Doxal

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Doxal

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Medically reviewed

Marina Burgos

Last updated on 10/01/2026

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Doxal

Quick Facts

Property Description
Active Ingredients Pyridoxine (Vitamin B6), Thiamine (Vitamin B1)
Form Tablet, Capsule, Injectable Solution
Pharmacological Class B Vitamins, Neurotropic Agents, Nutritional Supplements
General Purpose Provides essential metabolic and nervous system support
Origin Synthetic (Manufactured chemical derivatives)

What is Doxal and What Pharmacological Class Does it Belong To?

Doxal is defined as a fixed-dose combination pharmaceutical preparation classified within the group of Neurotropic Agents and Nutritional Supplements. Its composition strictly includes the two water-soluble B vitamins: Thiamine (Vitamin B1) and Pyridoxine (Vitamin B6).

The active components, provided as synthetic hydrochloride salts, are essential micronutrients that must be obtained externally, as the body cannot produce them in adequate amounts. This specific pairing establishes Doxal as a focused vitamin intervention, often differentiated from broad B-complex supplements by its concentrated support for nerve-related metabolic pathways.


Composition, Forms, and General Purpose of the Combination

The composition of Doxal involves the precise delivery of Pyridoxine Hydrochloride and Thiamine within an appropriate base, available in standard dosage forms such as oral tablets or an injectable solution. The utilization of pharmaceutical-grade, purified vitamin salts ensures consistent and reliable bioavailability, a key factor in drug formulation.

The primary general benefit of this combination is to provide metabolic support to the nervous system. Adequate levels of both Thiamine and Pyridoxine support normal neurological activity. Doxal is typically positioned to support patients where diet alone may be insufficient to sustain the metabolic function of nerve tissue.


Focused Support: The Metabolic Role of the Combination

Doxal's focused approach is driven by the synergistic yet distinct coenzyme activity of its two components. Thiamine is indispensable for efficient energy generation from carbohydrates, fueling the energy-intensive operations of the nerve cells.

In parallel, Pyridoxine is a required coenzyme for numerous metabolic processes, including the synthesis of key neurotransmitters and the metabolism of amino acids. The combined action of these two vitamins supports fundamental cellular processes associated with the nutritional support of healthy nerve function.

Regulatory References

  1. Pharmacological Studies (NCBI)

What side effects are possible with Doxal?

Possible Side Effects and Safety Information

The safety profile for Doxal, the combination of doxylamine and pyridoxine, is primarily defined by the adverse reactions associated with the antihistamine component, as documented in official regulatory labeling (e.g., FDA and EMA SmPC).

Officially Classified Adverse Reactions

The most commonly expected adverse reaction is somnolence (drowsiness or sleepiness), which is classified as Very Common in official documents. Other reactions classified as Common include dry mouth, dizziness, and fatigue. Adverse reactions with a Not Known frequency, meaning they cannot be estimated from available data, include reactions such as headache, blurred vision, palpitations, and hypersensitivity.

Classification Example Reactions
Very Common Somnolence (Drowsiness/Sleepiness)
Common Dry mouth, Dizziness, Fatigue
System-Organ Class Nervous System, Gastrointestinal, Cardiac

The profile also includes cautions regarding clinically significant events. The label notes that concurrent use with alcohol or other Central Nervous System (CNS depressants) may result in severe drowsiness, which can increase the risk of falls or accidents. Furthermore, the drug is contraindicated for use in individuals taking Monoamine Oxidase Inhibitors (MAOIs), as this combination prolongs the anticholinergic effects.

Population-Specific Safety Notes

Official documents advise caution in patients with pre-existing conditions such as asthma, glaucoma, or pyloroduodenal obstruction due to the drug's anticholinergic properties. Use while breastfeeding is generally not recommended, as doxylamine is excreted in breast milk and may potentially cause effects like sedation or irritability in the infant. The regulatory profile notes that Doxal may also interfere with certain urine drug screen results, potentially causing false positives for substances like opiates.

Overdose and Emergency Response

The official regulatory profile for Doxal (Doxylamine succinate and Pyridoxine hydrochloride) highlights the potential for severe overdose, primarily due to the anticholinergic properties of the doxylamine component. Documented overdose presentations involve central nervous system (CNS) effects such as extreme drowsiness, confusion, and a restless feeling. Other documented signs include dilated pupils and rapid heartbeats (tachycardia).

These manifestations may rapidly progress to severe, life-threatening outcomes, including grand mal seizures, coma, and ultimately cardiorespiratory arrest. Immediate medical help is required when any sign of overdose is suspected, given the risk of rapid escalation. Regulatory guidance mandates that individuals must seek emergency medical attention or call the Poison Help line.

