Phenytoin and Lopressor drug interactions - a phase IV clinical study of FDA data

Summary:

Drug interactions are reported among people who take Phenytoin (phenytoin) and Lopressor (metoprolol tartrate). Common drug interactions include encephalopathy among females and pleural effusion among males.

The phase IV clinical study analyzes what interactions people have when they take Phenytoin and Lopressor. It is created by eHealthMe based on reports of 69 people who take the same drugs from the FDA, and is updated regularly.

What is Phenytoin?

Phenytoin has active ingredients of phenytoin. It is often used in epilepsy. eHealthMe is studying from 15,753 Phenytoin users. Check the latest studies of Phenytoin.

What is Lopressor?

Lopressor has active ingredients of metoprolol tartrate. It is often used in high blood pressure. eHealthMe is studying from 33,152 Lopressor users. Check the latest studies of Lopressor.

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 Jul, 04, 2026

69 people who take Phenytoin and Lopressor together, and have interactions are studied.

Phenytoin and Lopressor drug interactions.

What are the common drug interactions of Phenytoin and Lopressor, by gender? *:

female:

Encephalopathy (functioning of the brain is affected by some agent or condition)
Oedema peripheral (superficial swelling)
Renal failure acute (rapid kidney dysfunction)
Vision blurred
Drug rash with eosinophilia and systemic symptoms (adverse drug reactions with rash)
Dry eye (lack of adequate tears)
Scar
Pain
Urinary tract infection
Convulsion (muscles contract and relax rapidly and repeatedly, resulting in an uncontrolled shaking of the body)

male:

Pleural effusion (water on the lungs)
Respiratory distress (difficulty in breathing)
Hypotension (abnormally low blood pressure)
Oedema (fluid collection in tissue)
Pneumonia
Pyrexia (fever)
Cholelithiasis (the presence or formation of gallstones in the gallbladder or bile ducts)
Hyperkalaemia (damage to or disease of the kidney)
Pulmonary congestion (congestion in the lungs)
Aeromona infection (infection caused by bacteria aeromona)

What are the common drug interactions of Phenytoin and Lopressor, 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:

Cellulitis (infection under the skin)
Aeromona infection (infection caused by bacteria aeromona)
Anaemia (lack of blood)
Arteriovenous fistula occlusion
Arteriovenous fistula thrombosis (formation of a blood clot inside a blood vessel-av fistula)
Asthenia (weakness)
Atelectasis (partial or complete collapse of the lung)
Azotaemia (excess of urea or other nitrogenous compounds in the blood)
Back pain
Bone disorder

50-59:

Hepatic failure (liver failure)
Impaired healing
Liver disorder (liver diseases)
Malaise (a feeling of general discomfort or uneasiness)
Malnutrition (a condition that results from eating a diet in which certain nutrients are lacking)
Metabolic acidosis (body produces too much acid, or when the kidneys are not removing enough acid from the body)
Multi-organ failure (multisystem organ failure)
Musculoskeletal discomfort (discomfort in the body's muscles, joints, tendons, ligaments and nerves)
Nasal congestion (blockage of the nasal passages usually due to membranes lining the nose becoming swollen from inflamed blood vessels)
Neuritis (inflammation of nerve)

60+:

Renal failure acute (rapid kidney dysfunction)
Drug rash with eosinophilia and systemic symptoms (adverse drug reactions with rash)
Coma (state of unconsciousness lasting more than six hours)
Respiratory distress (difficulty in breathing)
Stevens-johnson syndrome (an immune-complex-mediated hypersensitivity disorder. it ranges from mild skin and mucous membrane lesions to a severe)
Urinary tract infection
Cerebral oedema (swelling of brain)
Drug effect decreased
Muscle contractions involuntary (uncontrolled muscle contraction)
Hypotension (abnormally low blood pressure)

What are the existing conditions these people have? *

Convulsion (muscles contract and relax rapidly and repeatedly, resulting in an uncontrolled shaking of the body): 11 people, 15.94%
Multiple Myeloma (cancer of the plasma cells): 9 people, 13.04%
Percutaneous Coronary Intervention: 4 people, 5.80%
Heart Disease: 4 people, 5.80%
Glioblastoma Multiforme (most common and deadliest of malignant primary brain tumours in adults): 4 people, 5.80%
Arrhythmias (irregular heartbeat): 4 people, 5.80%
Alcoholism (problems with alcohol): 4 people, 5.80%

* Approximation only. Some reports may have incomplete information.

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