Prilosec and Fastin drug interactions - a phase IV clinical study of FDA data

Summary:

Drug interactions are reported among people who take Prilosec (omeprazole) and Fastin (phentermine hydrochloride). Common drug interactions include ventricular hypertrophy among females and arrhythmia among males.

The phase IV clinical study analyzes what interactions people have when they take Prilosec and Fastin. It is created by eHealthMe based on reports of 51 people who take the same drugs from the FDA, and is updated regularly.

What is Prilosec?

Prilosec has active ingredients of omeprazole. It is often used in gastroesophageal reflux disease. eHealthMe is studying from 175,286 Prilosec users. Check the latest studies of Prilosec.

What is Fastin?

Fastin has active ingredients of phentermine hydrochloride. It is often used in weight loss. eHealthMe is studying from 2,168 Fastin users. Check the latest studies of Fastin.

On Aug, 01, 2026

51 people who take Prilosec and Fastin together, and have interactions are studied.

What are the common drug interactions of Prilosec and Fastin, by gender? *:

female:

Ventricular hypertrophy (enlargement of ventricles (lower chambers) in the heart)
Abdominal tenderness
Adult respiratory distress syndrome (type of lung (pulmonary) failure)
Aggression
Anaemia (lack of blood)
Aortic artery blockage
Aortic valve incompetence
Aphasia (damage to the parts of the brain that control language)
Arthralgia (joint pain)
Asthenia (weakness)

male:

Arrhythmia (irregular heartbeat)
Angioedema (rapid swelling of the dermis)
Hypoxia (low oxygen in tissues)
Intraventricular haemorrhage (intraventricular bleeding)
Kawasaki's disease (an autoimmune disease in which the medium-sized blood vessels throughout the body become inflamed)
Lethargy (tiredness)
Pneumonia
Pneumonia viral
Pulmonary artery stenosis congenital (congenital -narrowing (stenosis) that occurs in the lung artery)
Pulmonary hypertension (increase in blood pressure in the lung artery)

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

0-1:

n/a

2-9:

n/a

10-19:

n/a

20-29:

Chest discomfort
Dyspnoea (difficult or laboured respiration)
Flatulence (flatus expelled through the anus)
Generalised oedema (swelling all over the body)
Pain
Presyncope
Pulmonary hypertension (increase in blood pressure in the lung artery)
Therapeutic response unexpected with drug substitution

30-39:

Anxiety
Pain
Anhedonia (inability to experience pleasure from activities usually found enjoyable)
Blood cholesterol increased
Cardiovascular disorder (heart diseases)
Chest pain
Cholecystitis infective (infection of gallbladder capable to infect other organs)
Cholelithiasis (the presence or formation of gallstones in the gallbladder or bile ducts)
Depression
Dizziness

40-49:

Vomiting
Chest pain
Dyspnoea (difficult or laboured respiration)
Cardiovascular disorder (heart diseases)
Pulmonary hypertension (increase in blood pressure in the lung artery)
Cardiac murmur (an heart sound in valve abnormality)
Valvular heart disease (diseases of the heart valves)
Anxiety
Cardiomegaly (increased size of heart than normal)
Chronic obstructive airways disease

50-59:

Chronic kidney disease
Cardiac murmur (an heart sound in valve abnormality)
Dyspnoea (difficult or laboured respiration)
Palpitations (feelings or sensations that your heart is pounding or racing)
Tachycardia (a heart rate that exceeds the range of 100 beats/min)
Tricuspid valve incompetence (inefficient heart valve)
Renal failure (kidney dysfunction)
Activated partial thromboplastin time prolonged
Adult respiratory distress syndrome (type of lung (pulmonary) failure)
Anaemia (lack of blood)

60+:

Renal failure (kidney dysfunction)
Renal injury (kidney injury)
Cardiac murmur (an heart sound in valve abnormality)
Chronic kidney disease
Dyspnoea (difficult or laboured respiration)
Valvular heart disease (diseases of the heart valves)
Blood pressure increased
Chest pressure sensation (feeling of pressure on chest)
Hypertension (high blood pressure)
Sensation of pressure

What are the existing conditions these people have? *

Pain: 9 people, 17.65%
Stress And Anxiety: 7 people, 13.73%
Nausea (feeling of having an urge to vomit): 7 people, 13.73%
Headache (pain in head): 7 people, 13.73%
Fever: 7 people, 13.73%
Diabetes: 7 people, 13.73%
Nasopharyngitis (inflammation of the nasopharynx): 6 people, 11.76%
Blood Pressure Abnormal: 6 people, 11.76%
The Flu (the flu is caused by an influenza virus): 5 people, 9.80%
Gastric Disorder (disease of stomach): 5 people, 9.80%

* Approximation only. Some reports may have incomplete information.

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