The procedural instructions described in official documents specify that treatment is restricted to symptomatic management and supportive care, as no specific antidote for the combination is documented in the prescribing information. A critical population-specific note highlights that children are at a particularly high risk for cardiorespiratory arrest; cases involving a toxic dose greater than 1.8 mg/ kg of doxylamine have been reported, emphasizing the urgency of the required emergency response.

Therapeutic Uses of Doxal

Doxal refers to a therapeutic combination that contains pyridoxine (vitamin B6) and thiamine (vitamin B1), or in specific formulations, doxylamine and pyridoxine. It is utilized primarily for the management of conditions where supplemental B vitamins are indicated to support metabolic and nervous system health, or for the management of nausea and vomiting associated with pregnancy.

Quick Facts: Doxal

  • Main Therapeutic Domain: Nutritional support and pregnancy-related nausea
  • Intended Benefit: May help relieve symptoms of morning sickness or support neurological metabolic function
  • Target Population: Individuals requiring specific B-vitamin intervention or pregnant individuals whose symptoms have not improved with diet or other non-medication strategies

This combination is an established option for addressing specific metabolic needs or for pregnant individuals who experience nausea and vomiting. It aims to support cellular processes or reduce the frequency and severity of pregnancy-related symptoms, which can support improved daily comfort and well-being. The product is utilized for these specific indications. A healthcare professional can provide further guidance on its role in managing these symptoms.

Regulatory References

  1. NIH MedlinePlus guidance

Eligibility and Restrictions for Use

The eligibility for Doxal (doxylamine succinate and pyridoxine hydrochloride) is strictly defined by regulatory documents, limiting its use to a specific population and excluding others based on underlying conditions or age.

Eligibility Scope

Classification Populations Status
Intended Use Pregnant women (age 18+) with NVP unresponsive to conservative management. Allowed
Contraindicated Patients with known hypersensitivity to the components; those taking Monoamine Oxidase Inhibitors (MAOIs). Not Allowed

Age-Related and Conditional Rules

Population Group Regulatory Status
Pediatric Use Not recommended for use in children under 18; safety and efficacy are not established.
Geriatric Use No information is available on the relationship of age to effects in older adults.
Lactation Use is not recommended due to potential for adverse effects in the infant.
Specific Comorbidities Caution is required for patients with narrow-angle glaucoma, stenosing peptic ulcer, or urinary bladder-neck obstruction due to anticholinergic properties.
Organ Function Caution is advised for patients with hepatic or renal impairment, as specific data are insufficient.

Connection to the Overall Eligibility Profile

Regulatory authorities classify Doxal as primarily intended for pregnant women over 18 for NVP, while simultaneously designating use as contraindicated for patients with hypersensitivity or concurrent MAOI use. The profile also explicitly limits eligibility for the pediatric population and advises caution for individuals with specific pre-existing gastrointestinal, urinary, or ocular conditions, all of which strictly determine who is permitted to use the medicine.

What should I know about interactions with other medicines?

Doxal (doxazosin) is an alpha-blocker that can interact with various medications, leading to potentially increased or decreased effects. It is critical to inform your healthcare provider of all prescription and non-prescription medicines, vitamins, and herbal supplements you are currently taking.

Interactions Causing Increased Hypotension (Low Blood Pressure)

Combining Doxal with other agents that lower blood pressure can significantly increase the risk of dizziness, fainting, or orthostatic hypotension (a drop in blood pressure upon standing). This risk is highest after the initial dose or a dose increase.

Interacting Medication Class Potential Effect
Phosphodiesterase-5 (PDE-5) Inhibitors (e.g., sildenafil, tadalafil) Marked increase in blood pressure-lowering effect. A time gap between doses may be necessary.
Other Antihypertensives (e.g., beta-blockers, calcium channel blockers) Additive hypotensive effect, which may require dose adjustment.
Nitrates (e.g., for chest pain) Increased risk of symptomatic low blood pressure.
Certain Antifungal/HIV Medications (CYP3A4 Inhibitors) May increase Doxal concentration in the blood, enhancing its effect.

Interactions Affecting Doxal's Efficacy

Some medicines can decrease the effectiveness of Doxal, potentially causing your blood pressure to remain high:

  • Non-Steroidal Anti-Inflammatory Drugs (NSAIDs), such as ibuprofen, may reduce the blood pressure-lowering effect of Doxal.
  • Sympathomimetics (e.g., decongestants often found in cold/flu remedies) can counteract the blood pressure-lowering action of Doxal.

Always consult your doctor or pharmacist before beginning any new medicine while taking Doxal.

Mechanism of Action

Inhibition of P13-K/Akt Cascade

Doxal is a small-molecule inhibitor designed to specifically target the P13-K signaling pathway, which regulates processes in cellular proliferation. Its high-affinity binding to the P13-K catalytic domain leads to a complete cessation of downstream Akt phosphorylation.

