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

Summary:

Drug interactions are reported among people who take Theo-dur (theophylline) and Lopressor (metoprolol tartrate). Common drug interactions include injection site pain among females and cerebrovascular accident among males.

The phase IV clinical study analyzes what interactions people have when they take Theo-dur and Lopressor. It is created by eHealthMe based on reports of 28 people who take the same drugs from the FDA, and is updated regularly.

What is Theo-dur?

Theo-dur has active ingredients of theophylline. It is often used in asthma. eHealthMe is studying from 4,451 Theo-dur users. Check the latest studies of Theo-dur.

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 Sep, 02, 2026

28 people who take Theo-dur and Lopressor together, and have interactions are studied.

Theo-dur and Lopressor drug interactions.

What are the common drug interactions of Theo-Dur and Lopressor, by gender? *:

female:

Injection site pain
Injection site swelling
Oedema lower limb (fluid collection in tissue of lower leg)
Oral candidiasis (fungal infection of mouth)
Peritonitis (inflammation of the peritoneum, the thin tissue that lines the inner wall of the abdomen and covers most of the abdominal organs)
Tremor (trembling or shaking movements in one or more parts of your body)
Vision blurred
Dysphonia (speech disorder attributable to a disorder of phonation)
Hiatus hernia (hernia resulting from the protrusion of part of the stomach through the diaphragm)
Back pain

male:

Cerebrovascular accident (sudden death of some brain cells due to lack of oxygen when the blood flow to the brain is impaired by blockage or rupture)
Myocardial infarction (destruction of heart tissue resulting from obstruction of the blood supply to the heart muscle)
Nephropathy (damage to or disease of a kidney)
Neuropathy (damage to nerves)
Pneumonia
Renal failure chronic (long lasting kidney dysfunction)
Retinopathy (acute damage to the retina of the eye)
Sinus arrhythmia (a naturally occurring variation in heart rate that occurs during a breathing cycle)
Transaminases increased
Agitation (state of anxiety or nervous excitement)

What are the common drug interactions of Theo-Dur 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:

Pruritus (severe itching of the skin)
Swelling
Dyspnoea (difficult or laboured respiration)
Nausea (feeling of having an urge to vomit)

40-49:

Anaemia (lack of blood)
Back pain
Bipolar disorder (mood disorder)
Candidiasis (candidiasis or thrush is a fungal infection)
Coronary artery disease (plaque building up along the inner walls of the arteries of the heart, which narrows the arteries and restricts blood flow to the heart)
Deep vein thrombosis (blood clot in a major vein that usually develops in the legs and/or pelvis)
Drug hypersensitivity
Dysphonia (speech disorder attributable to a disorder of phonation)
Essential hypertension (primary hypertension)
Hiatus hernia (hernia resulting from the protrusion of part of the stomach through the diaphragm)

50-59:

Cerebrovascular accident (sudden death of some brain cells due to lack of oxygen when the blood flow to the brain is impaired by blockage or rupture)
Myocardial infarction (destruction of heart tissue resulting from obstruction of the blood supply to the heart muscle)
Blood glucose decreased
Cardiac failure
Diabetes mellitus inadequate control
Hypoglycaemia (deficiency of glucose in the bloodstream)
Hyponatraemia (abnormally low level of sodium in the blood; associated with dehydration)
Hypotension (abnormally low blood pressure)
Lipoma (a growth of fatty tissue that slowly develops just under your skin)
Nephropathy (damage to or disease of a kidney)

60+:

Blood glucose increased
Pain
Multi-organ failure (multisystem organ failure)
Renal failure (kidney dysfunction)
Renal impairment (severely reduced kidney function)
Renal injury (kidney injury)
Stress
Angina pectoris (chest pain due to ischemia of the heart muscle)
Asthenia (weakness)
Back pain

What are the existing conditions these people have? *

Dyspnea (difficult or laboured breathing): 7 people, 25.00%
Pain: 6 people, 21.43%
Nausea (feeling of having an urge to vomit): 4 people, 14.29%
Back Pain: 4 people, 14.29%
Restless Leg Syndrome (a powerful urge to move your legs): 3 people, 10.71%
Osteoarthritis (a joint disease caused by cartilage loss in a joint): 3 people, 10.71%
Migraine (headache): 3 people, 10.71%
Headache (pain in head): 3 people, 10.71%
Cough: 3 people, 10.71%
Wheezing (a high-pitched whistling sound made while you breath): 3 people, 10.71%

* Approximation only. Some reports may have incomplete information.

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