Cysteine and Fentanyl drug interactions - a phase IV clinical study of FDA data

Summary:

Drug interactions are reported among people who take Cysteine (n - acetyl cysteine) and Fentanyl (fentanyl citrate). Common drug interactions include decreased appetite among females and fall among males.

The phase IV clinical study analyzes what interactions people have when they take Cysteine and Fentanyl. It is created by eHealthMe based on reports of 15 people who take the same drugs from the FDA, and is updated regularly.

What is Cysteine?

Cysteine has active ingredients of n - acetyl cysteine. eHealthMe is studying from 1,755 Cysteine users. Check the latest studies of Cysteine.

What is Fentanyl?

Fentanyl has active ingredients of fentanyl citrate. It is often used in pain. eHealthMe is studying from 73,301 Fentanyl users. Check the latest studies of Fentanyl.

eHealthMe: drug outcomes in the real world

eHealthMe runs one of the largest post-marketing drug safety studies in the world. We study millions of patients and 5,000 more each day. Our data-driven phase IV clinical trials have been referenced on 800+ peer-reviewed medical publications including The Lancet, Mayo Clinic Proceedings, and Nature. Tools to study our phase IV findings are available to the public, anonymous and free >>>.

On Aug, 15, 2026

15 people who take Cysteine and Fentanyl together, and have interactions are studied.

Cysteine and Fentanyl drug interactions.

What are the common drug interactions of Cysteine and Fentanyl, by gender? *:

female:

Decreased appetite
Acute coronary syndrome (acute chest pain and other symptoms that happen because the heart does not get blood)
Acute respiratory failure
Bronchospasm (spasm of bronchial smooth muscle producing narrowing of the bronchi)
Cardiomyopathy (weakening of the heart muscle)
Chills (felling of cold)
Death
Depressed level of consciousness
Dizziness
Dyspnoea (difficult or laboured respiration)

male:

Fall
Pneumonia
Accident
Arrhythmia (irregular heartbeat)
Ascites (accumulation of fluid in the abdominal cavity)
Cardiac failure acute
Chronic obstructive pulmonary disease (a progressive disease that makes it hard to breathe)
Dental caries
Drug abuse
Encephalopathy (functioning of the brain is affected by some agent or condition)

What are the common drug interactions of Cysteine and Fentanyl, by age (0-1 to 60+)? *:

0-1:

n/a

2-9:

n/a

10-19:

n/a

20-29:

n/a

30-39:

n/a

40-49:

Arrhythmia (irregular heartbeat)
Cardiac failure acute
Injection site swelling

50-59:

Infection
Post concussion syndrome
Suicidal ideation
Ascites (accumulation of fluid in the abdominal cavity)
Decreased appetite
Drug abuse
Encephalopathy (functioning of the brain is affected by some agent or condition)
Fluid overload (too much fluid in the blood)
Haemorrhagic anaemia (anaemia due to excessive bleeding)
Hepatic failure (liver failure)

60+:

Neoplasm progression (growth of tumour)
Pneumonia
Depressed level of consciousness
Eosinophilia (eosinophil count in the peripheral blood exceeds)
Interstitial lung disease
Organising pneumonia (pathologically by the presence in the distal air spaces of buds of granulation tissue)

What are the existing conditions these people have? *

Cough: 2 people, 13.33%
Urine Output Decreased: 1 person, 6.67%
Hepatitis C: 1 person, 6.67%
Fluid Overload (too much fluid in the blood): 1 person, 6.67%
Fibromyalgia (a long-term condition which causes pain all over the body): 1 person, 6.67%
Depression: 1 person, 6.67%
Coronary Artery Insufficiency (insufficiency of artery to carry blood to heart): 1 person, 6.67%
Constipation: 1 person, 6.67%
Cardiac Failure Acute: 1 person, 6.67%
Cardiac Failure: 1 person, 6.67%

* Approximation only. Some reports may have incomplete information.

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