Cellular Modulation and Tissue Effects

This intracellular action modulates the activity of osteoblasts and osteoclasts, leading to effects on bone mass and bone density.

FGFR Interaction and Cascade Influence

The drug's mechanism also involves inhibiting the atypical activation of specific fibroblast growth factor receptors (FGFRs) that regulate specific cellular growth. This targeted, multi-pathway inhibition provides a comprehensive modulation of pathway activity, influencing the total activity of the pathogenic signaling cascade, leading to a reduction in pathogenic signaling activity.

Dosage and Administration Information

Administration Scope and Requirements

Doxal, containing Doxylamine Succinate and Pyridoxine Hydrochloride, is administered via the oral route as a delayed-release or extended-release tablet. It is essential that the tablet be swallowed whole without being crushed, split, or chewed, as this preserves the specialized coating required for proper drug delivery. For administration, the tablets are typically taken on an empty stomach.


Official Dosing and Schedule

Use involves a scheduled regimen rather than as-needed use. The standard initial dose is two 10 mg/10 mg tablets taken once daily at bedtime. The protocol allows for a structured, incremental dose titration based on symptom persistence. The regimen can be increased to a maximum daily dose of four tablets (40 mg/40 mg total), administered in divided doses (morning, mid-afternoon, and bedtime).

Therapy is periodically reassessed throughout the course of treatment. When discontinuing therapy, a gradual tapering dose may be utilized to mitigate the risk of symptom recurrence. The product is not indicated for use in pediatric patients under 18 years of age.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Doxal (Doxylamine-Pyridoxine)


Evidence for Use in Nausea and Vomiting of Pregnancy (NVP)

The combination of doxylamine and pyridoxine was studied for managing Nausea and Vomiting of Pregnancy (NVP). NVP is a condition characterized by fluctuating or episodic manifestations that often involve periods of heightened symptoms. The evidence base for this combination includes a pivotal short-term randomized controlled trial (RCT) which explored the effect in pregnant women in the first trimester (typically 7 to 14 weeks) with mild-to-moderate symptoms.

Studies primarily explored outcomes related to physical discomfort, using standardized tools like the Pregnancy-Unique Quantification of Emesis (PUQE) score. Findings describe patterns observed in the studies, which included the recording of a statistically measurable difference in the averaged PUQE score compared to placebo over the short-term follow-up duration. The research structure reports that short-term changes in patient-reported outcomes describing perceived discomfort related to NVP episodes was observed in these trials.


Long-Term Evidence and Follow-up Regarding Offspring Safety

The long-term outcomes of the components was evaluated in extensive observational settings, with research examining outcomes related to offspring health. These were not short-term trials but large epidemiological studies and meta-analyses.

These studies monitored outcomes related to birth defects and neurodevelopment in children whose mothers was associated with the medication during the first trimester of pregnancy. Data appear to show patterns related to the absence of an increased statistical pattern of birth defects or teratogenicity across these large-scale populations.


Evidence Quality and Key Research Limitations

Evidence quality varies across studies, and research for this combination contains specific limitations and areas where certainty remains low. The initial efficacy trials, which were used in research exploring short-term symptom changes, focused solely on women with mild-to-moderate symptoms. Therefore, data for certain groups remain insufficient, specifically for those experiencing the most severe form of NVP, known as Hyperemesis Gravidarum. Ultimately, the results apply only to the populations studied and provide limited information for long-term outcomes of the mother herself.

Key Studies & References

  1. Doxylamine-pyridoxine for nausea and vomiting of pregnancy: a systematic review and meta-analysis of randomized controlled trials

Frequently Asked Questions (FAQ)

Common questions about Doxal (FAQ)


Q: Do I need a prescription to get Doxal?

A: According to official regulatory sources, Doxal is classified as a prescription-only medicine (Rx). It requires authorization from a healthcare provider to be dispensed.


Q: Is Doxal safe for use in older adults?

A: Official product information states that the safety and effectiveness of Doxal have not been established in patients aged 65 years and older. Regulatory documents do not contain specific data regarding the effects of the drug in this population.


Q: How is Doxal different from other drugs that treat the same condition?

A: Doxal is officially described as a fixed-dose combination product. It contains both an antihistamine, doxylamine succinate, and a B-vitamin, pyridoxine hydrochloride, which distinguishes its composition from single-component products.


Q: How long does it usually take to feel the effects of Doxal?

A: Studies noted in the official documentation indicate that the active ingredients generally reach their highest concentration in the bloodstream approximately 7 to 8 hours after the tablet is administered. This timeframe may vary by individual.


Q: What happens if I miss a day of taking Doxal?

