Doxylamine + Folic Acid + Vitamin B6

Usage

• This drug is primarily prescribed for the management of nausea and vomiting during pregnancy (NVP), often referred to as “morning sickness.” It may also be used to treat hyperemesis gravidarum (HG), a severe form of NVP characterized by persistent nausea and vomiting leading to dehydration, weight loss, and electrolyte imbalances. Folic acid supplementation supports fetal development.
• Pharmacological Classification: Antiemetic, Antihistamine (Doxylamine), Vitamin Supplement (B6 and Folic acid)

Alternate Names

• Doxylamine Succinate + Pyridoxine Hydrochloride + Folic Acid
• Brand Names: Diclegis (US), Bonjesta (US), Doxinate (India), Doxylamine-Pyridoxine-Folic Acid (generic)

How It Works

• Pharmacodynamics: Doxylamine, an antihistamine, antagonizes H1 receptors in the vestibular system and the chemoreceptor trigger zone (CTZ) in the brain, reducing nausea and vomiting. Pyridoxine (Vitamin B6) plays a role in neurotransmitter synthesis, potentially modulating nausea pathways. Folic acid is crucial for cell growth and development, especially during pregnancy for neural tube development.
• Pharmacokinetics: Doxylamine is well-absorbed orally and metabolized in the liver. Pyridoxine is also absorbed orally and converted to its active form, pyridoxal 5’-phosphate. Folic acid is absorbed primarily in the small intestine. All components are likely renally excreted, although precise elimination pathways for doxylamine metabolites need more clinical research.

Dosage

Standard Dosage

Adults (For NVP/HG):

• Initial: Two tablets at bedtime.
• If symptoms persist: Two tablets at bedtime and one tablet in the morning on Day 2. May increase to a maximum of four tablets daily (1 morning, 1 mid-afternoon, 2 bedtime) as needed. Please note that Diclegis is formulated as delayed-release tablets, and Bonjesta is formulated as extended-release tablets.

Children: This combination is not recommended for children.

Special Cases:

• Elderly Patients: No specific dosage adjustments are mentioned in the sources, but caution is advised due to potential for increased sensitivity.
• Patients with Renal/Hepatic Impairment: Exercise caution and consider dosage adjustments. Consult a nephrologist/hepatologist for precise guidance.
• Patients with Comorbid Conditions: Use with caution in asthma, glaucoma, peptic ulcer, gastrointestinal obstruction, urinary retention, and Vitamin B12 deficiency.

Clinical Use Cases (Not applicable for this drug)

• The combination of doxylamine, folic acid, and pyridoxine is specifically indicated for NVP/HG. Its use in settings like intubation, surgical procedures, mechanical ventilation, ICU, or emergency situations is not relevant.

Dosage Adjustments

• Dosage adjustments are made empirically based on symptom control, starting low and titrating upwards.

Side Effects

Common Side Effects

• Drowsiness
• Dizziness
• Dry mouth
• Constipation
• Fatigue
• Headache

Rare but Serious Side Effects

• Blurred vision
• Difficulty urinating
• Confusion
• Seizures

Contraindications

• Hypersensitivity to doxylamine, pyridoxine, or folic acid
• Concomitant use of monoamine oxidase inhibitors (MAOIs)

Drug Interactions

• Alcohol (increased drowsiness)
• CNS depressants (additive sedative effects)
• Anticholinergic drugs (additive anticholinergic effects)
• Folate-rich foods (potential interference with absorption, though data is lacking).

Pregnancy and Breastfeeding

• Generally considered safe for use during pregnancy (FDA Pregnancy Category A for Diclegis, Category B for Vitamin B6 and folic acid).
• Not recommended during breastfeeding due to potential for excretion in breast milk and effects on the infant.

Drug Profile Summary

• Mechanism of Action: Doxylamine antagonizes H1 receptors; pyridoxine may modulate neurotransmitters; folic acid supports fetal development.
• Side Effects: Drowsiness, dizziness, dry mouth, constipation.
• Contraindications: Hypersensitivity, MAOI use.
• Drug Interactions: Alcohol, CNS depressants, anticholinergics.
• Pregnancy & Breastfeeding: Safe in pregnancy; not recommended while breastfeeding.
• Dosage: Start with two tablets at bedtime, titrate up to four as needed.
• Monitoring Parameters: Monitor for symptom control, side effects, and fetal development.

Popular Combinations (Not applicable for this drug)

• This combination is typically used alone for NVP.

Precautions

• Pre-existing medical conditions should be evaluated.
• Avoid alcohol.
• Caution in driving or operating machinery.

FAQs

Q1: What is the recommended dosage for Doxylamine + Folic Acid + Vitamin B6?

A: Initial dose is two tablets at bedtime. This can be increased up to four tablets/day based on symptom control.

Q2: Is this combination safe during pregnancy?

A: Yes, it is generally considered safe for use during pregnancy. Diclegis and Bonjesta are specifically formulated for this indication.

Q3: Can I take this while breastfeeding?

A: It is not recommended to use this combination while breastfeeding.

Q4: What are the common side effects?

A: The most common side effects include drowsiness, dry mouth, dizziness, and constipation.

Q5: What should I do if I miss a dose?

A: Take the missed dose as soon as you remember, unless it is close to the time for your next dose. Do not double the dose.

Q6: Can I drink alcohol while taking this medication?

A: No, alcohol should be avoided as it can exacerbate drowsiness.

Q7: Are there any drug interactions I should be aware of?

A: Yes, this combination can interact with CNS depressants, anticholinergics, and MAOIs. Consult a doctor if you are taking other medications.

Q8: What is the mechanism of action of this medication?

A: Doxylamine acts as an antihistamine by blocking the H1 receptors, which are known to control nausea, vomiting, and dizziness. Vitamin B6 and folic acid supplements treat nausea, vomiting, and aid in the production of healthy red blood cells.

Q9: How should this medication be stored?

A: Store this medication in a cool, dry place away from direct sunlight.

Q10: What if the symptoms persist after taking this medication?

A: Consult your doctor if the medication does not provide symptom relief. You may require other interventions to manage nausea and vomiting during pregnancy.