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

Summary:

Drug interactions are reported among people who take Silenor (doxepin hydrochloride) and Synthroid (levothyroxine sodium). Common drug interactions include neutropenia among females and drug ineffective among males.

The phase IV clinical study analyzes what interactions people have when they take Silenor and Synthroid. It is created by eHealthMe based on reports of 45 people who take the same drugs from the FDA, and is updated regularly.

What is Silenor?

Silenor has active ingredients of doxepin hydrochloride. It is often used in insomnia. eHealthMe is studying from 635 Silenor users. Check the latest studies of Silenor.

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, 20, 2026

45 people who take Silenor and Synthroid together, and have interactions are studied.

Silenor and Synthroid drug interactions.

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

female:

Neutropenia (an abnormally low number of neutrophils)
Vomiting
Abdominal distension
Abdominal pain upper
Alopecia (absence of hair from areas of the body)
Back pain
Diarrhoea
Diverticulitis (digestive disease which involves the formation of pouches (diverticula) within the bowel wall)
White blood cell count decreased
Blood urine present

male:

Drug ineffective
Hypertension (high blood pressure)
Nervousness
Seizure (abnormal excessive or synchronous neuronal activity in the brain)
Sinus disorder (disease of sinus)

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

0-1:

n/a

2-9:

n/a

10-19:

n/a

20-29:

n/a

30-39:

Anxiety
Hypertension (high blood pressure)
Back pain
Pneumonia
Bronchitis (inflammation of the mucous membrane in the bronchial tubes)
Heart rate increased
Malaise (a feeling of general discomfort or uneasiness)

40-49:

Drug ineffective
Bladder spasm
Blood creatine phosphokinase increased
Bronchitis (inflammation of the mucous membrane in the bronchial tubes)
Dyspepsia (indigestion)
Dysuria (painful or difficult urination)
Fatigue (feeling of tiredness)
Haemorrhage (bleeding)
Injection site reaction
Iron deficiency

50-59:

Alopecia (absence of hair from areas of the body)
Hair colour changes
Hair disorder
Appendicitis (inflammation of the appendix)
Blood urine present
Dysuria (painful or difficult urination)
Enteritis infectious (infection with feline parvovirus (fpv), also known as feline panleucopenia virus)
Muscle spasms (muscle contraction)
Neutropenia (an abnormally low number of neutrophils)
Neutrophil count decreased (less than normal number of neutrophil a type of blood cell)

60+:

Fatigue (feeling of tiredness)
Nasopharyngitis (inflammation of the nasopharynx)
Alopecia (absence of hair from areas of the body)
Amnesia (deficit in memory caused by brain damage, disease, or psychological trauma)
Anxiety
Arthralgia (joint pain)
Blood immunoglobulin g increased
Cerebral atrophy (decrement in size of brain)
Depressed mood
Disturbance in attention

What are the existing conditions these people have? *

Narcolepsy (brain's inability to regulate sleep-wake cycles normally): 22 people, 48.89%
Cataplexy (loss of muscle tone accompanied by full conscious awareness): 16 people, 35.56%
Nausea (feeling of having an urge to vomit): 5 people, 11.11%
Muscle Aches (muscle pain): 5 people, 11.11%
Joint Pain: 5 people, 11.11%
Diarrhea: 5 people, 11.11%
Neuropathy Peripheral (surface nerve damage): 4 people, 8.89%
Mucosal Inflammation (infection of mucous membrane): 4 people, 8.89%
High Blood Pressure: 4 people, 8.89%
Breast Cancer Metastatic: 4 people, 8.89%

* Approximation only. Some reports may have incomplete information.

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