Abstral Side Effects Center

Last updated on RxList: 5/21/2021
Abstral Side Effects Center

What Is Abstral?

Abstral (fentanyl) sublingual is a narcotic analgesic (pain reliever) used to treat severe pain in cancer patients who are already receiving and who are tolerant to opioid therapy for their underlying persistent cancer pain.

What Are Side Effects of Abstral?

Common side effects of Abstral include nausea, vomiting, drowsiness, dizziness, confusion, constipation, dry mouth, headache, tired feeling, or white patches or sores inside your mouth or on your lips.

Dosage for Abstral

The recommended dosage of Abstral tablets for adults is 1 tablet (100 mcg) sublingually (placed under the tongue) for each pain episode. Your doctor may adjust your dose as needed. Abstral adds to the effects of alcohol and other CNS depressants.

What Drugs, Substances, or Supplements Interact with Abstral?

Discuss with your doctor all medications and supplements you are taking because Abstral interacts with several other drugs. Abstral increases the risk of respiratory depression, medication errors, and potential abuse.

Abstral During Pregnancy or Breastfeeding

Abstral use in pregnant women has not been adequately studied. Fentanyl is excreted in human milk; do not use Abstral if you are breastfeeding. Withdrawal symptoms may occur if you suddenly stop using Abstral.

Additional Information

Our Abstral (fentanyl) sublingual Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


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Abstral Consumer Information

Get emergency medical help if you have signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Opioid medicine can slow or stop your breathing, and death may occur. A person caring for you should seek emergency medical attention if you have slow breathing with long pauses, blue colored lips, or if you are hard to wake up.

Call your doctor at once if you have:

  • slow heart rate, sighing, shallow breathing, breathing that stops during sleep;
  • severe drowsiness, feeling like you might pass out;
  • confusion, extreme fear, unusual thoughts or behavior; or
  • low cortisol levels--nausea, vomiting, loss of appetite, dizziness, worsening tiredness or weakness.

Seek medical attention right away if you have symptoms of serotonin syndrome, such as: agitation, hallucinations, fever, sweating, shivering, fast heart rate, muscle stiffness, twitching, loss of coordination, nausea, vomiting, or diarrhea.

Serious side effects may be more likely in older adults and those who are malnourished or debilitated.

Long-term use of opioid medication may affect fertility (ability to have children) in men or women. It is not known whether opioid effects on fertility are permanent.

Common side effects may include:

  • headache, dizziness, drowsiness, pale skin, feeling weak or tired;
  • constipation, nausea, vomiting; or
  • swelling in your hands or feet.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Read the entire detailed patient monograph for Abstral (Fentanyl Sublingual Tablets)

Abstral Professional Information


Clinical Studies Experience

Because clinical trials are conducted under widely varying conditions, adverse event rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

The safety of ABSTRAL has been evaluated in 311 opioid-tolerant cancer patients with breakthrough pain. Two hundred and seventy (270) of these patients were treated in multiple-dose studies. The duration of therapy for patients in multiple-dose studies ranged from 1-405 days with an average duration of 131 days and with 44 patients treated for at least 12 months.

The most commonly observed adverse reactions with ABSTRAL include typical opioid adverse reactions, such as nausea, constipation, somnolence and headache. Expect opioid side effects and manage them accordingly.

The clinical trials of ABSTRAL were designed to evaluate safety and efficacy in treating patients with cancer and breakthrough pain; all patients were taking concomitant opioids, such as sustained-release morphine, sustained-release oxycodone or transdermal fentanyl, for their persistent pain.

The adverse reaction data presented in Table 2 reflect the actual percentage of patients experiencing reactions among patients who received ABSTRAL for breakthrough pain along with concomitant opioid use for persistent pain. There has been no attempt to correct for concomitant use of other opioids, duration of ABSTRAL therapy or cancer-related symptoms.

Table 2 lists adverse reactions with an overall frequency of 5% or greater within the total population that occurred during titration by maximum dose received. The ability to assign ABSTRAL a dose-response relationship to these adverse reactions is limited by the titration schemes used in these studies.

