur.
Very common (affects more than 1 in 10 people)
Common (affects fewer than 1 in 10 people)
Uncommon (affects fewer than 1 in 100 people)
Rare (affects fewer than 1 in 1,000 people)
Not known:
Drug Withdrawal
When you stop receiving Alfentanil, you may experience drug withdrawal symptoms, which include restlessness, difficulty sleeping, irritability, agitation, anxiety, feeling your heartbeat (palpitations), increased blood pressure, feeling or being sick, diarrhoea, shaking, shivering or sweating.
If you notice any of the following signs whilst receiving Alfentanil, it could be a sign that you have become addicted.
If you notice any of these signs, it is important you talk to your prescriber.
If you get any side effects, talk to your doctor, pharmacist or nurse: This includes any possible side effects not listed in this leaflet. You can also report side effects directly via the Yellow Card Scheme - Website: www. mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store. By reporting side effects you can help provide more information on the safety of this medicine.
Keep out of the sight and reach of children. Your doctor and pharmacist are responsible for the correct storage, use and disposal of Alfentanil.
Do not use Alfentanil after the expiry date which is stated on the carton and label after “EXP.”. The expiry date refers to the last day of that month.
Do not use Alfentanil if you notice the solution is not clear, colourless and free of particles or if the container is damaged.
The active substance is alfentanil hydrochloride.
1 ml of Alfentanil contains 5.44 mg alfentanil hydrochloride hydrate, equivalent to 5 mg alfentanil base.
The other ingredients are: water for injections, sodium chloride and hydrochloric acid
Alfentanil is a clear and colourless solution for injection.
Pack containing 5 or 10 clear glass ampoules of 1 ml.
Not all pack sizes may be marketed.
For any information about this medicine, please contact the Marketing Authorisation Holder
This leaflet was last revised in March 2026.
63490/14/26
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