Alfentanil is an opioid analgesic drug used as an anesthetic during surgical procedures. When used recreationally, it can cause addiction and fatal overdose.

Alfentanil (Alfenta) is a fast-acting opioid pain medication that has roughly one-tenth the potency of fentanyl. Alfentanil’s maximum respiratory depressant and analgesic effects can take effect within one to two minutes of administration. This medication has a high potential for addiction, so only use this medication under the care of a medical professional.

What Is Alfentanil?

Alfentanil (Alfenta) is a powerful opioid medication used to treat severe pain. Alfenta is derived from the medicine fentanyl and works by activating opioid receptors in the brain, suppressing nerves that transmit pain signals to the brain.

Alfentanil is intended to be administered intravenously to patients undergoing procedures to help control pain and keep patients asleep during surgery. It can also be used as a pain medication in critically ill people.

The powerful narcotic is only supposed to be used in carefully-monitored settings and administered by a medical professional because it can cause fatal respiratory depression. In the United States, it must be prescribed by a doctor.

What Makes Alfentanil Addictive?

Alfentanil activates opioid receptors in the brain. While this does suppress pain, it also releases chemicals in the brain called endorphins. These chemicals cause our ability to sense pleasure, and using alfentanil artificially creates a temporary pleasurable feeling. Because alfentanil works so quickly and intensely, this medicine can be highly addictive.

Because alfentanil has a high potential for addiction and an intense effect, it is only administered in a hospital environment. Misusing the drug can easily cause respiratory arrest, killing the user if medical personnel is not present, and monitoring its use.

Because the medication has to be used in a clinical or hospital setting, it may be harder to obtain than other opioids. Medical diversion can still occur, making the drug available on the streets. When the drug is taken outside of a hospital setting, it has a substantially higher overdose rate.

Signs, Symptoms and Side Effects

Respiratory depression is the primary side effect of Alfentanil use. Pinpoint pupils, decreased level of consciousness and slow or absent breathing are the primary signs of an overdose. Snoring or gasping breathing may also indicate an overdose.

Short-Term Side Effects and Long-Term Consequences

Common side effects of alfentanil include:

  • Decreased rate of breathing
  • Changes in heart rate
  • Confusion
  • Constipation
  • Dry mouth
  • Fainting
  • Hallucinations
  • Headaches
  • Nausea and vomiting
  • Constricted pupils
  • Problems walking
  • Slurred speech
  • Weakness

Long-term abuse can lead to physical and mental side effects like:

  • A weakened immune system
  • Bowel obstruction and rupture
  • Chronic infections
  • Paranoia, delusions, and changes in personality
  • Physical and psychological addiction and dependence
  • Problems breathing

There are lifestyle effects of opioid addiction, too. Damaged relationships and problems at home, school or work can all stem from ongoing drug misuse and addiction. People who struggle with addiction may have legal and financial trouble, and their drug use usually ends up affecting every area of their life and the people around them.

Alfentanil Withdrawal

When someone is substance-dependent, they will experience withdrawal symptoms if they quit cold turkey or even lower their dose. Opioid withdrawal isn’t usually life-threatening, but it is an obstacle to overcoming the addiction because it’s uncomfortable. Cravings can be severe as well, which may result in a relapse.

Withdrawal Symptoms

Common withdrawal symptoms include:

  • Anxiety
  • Diarrhea
  • Elevated heart rate
  • Hypertension
  • Muscle and bone aches and pains
  • Nausea and vomiting
  • Restlessness and irritability
  • Sweating and/or chills
  • Teary eyes
  • Fever
  • Yawning, insomnia, and sleep disturbances
  • Cravings

Withdrawal Timeline and Symptom Duration

Withdrawal symptoms could begin around 8 hours after the last dose was taken. Withdrawal symptoms will usually peak within the first few days after the last dose was used, and they will start to subside within the first week.

For some people, especially those that have taken opioids for a long time or used them heavily, symptoms can continue for weeks or months. Extended withdrawal symptoms are often psychological, such as depression, anxiety, problems experiencing pleasure and cravings for the drug.

Managing the Symptoms of Withdrawal

Some options for managing alfentanil withdrawal symptoms can include medications, an outpatient detox program supervised by a medical professional, or a medical detox program in a professional setting.

A physician will often instruct patients to follow a tapering-down schedule as opposed to stopping cold turkey. Tapering is also called weaning off a drug, and it can help prevent some of the more severe withdrawal symptoms.

Alfentanil Treatment & Detox

When someone is addicted to alfentanil, they will find it difficult to stop using the drug, even when they can tell that using it is having a negative effect on their lives. A professional rehab program is recommended for people who struggle with addiction. The treatment options can include medication-assisted treatment, detox, and inpatient or outpatient rehab.

Alfentanil Detox

Detox involves your body removing the drug from your system. In medical detox, medical care is provided by a team of professionals round-the-clock as someone goes through the withdrawal process. When a medical detox is the first step in a treatment program, it improves the chances of successfully completing addiction treatment.