Table2: Adverse Reactions Which Occurred During Titration at a Frequency of ≥ 5%

System Organ Class
Preferred term N (%)
100 mcg
200 mcg
300 mcg
400 mcg
600 mcg
800 mcg
Gastrointestinal disorders
Nausea 1 (4.5) 4 (17.4) 5 (9.1) 1 (2.6) 2 (3.8) 2 (2.5) 15 (5.6)
Nervous system disorders
Somnolence 0 2 (8.7) 4 (7.3) 2 (5.3) 2 (3.8) 2 (2.5) 12 (4.4)
Dizziness 0 0 3 (5.5) 2 (5.3) 0 1 (1.3) 6 (2.2)
Headache 0 0 0 1 (2.6) 3 (5.8) 1 (1.3) 5 (1.9)

Table 3 lists, by successful dose, adverse reactions with an overall frequency of ≥ 5% within the total population that occurred after a successful dose had been determined.

Table3: Adverse Reactions Which Occurred During Maintenance Therapy at a Frequency of ≥ 5%

System Organ Class
Preferred term N (%)
100 mcg
200 mcg
300 mcg
400 mcg
600 mcg
800 mcg
Gastrointestinal disorders
Nausea 1 (14.3) 0 2 (9.1) 0 1 (2.9) 6 (8.3) 10 (6.0)
Stomatitis 0 1 (8.3) 1 (4.5) 0 0 1 (1.4) 3 (1.8)
Constipation 0 0 1 (4.5) 2 (10.0) 1 (2.9) 4 (5.6) 8 (4.8)
Dry mouth 0 0 0 1 (5.0) 2 (5.7) 0 3 (1.8)
Nervous system disorders
Headache 0 0 0 2 (10.0) 1 (2.9) 2 (2.8) 5 (3.0)
Dysgeusia 1 (14.3) 0 0 0 0 1 (1.4) 2 (1.2)
General disorders and administration site conditions
Fatigue 0 0 0 1 (5.0) 2 (5.7) 0 3 (1.8)
Injury, poisoning and procedural complications
Accidental overdose 1 (14.3) 0 0 0 0 0 1 (0.6)
Respiratory, thoracic and mediastinal disorders
Dyspnoea 0 1 (8.3) 0 0 0 0 1 (0.6)
Skin and subcutaneous disorders
Hyperhidrosis 1 (14.3) 0 0 0 0 1 (1.4) 2 (1.2)

The frequencies listed below represent adverse reactions that occurred in ≥ 1% of patients from two clinical trials who experienced that reaction while receiving ABSTRAL. Reactions are classified by system organ class.

Adverse Reactions ( ≥ 1%)

Cardiac disorders: bradycardia, tachycardia.

Eye disorders: vision blurred.

Gastrointestinal disorders: abdominal pain, abdominal pain upper, aphthous stomatitis, constipation, dry mouth, dyspepsia, gingival ulceration, impaired gastric emptying, lip ulceration, mouth ulceration, nausea, stomach discomfort, stomatitis, tongue disorder, vomiting.

General disorders and administration site conditions: asthenia, drug withdrawal syndrome, fatigue, malaise.

Immune system disorders: drug hypersensitivity.

Injury, poisoning and procedural complications: accidental overdose.

Metabolism and nutrition disorders: anorexia, decreased appetite.

Nervous system disorders: amnesia, disturbance in attention, dizziness, dysgeusia, headache, hypoesthesia, lethargy, parosmia, somnolence, tremor.

Psychiatric disorders: affect lability, anxiety, confusional state, depression, disorientation, dysphoria, euphoric mood, insomnia, mental status changes, paranoia, sleep disorder.

Reproductive system and breast disorders: erectile dysfunction.

Respiratory, thoracic and mediastinal disorder: dyspnea, oropharyngeal pain, throat tightness.

Skin and subcutaneous disorders: hyperhidrosis, night sweats, pruritus, rash, skin lesion.

Vascular disorders: hypotension.

Read the entire FDA prescribing information for Abstral (Fentanyl Sublingual Tablets)

© Abstral Patient Information is supplied by Cerner Multum, Inc. and Abstral Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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