Medical Editor: John P. Cunha, DO, FACOEP
Subsys (fentanyl) sublingual spray is a potent opioid analgesic (pain reliever) indicated for the treatment of breakthrough cancer pain (BTCP) in opioid-tolerant adult patients who are already routinely taking other opioid pain medicines around-the-clock for cancer pain. Common side effects of Subsys include:
- shortness of breath,
- loss of appetite,
- weakness, and
Subsys can cause serious side effects, including:
- breathing problems that can become life-threatening,
- low blood pressure,
- as well as the potential for abuse or addiction.
Subsys is a liquid medicine that is sprayed underneath your tongue (sublingual) and allowed to absorb. Subsys is dosed as one to two sprays given underneath the tongue. Subsys may interact with drugs that may cause sleepiness (such as other pain medicines), anti-depressants, sleeping pills, anti-anxiety medicines, antihistamines, and muscle relaxants or tranquilizers. Patients should not drink alcohol while taking Subsys. Tell your doctor all medications and supplements you use. Subsys may cause serious harm to unborn babies. Subsys can also pass into breast milk and cause serious harm to babies. Patients should not use Subsys while breastfeeding. Withdrawal symptoms may occur if you suddenly stop taking Subsys.
Our Subsys 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.
The following serious adverse reactions are described, or described in greater detail, in other sections:
- Life-Threatening Respiratory Depression [see WARNINGS AND PRECAUTIONS]
- Interactions with Benzodiazepines and other CNS Depressants [see WARNINGS AND PRECAUTIONS]
- Addiction, Abuse, and Misuse [see WARNINGS AND PRECAUTIONS]
- Neonatal Opioid Withdrawal Syndrome [see WARNINGS AND PRECAUTIONS]
- Serotonin Syndrome [see WARNINGS AND PRECAUTIONS]
- Adrenal Insufficiency [see WARNINGS AND PRECAUTIONS]
- Severe Hypotension [see WARNINGS AND PRECAUTIONS]
- Gastrointestinal Adverse Reactions [see WARNINGS AND PRECAUTIONS]
- Seizures [see WARNINGS AND PRECAUTIONS]
Clinical Trials Experience
Because clinical trials are conducted under widely varying conditions, adverse reaction 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 SUBSYS has been evaluated in a total of 359 opioid-tolerant patients with breakthrough cancer pain. The duration of SUBSYS use varied during the open-label study. Safety data from a longterm extension study showed that the average duration of therapy in the open-label study was 66 days. The maximum duration of therapy was 149 days. The dose range studied in these trials ranged from 100 mcg per dose to 1600 mcg per dose.
The most serious adverse reactions associated with all opioids including SUBSYS are respiratory depression (potentially leading to apnea or respiratory arrest), circulatory depression, hypotension, and shock. Follow all patients for symptoms of respiratory depression.
The most common adverse reaction leading to discontinuation of SUBSYS was nausea. There were also adverse reactions of abdominal distension, anorexia, confusional state, disorientation, somnolence, and constipation.
The clinical trials of SUBSYS were designed to evaluate safety and efficacy in treating breakthrough cancer pain; all patients were also taking concomitant opioids, such as sustained-release morphine or transdermal fentanyl, for their persistent cancer pain. The adverse event data presented here reflect the actual percentage of patients experiencing each adverse effect among patients who received SUBSYS for breakthrough cancer pain along with a concomitant opioid for persistent cancer pain.
Table 4 lists adverse reactions with an overall frequency of 5% or greater that occurred during titration in the clinical trials. Adverse reactions are listed in descending order of frequency within each system organ class.
Table 4: Percent of Patients with Specific Adverse
Events During Titration in the Clinical Trials (Events in 5% or More of
|System Organ Class||Titration
|Nervous System Disorders|
The following adverse reactions occurred during titration in the clinical trials with an overall frequency of 1% or greater and are listed in descending order of frequency within each system organ class.
Cardiac Disorders: Tachycardia
Gastrointestinal Disorders: Diarrhea, stomatitis, dry mouth
General Disorders and Administration Site Conditions: Application site irritation, pyrexia, edema peripheral, fatigue, asthenia
Metabolism and Nutrition Disorders: Decreased appetite
Psychiatric Disorders: Depression, confusional state, hallucination, insomnia
Respiratory, Thoracic and Mediastinal Disorders: Dyspnea
Skin and Subcutaneous Tissue Disorders: Pruritus
The following reactions occurred during titration in the clinical trials with an overall frequency of less than 1% and are listed in descending order of frequency within each system organ class.
Eye Disorders: Vision blurred, dry eye
Gastrointestinal Disorders: Abdominal pain
Injury, Poisoning and Procedural Complications: Fall
Metabolism and Nutrition Disorders: Dehydration, anorexia
Psychiatric Disorders: Anxiety, agitation
Renal and Urinary Disorders: Urinary retention
Respiratory, Thoracic and Mediastinal Disorders: Cough, increased bronchial secretion, dysphonia, pharyngolaryngeal pain
Skin and Subcutaneous Tissue Disorders: Hyperhidrosis
Vascular Disorders: Hot flush
Table 5 lists adverse reactions with an overall frequency of 5% or greater for the total safety database subsequent to titration during the clinical trials.
Table 5: Adverse Reactions Subsequent to Titration in
5% or More of Patients
|System Organ Class||Dosing
|General Disorders and Administration Site Conditions|
|Respiratory, Thoracic and Mediastinal Disorders|
The following adverse reactions occurred during the dosing period of the clinical trial with an overall frequency of 1% or greater and are listed in descending order of frequency within each system organ class.
Cardiac Disorders: Tachycardia, sinus tachycardia
General Disorders and Administration Site Conditions: Edema peripheral, fatigue, pyrexia, chest pain, drug withdrawal syndrome, chills, irritability, malaise, application site irritation
Injury, Poisoning and Procedural Complications: Contusion
Musculoskeletal and Connective Tissue Disorders: Back pain, arthralgia, muscular weakness
Nervous System Disorders: Hypoesthesia, lethargy, sedation, tremor, somnolence, headache, dizziness
Psychiatric Disorders: Depression, restlessness, agitation, confusional state, insomnia, hallucination, disorientation
Renal and Urinary Disorders: hypertension, hypotension
Skin and Subcutaneous Tissue Disorders: hyperhidrosis, pruritus
In a single-dose mucositis study, a group of patients with Grade 1 or 2 oral mucositis (n=9) and without oral mucositis (n=9) were included in a clinical trial designed to support the safety of SUBSYS. Two of the nine subjects with mucositis (one with Grade 1 and one with Grade 2) reported a burning sensation in the oral mucosa after treatment. Both of these events were considered mild and probably related to treatment. There was no change in grade of mucositis after treatment for any subject.
The following adverse reactions have been identified during post approval use of fentanyl. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
Serotonin syndrome: Cases of serotonin syndrome, a potentially life-threatening condition, have been reported during concomitant use of opioids with serotonergic drugs.
Adrenal insufficiency: Cases of adrenal insufficiency have been reported with opioid use, more often following greater than one month of use.
Anaphylaxis: Anaphylaxis has been reported with ingredients contained in SUBSYS.
Read the entire FDA prescribing information for Subsys (Fentanyl Sublingual Spray)