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

Summary:

Drug interactions are reported among people who take Carnitor (levocarnitine) and Synthroid (levothyroxine sodium). Common drug interactions include asthenia among females and hypotension among males.

The phase IV clinical study analyzes what interactions people have when they take Carnitor and Synthroid. It is created by eHealthMe based on reports of 60 people who take the same drugs from the FDA, and is updated regularly.

What is Carnitor?

Carnitor has active ingredients of levocarnitine. eHealthMe is studying from 894 Carnitor users. Check the latest studies of Carnitor.

What is Synthroid?

Synthroid has active ingredients of levothyroxine sodium. It is often used in hypothyroidism. eHealthMe is studying from 249,198 Synthroid users. Check the latest studies of Synthroid.

On Jul, 22, 2026

60 people who take Carnitor and Synthroid together, and have interactions are studied.

Carnitor and Synthroid drug interactions.

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

female:

Asthenia (weakness)
Atrial fibrillation (fibrillation of the muscles of the atria of the heart)
Bacteraemia (presence of bacteria in the blood)
Blood pressure decreased
Cachexia (loss of weight)
Chest pain
Clumsiness (a lack of coordination or elegance)
Confusional state
Emphysema (chronic respiratory disease - over inflation of the air sacs (alveoli) in the lungs)
Fatigue (feeling of tiredness)

male:

Hypotension (abnormally low blood pressure)
Respiratory failure (inadequate gas exchange by the respiratory system)
Aortic stenosis (obstruction to the outflow of blood from the left ventricle into the aorta)
Aortic valve disease
Aplasia pure red cell (type of anaemia affecting the precursors to red blood cells but not to white blood cells)
Ascites (accumulation of fluid in the abdominal cavity)
Asthenia (weakness)
Autism (a mental condition, present from early childhood, characterized by difficulty in communicating and forming relationships with other people and in using language and abstract concepts)
Back pain
Blood cholesterol increased

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

0-1:

n/a

2-9:

Abnormal behaviour
Anxiety
Bruxism (habitual grinding of the teeth, typically during sleep)
Dermatillomania (skin picking disorders)
Disturbance in attention
Ear infection
Hypotonia (low muscle tone)
Increased appetite
Nail picking
Obsessive-compulsive disorder (an anxiety disorder characterized by intrusive thoughts that produce uneasiness, apprehension, fear, or worry;)

10-19:

Abnormal behaviour
Autism (a mental condition, present from early childhood, characterized by difficulty in communicating and forming relationships with other people and in using language and abstract concepts)
Blood cholesterol increased
Brain neoplasm (tumour of brain)
Neoplasm progression (growth of tumour)
Scoliosis (a medical condition in which a person's spine is curved from side to side)
Anaphylactic reaction (serious allergic reaction)
Choking sensation (feeling of obstruction in respiratory system)
Death
Diarrhoea

20-29:

Seizure (abnormal excessive or synchronous neuronal activity in the brain)
Aggression

30-39:

Anorexia (eating disorder characterized by immoderate food restriction and irrational fear of gaining weight)
Cardiomyopathy (weakening of the heart muscle)
Infection
Personality disorder
Rhabdomyolysis (a condition in which damaged skeletal muscle tissue breaks down)

40-49:

Oedema (fluid collection in tissue)
Hypoglycaemia (deficiency of glucose in the bloodstream)
Surgery

50-59:

Mitral valve disease (disease of mitral valve of heart)
Muscle spasms (muscle contraction)
Pneumonia
Pulmonary oedema (fluid accumulation in the lungs)
Pyrexia (fever)
Renal failure (kidney dysfunction)
Renal failure chronic (long lasting kidney dysfunction)
Respiratory failure (inadequate gas exchange by the respiratory system)
Sepsis (a severe blood infection that can lead to organ failure and death)
Staphylococcal bacteraemia (a bacterial infection of blood)

60+:

Dizziness
Dyspnoea (difficult or laboured respiration)
Atrial fibrillation (fibrillation of the muscles of the atria of the heart)
Bacteraemia (presence of bacteria in the blood)
Blood pressure decreased
Cachexia (loss of weight)
Emphysema (chronic respiratory disease - over inflation of the air sacs (alveoli) in the lungs)
Fatigue (feeling of tiredness)
Hypercapnia (too much smoke)
Hypertension (high blood pressure)

What are the existing conditions these people have? *

Cataplexy (loss of muscle tone accompanied by full conscious awareness): 10 people, 16.67%
Narcolepsy (brain's inability to regulate sleep-wake cycles normally): 10 people, 16.67%
Thyroid Diseases: 5 people, 8.33%
Growth Hormone Deficiency: 5 people, 8.33%
Blood Pressure Abnormal: 4 people, 6.67%
Humoral Immune Defect (impairment of humoral immunity): 3 people, 5.00%
Asthma: 3 people, 5.00%
Carnitine Deficiency: 3 people, 5.00%
Constipation: 3 people, 5.00%
Hypogonadism (reduction or absence of hormone secretion or other physiological activity of the gonads (testes or ovaries)): 3 people, 5.00%

* Approximation only. Some reports may have incomplete information.

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