Synthroid and Dynacirc drug interactions - a phase IV clinical study of FDA data

Summary:

Drug interactions are reported among people who take Synthroid (levothyroxine sodium) and Dynacirc (isradipine). Common drug interactions include hypertension among females and anaemia among males.

The phase IV clinical study analyzes what interactions people have when they take Synthroid and Dynacirc. It is created by eHealthMe based on reports of 73 people who take the same drugs from the FDA, and is updated regularly.

What is Synthroid?

Synthroid has active ingredients of levothyroxine sodium. It is often used in hypothyroidism. eHealthMe is studying from 249,202 Synthroid users. Check the latest studies of Synthroid.

What is Dynacirc?

Dynacirc has active ingredients of isradipine. eHealthMe is studying from 975 Dynacirc users. Check the latest studies of Dynacirc.

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, 27, 2026

73 people who take Synthroid and Dynacirc together, and have interactions are studied.

Synthroid and Dynacirc drug interactions.

What are the common drug interactions of Synthroid and Dynacirc, by gender? *:

female:

Hypertension (high blood pressure)
Surgery
Dizziness
Abdominal pain upper
Anaemia (lack of blood)
Cataract cortical (it affects outer part of lens)
Impaired work ability
Iron deficiency anaemia
Lobar pneumonia (a form of pneumonia that affects a large and continuous area of the lobe of a lung)
Renal failure chronic (long lasting kidney dysfunction)

male:

Anaemia (lack of blood)
Asthenia (weakness)
Central nervous system lymphoma (cancer of central nervous system forms in lymph tissue)
Completed suicide (act of taking one's own life)
Cytomegalovirus infection
Gastrointestinal haemorrhage (bleeding gastrointestinal tract)
Leukopenia (less number of white blood cells in blood)
Mental status changes (general changes in brain function, such as confusion, amnesia (memory loss), loss of alertness, loss of orientation)
Neutropenia (an abnormally low number of neutrophils)

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

0-1:

n/a

2-9:

n/a

10-19:

Headache (pain in head)
Hypertension (high blood pressure)
Paraesthesia (sensation of tingling, tickling, prickling, pricking, or burning of a person's skin with no apparent long-term physical effect)
Rhinorrhoea (watery mucus discharge from the nose)
Nystagmus (a condition of involuntary eye movement)
Pharyngitis streptococcal (inflammation of the pharynx caused by infection from. streptococcus)
Renal mass (mass in kidney)
Renal neoplasm (kidney tumour)
Angiomyolipoma (most common benign tumour of the kidney)

20-29:

Cardiac arrest
Cardiac failure congestive
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)
Oropharyngeal pain
Pyrexia (fever)
Respiratory tract congestion (blockage on respiratory system)
Respiratory tract infection
Sinus congestion (blockage of sinus)
Transient ischaemic attack (a transient episode of neurologic dysfunction caused by ischemia (loss of blood flow))

30-39:

n/a

40-49:

Constipation
Dizziness
Dry mouth
Dyspepsia (indigestion)
Dyspnoea (difficult or laboured respiration)
Flushing (the warm, red condition of human skin)
Heart rate increased
Hyperhidrosis (abnormally increased sweating)
Nausea (feeling of having an urge to vomit)
Nervousness

50-59:

Visual acuity reduced (reduced clearness of vision)
Abdominal pain
Abdominal pain upper
Acidosis (build-up of carbon dioxide in the blood)
Hyperkalaemia (damage to or disease of the kidney)
Hyperlipidaemia (presence of excess lipids in the blood)
Multiple injuries
Nephritis (inflammation of the nephrons in the kidneys)
Renal failure acute (rapid kidney dysfunction)
Diabetes mellitus (diabetes, caused by a deficiency of the pancreatic hormone insulin)

60+:

Dizziness
Weight decreased
Dyspnoea (difficult or laboured respiration)
Rash
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)
Cholelithiasis (the presence or formation of gallstones in the gallbladder or bile ducts)
Constipation
Decreased appetite
Fatigue (feeling of tiredness)
Hypoglycaemia (deficiency of glucose in the bloodstream)

What are the existing conditions these people have? *

High Blood Pressure: 12 people, 16.44%
Osteoporosis (bones weak and more likely to break): 7 people, 9.59%
Type 2 Diabetes: 4 people, 5.48%
Pain: 4 people, 5.48%
Hypopituitarism (diminished hormone secretion by the pituitary gland, causing dwarfism in children and premature aging in adults): 4 people, 5.48%
Cardiac Failure Congestive: 4 people, 5.48%

* Approximation only. Some reports may have incomplete information.

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