Valproic acid and Zanaflex drug interactions - a phase IV clinical study of FDA data

Summary:

Drug interactions are reported among people who take Valproic acid (valproic acid) and Zanaflex (tizanidine hydrochloride). Common drug interactions include syncope among females and depressed level of consciousness among males.

The phase IV clinical study analyzes what interactions people have when they take Valproic acid and Zanaflex. It is created by eHealthMe based on reports of 8 people who take the same drugs from the FDA, and is updated regularly.

What is Valproic acid?

Valproic acid has active ingredients of valproic acid. It is often used in epilepsy. eHealthMe is studying from 36,193 Valproic acid users. Check the latest studies of Valproic acid.

What is Zanaflex?

Zanaflex has active ingredients of tizanidine hydrochloride. It is often used in muscle spasms. eHealthMe is studying from 17,475 Zanaflex users. Check the latest studies of Zanaflex.

On Jan, 31, 2026

8 people who take Valproic acid and Zanaflex together, and have interactions are studied.

Valproic acid and Zanaflex drug interactions.

What are the common drug interactions of Valproic Acid and Zanaflex, by gender? *:

female:

Syncope (loss of consciousness with an inability to maintain postural tone)
Abdominal pain lower
Chest discomfort
Chest pain
Hospitalisation
Increased appetite
Increased tendency to bruise (increased tendency to injure the underlying soft tissue or bone)
Kidney infection
Maternal exposure before pregnancy (use of substance before pregnancy)
Multiple drug overdose

male:

Depressed level of consciousness
Heart rate increased
Hypotension (abnormally low blood pressure)
Musculoskeletal stiffness (stiffness of the body's muscles, joints, tendons, ligaments and nerves)
Pallor
Sedation
Somnolence (a state of near-sleep, a strong desire for sleep)

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

0-1:

n/a

2-9:

n/a

10-19:

Depressed level of consciousness
Somnolence (a state of near-sleep, a strong desire for sleep)
Adverse drug reaction
Agitation (state of anxiety or nervous excitement)
Arthralgia (joint pain)
Asthenia (weakness)
Blood pressure decreased
Bradycardia (abnormally slow heart action)
Constipation
Dehydration (dryness resulting from the removal of water)

20-29:

Abdominal pain lower
Headache (pain in head)
Hospitalisation
Increased appetite
Kidney infection
Maternal exposure before pregnancy (use of substance before pregnancy)
Nausea (feeling of having an urge to vomit)
Nephrolithiasis (calculi in the kidneys)
Pregnancy
Sleep disorder

30-39:

n/a

40-49:

n/a

50-59:

Chest discomfort
Chest pain
Wheezing (a high-pitched whistling sound made while you breath)
Headache (pain in head)
Increased tendency to bruise (increased tendency to injure the underlying soft tissue or bone)
Multiple drug overdose
Pain in extremity
Pulmonary embolism (blockage of the main artery of the lung)
Respiratory failure (inadequate gas exchange by the respiratory system)
Syncope (loss of consciousness with an inability to maintain postural tone)

60+:

n/a

* Approximation only. Some reports may have incomplete information.

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