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Side Effects of Alfentanil (Alfenta)



Alfentanil, which is sold under the brand name Alfenta, belongs to a group of medicines called opioid analgesics – medications that relieve or prevent pain. Alfentanil is a strong painkiller which has a very rapid effect. The medication is used for anesthesia in surgery.

Serious Side Effects of Alfentanil

The most serious adverse effects of alfentanil according to the Alfentanil label as reported by the FDA include:

  • Respiratory depression
  • Hypotensive effect
  • Increased intracranial pressure
  • Gastrointestinal effects

Common Side Effects of Alfentanil

The following side effects have been reported with the use of alfentanil according to the Alfentanil label as reported by the FDA:

  • Very Common: nausea
  • Common: headache, low blood pressure (hypotension), pruritus (itching), pain at injection site, shallow breathing (respiratory depression/hypoxemia), dizziness, sleepiness, drowsiness, vomiting

Less Common Side Effects

Uncommon side effects, according to the Alfentanil label, include: excitation, high blood pressure (hypertension), coughing, rigid muscles, rapid heartbeat (tachycardia), slow heartbeat (bradycardia), asthma-like symptoms (e.g. breathing difficulties, spasm of the airway), shivering/feeling cold, unable to urinate (urinary retention), visual disturbances.

Understand Your Risks with the Rxight® Genetic Test

Rxight® pharmacogenetic testing is designed to evaluate your unique reactions to alfentanil and other opioids and thus help avoid these adverse, potentially life-threatening side effects and allergic reactions. All that is required is a simple cheeks swab of your DNA, after which your sample will be sent to our lab for processing. The panel contains over 200 different prescription medications and over-the-counter products across 50 clinically significant medication classes. Rxight® is the most comprehensive CLIA-certified PGx testing service available.

How Does Pharmacogenetic Testing Work?

Many people have normal activity of liver enzymes responsible for processing alfentanil, and thus experience therapeutic value with minimal side effects on standard doses. However, some people may have differences in one or more of these liver enzymes, leading to dangerously high levels – which can lead to serious adverse reactions – or inadequate levels of alfentanil, which causes it to be ineffective. There are 18 key genes involved in medication metabolism, and their variants (alleles) are analyzed to determine which variant you have – in a process called “SNP genotyping.” Armed with the results of PGx testing, your prescriber can adjust your dose based on your genetically modulated liver enzyme activity targeting a particular drug or drug class – preferably before treatment begins.

Contributors to this Article:
Michael Sapko, MD, PhD; Deborah Kallick, PhD, Medicinal Chemistry

Read more about Rxight® pharmacogenetic testing