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Syndros Side Effects

Generic Name: dronabinol

Note: This page contains side effects data for the generic drug dronabinol. It is possible that some of the dosage forms included below may not apply to the brand name Syndros.

For the Consumer

Applies to dronabinol: oral capsule, oral capsule liquid filled, oral solution

As well as its needed effects, dronabinol (the active ingredient contained in Syndros) may cause unwanted side effects that require medical attention.

Major Side Effects

If any of the following side effects occur while taking dronabinol, check with your doctor immediately:

Less common
  • Changes in mood
  • confusion
  • delusions
  • fast or pounding heartbeat
  • feelings of unreality
  • loss of memory
  • mental depression
  • nervousness or anxiety
  • problems with memory
  • seeing, hearing, or feeling things that are not there
  • Blurred vision
  • chills
  • dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
  • sweating
  • unusual tiredness or weakness
Incidence not known:
  • Fainting
  • feeling of warmth
  • hives or rash
  • redness of the face, neck, arms, and occasionally, upper chest
  • seizures
  • sores in the mouth
  • swelling of the lips
  • tightness in the throat
  • trouble sleeping

If any of the following symptoms of overdose occur while taking dronabinol, get emergency help immediately:

Symptoms of overdose:
  • Being forgetful
  • change in how fast you think time is passing
  • change in your sense of smell, taste, sight, sound, or touch
  • constipation
  • decrease in motor coordination
  • drowsiness (severe)
  • dryness of the mouth (severe)
  • false sense of well-being
  • feeling sluggish
  • panic reaction
  • problems in urinating
  • redness of the eyes
  • seizures
  • slurred speech
  • unusual drowsiness or dullness

Minor Side Effects

Some dronabinol side effects may not need any medical attention. As your body gets used to the medicine these side effects may disappear. Your health care professional may be able to help you prevent or reduce these side effects, but do check with them if any of the following side effects continue, or if you are concerned about them:

More common:
  • Clumsiness or unsteadiness
  • dizziness
  • drowsiness
  • false sense of well-being
  • nausea
  • trouble with thinking
  • vomiting
Less common or rare:
  • Abdominal or stomach pain
  • flushing of the face
  • lack or loss of strength
  • restlessness
  • Burning, dry, or itching eyes
  • continuing ringing or buzzing or other unexplained noise in the ears
  • cough
  • diarrhea
  • discharge, excessive tearing
  • headache
  • hearing loss
  • redness, pain, swelling of the eye, eyelid, or inner lining of the eyelid
  • runny nose
  • sneezing
  • stuffy nose

For Healthcare Professionals

Applies to dronabinol: oral capsule


Very common (10% or more): Feeling high/easy laughing, elation, heightened awareness (up to 24%)
Common (1% to 10%): Euphoria, paranoid reaction, abnormal thinking
Frequency not reported: Anxiety/nervousness, confusion, depersonalization, hallucinations, depression, nightmares[Ref]

Nervous system

Common (1% to 10%): Dizziness, somnolence
Frequency not reported: Amnesia, ataxia, speech difficulties, tinnitus, headache, syncope
Postmarketing reports: Seizure/seizure-like activity, fatigue[Ref]


Uncommon (0.1% to 1%): Hypotension, flushing
Frequency not reported: Palpitations, tachycardia, vasodilation/facial flush[Ref]


Common (1% to 10%): Abdominal pain, nausea, vomiting
Uncommon (0.1% to 1%): Diarrhea
Frequency not reported: Fecal incontinence[Ref]


Uncommon (0.1% to 1%): Conjunctivitis
Frequency not reported: Vision difficulties[Ref]


Frequency not reported: Asthenia, chills, malaise
Postmarketing reports: Fatigue[Ref]


Frequency not reported: Myalgia[Ref]


Frequency not reported: Hepatic enzyme elevation[Ref]


Frequency not reported: Anorexia[Ref]


Frequency not reported: Cough, rhinitis, sinusitis[Ref]


Frequency not reported: Sweating[Ref]


1. "Product Information. Marinol (dronabinol)." Roxane Laboratories Inc, Columbus, OH.

It is possible that some side effects of Syndros may not have been reported. These can be reported to the FDA here. Always consult a healthcare professional for medical advice.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.