Medications can be given during detox to help reduce the severity and duration of withdrawal symptoms. The medications that can be used during detox vary based on your specific addiction and situation, making supervision by medical professionals necessary.

Alfentanil Rehab

Opioid addiction can be particularly challenging to treat because of how powerful these drugs are, so it’s important to look for a program specializing in treating opioid addiction and dependence. An opioid rehabilitation program should aim to help participants stop using the drug and provide them with counseling and guidance to maintain their recovery long-term. A qualified rehab program should also help participants return to their lives, responsibilities and loved ones in a productive way.

Inpatient Rehab

During inpatient rehab, participants live onsite in a residential facility. The benefits of this kind of setting include constant support, supervision and structure. Detox will be the initial focus of rehab, followed by professional support in learning how to avoid relapse. Inpatient rehab allows for 24-hour monitoring and support as you overcome addiction.

Outpatient Rehab

An outpatient program can vary quite a bit in treatment structure and approach. Some programs consist of one-on-one counseling or group therapy that might happen once or twice a week. There are also more intensive programs, which may include living in a sober living facility. These can provide more freedom and autonomy compared to an inpatient program. Outpatient programming may also follow a residential inpatient program as a step-down approach that eases the patient into daily life.

Choosing a Rehab Center

Choosing a rehab center is an important decision if you or your loved ones are struggling with addiction. There are logistical considerations to keep in mind. Some of the factors to think about when choosing a rehab center include:

  • What is the severity of the addiction?
  • Have other treatments been tried previously?
  • How long has the person been misusing alfentanil and are multiple substances being misused simultaneously?
  • Does the person have a strong home support system?
  • Would the person potentially benefit from being away from their current environment?
  • Does the person have a co-occurring mental health disorder (dual diagnosis)?

If you or a loved one is struggling with an alfentanil addiction, The Recovery Village has an experienced medical team ready to help you on the road to lifelong recovery. Contact us today to discuss treatment options that can meet your needs.

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Editor – Melissa Carmona
Melissa Carmona puts years of writing and editing experience to work helping people understand substance abuse, addiction and mental health disorders. Read more
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Medically Reviewed By – Benjamin Caleb Williams, RN
Benjamin Caleb Williams is a board-certified Emergency Nurse with several years of clinical experience, including supervisory roles within the ICU and ER settings. Read more


How long does alfentanil stay in your system?

Alfentanil will have an effect for about an hour or less in most people, although the exact length of time varies based on gender, age, weight, overall health and other factors. Alfentanil may remain detectable in urine for up to three days or more. As with most substances, it may remain at testable levels in hair follicles for up to 90 days following administration.

Is it safe for a loved one to drink if prescribed alfentanil for pain?

No, alfentanil should not be mixed with alcohol. Doing so can lead to many negative side effects and could even be fatal.

Be honest with your doctor about your alcohol habits and whether you feel that you can abstain from using alcohol while taking alfentanil. If you feel that you cannot avoid alcohol while receiving this medication, discuss other options with your doctor.

In case of an emergency, will administering naloxone be effective in the event of an overdose?

Yes. In the event of alfentanil overdose, standard opioid overdose protocol should be followed. The primary concerns are calling 911 while supporting the individual’s respiration, ensuring adequate ventilation and administering naloxone. When administered intranasally or intravenously, naloxone can completely negate the effects of alfentanil within seconds. It is important to keep in mind that naloxone will wear off before the effects of an overdose. Multiple doses may need to be given while waiting for EMS to arrive.

Is it safe to take alfentanil while pregnant? What if a loved one or I am dependent?

No, it’s not typically safe to take any opioid drug during pregnancy. However, if a loved one is dependent upon opioids and becomes pregnant, she should not suddenly stop since this could result in further complications.

If use suddenly stops during pregnancy, placental abruption may occur. This can cause serious bleeding and could potentially be fatal. Stopping suddenly or “cold turkey” can also cause a miscarriage.

Neonatal abstinence syndrome (NAS) refers to a condition in which a baby is exposed to opioids like alfentanil while in the womb. As a result, the baby is born withdrawing from opioids.

Women who are using opioids may be less likely to receive the prenatal care they need, and they may have nutritional deficits. There are increased risks for infections such as HIV, and there can be dangers related to drug-seeking, such as violence or criminal issues.

If you’re using opioids like alfentanil and become pregnant, the best option is to talk with your healthcare provider honestly. It is possible to detox from opiates while pregnant.

Medical Disclaimer

The Recovery Village aims to improve the quality of life for people struggling with substance use or mental health disorder with fact-based content about the nature of behavioral health conditions, treatment options and their related outcomes. We publish material that is researched, cited, edited and reviewed by licensed medical professionals. The information we provide is not intended to be a substitute for professional medical advice, diagnosis or treatment. It should not be used in place of the advice of your physician or other qualified healthcare providers.