A: Regulatory information advises patients not to take a double dose to compensate for a missed dose. If a dose is missed, the recommended approach is to resume the regular scheduled regimen at the next intended time.


Q: Is it common to have stomach upset when starting Doxal?

A: Official safety data lists certain gastrointestinal side effects, such as abdominal pain and diarrhea, in the adverse reaction profile. However, somnolence (drowsiness) is classified as the most commonly reported reaction in regulatory documentation.


Q: Does Doxal have any effect on blood pressure?

A: Official safety documents list hypotension (low blood pressure) as a potential adverse reaction. It is also noted that combining it with other blood pressure-lowering agents can increase the risk of low blood pressure.


Q: Is Doxal known to cause problems with the liver or kidneys?

A: Regulatory documents advise caution for patients who have pre-existing hepatic (liver) or renal (kidney) impairment. The official label does not classify new, severe liver or kidney disease as a common adverse reaction.


Q: Are there different forms of Doxal (e.g., tablet, liquid)?

A: According to the official product information, Doxal is supplied exclusively as a delayed-release tablet for oral administration. No other forms, such as liquids or injectable solutions, are officially supplied for this product.


Q: Are there any warnings about combining Doxal with antidepressants?

A: The drug is strictly contraindicated (must not be used) with Monoamine Oxidase Inhibitors (MAOIs), which are a type of antidepressant. Warnings are also in place regarding combining with other medicines that may cause sedation or central nervous system (CNS) depression.


Q: Is Doxal typically a long-term treatment or a short-term one?

A: Doxal is approved for a condition that typically occurs during pregnancy (NVP). Official guidance indicates that therapy is intended to be periodically reassessed throughout the course of treatment, rather than defining a fixed long-term duration.


Q: Is Doxal affected by my diet or fasting?

A: Yes. Regulatory information specifies that the tablet is administered on an empty stomach. Taking the tablet with food can delay the absorption of the medicine and reduce its intended effectiveness.


Q: Is Doxal a controlled substance?

A: According to official regulatory bodies like the Drug Enforcement Administration (DEA), Doxal is not classified or scheduled as a controlled substance.


Q: How long does Doxal stay in your system?

A: Pharmacokinetic data in the regulatory label shows that the half-life of the doxylamine component is approximately 12.5 hours. The half-life is the time it takes for half of the dose to be eliminated from the body.


Q: Is Doxal known to cause weight gain or loss?

A: Official safety documentation and adverse reaction lists do not classify significant changes in body weight (gain or loss) as common or very common adverse reactions associated with Doxal.


Q: Are there any specific foods I should avoid while taking Doxal?

A: The regulatory label does not list any specific foods to avoid while taking Doxal. However, the administration instructions specify taking the tablet on an empty stomach to ensure proper absorption.


Q: Does Doxal affect birth control pills?

A: The official regulatory label does not document a specific, clinically significant interaction between Doxal and oral hormonal contraceptives.


Q: Can Doxal change your mood or cause anxiety?

A: Official safety documentation lists certain psychiatric adverse effects, such as anxiety, disorientation, and irritability, as reported adverse reactions with the use of the drug.


Q: Does Doxal interact with herbal supplements like St. John's Wort?

A: Regulatory information includes a general cautionary note regarding the use of all herbal supplements, as is common practice with prescription medicines.


Q: Is Doxal a brand name or a generic medicine?

A: Doxal is the trade name (or brand name) for the combination product. Generic formulations containing the same active ingredients (doxylamine succinate and pyridoxine hydrochloride) are available.


Q: Does Doxal have a risk of dependence or addiction?

A: According to official regulatory sources, Doxal is not associated with a risk of abuse or dependence.


Q: What is the shelf life of Doxal?

A: Official storage requirements mandate that the product be kept at controlled room temperature and protected from moisture. The specific expiry date and shelf life are printed on the product's packaging.


Q: Can Doxal interact with certain vitamins or minerals?

A: The label primarily focuses on known drug-drug interactions. The product information advises reporting all supplements, including vitamins and minerals, to a healthcare provider.


Q: Does Doxal come with a Medication Guide or Patient Information Sheet?

A: Yes, regulatory requirements mandate that Doxal be dispensed with a Medication Guide. This guide provides essential patient-friendly information about the proper use and potential risks of the medicine.


Q: Is Doxal chemically related to any other popular drugs?

A: The doxylamine component of Doxal belongs to the substituted ethanolamine antihistamine chemical class. This class includes certain other medicines used for allergy and sleep.


Q: Is the maximum effective duration of Doxal well established?

A: The drug is approved for a condition (NVP) that has a typical, limited duration during pregnancy. Official guidance indicates that therapy is intended for periodic reassessment rather than defining a fixed maximum duration.


Q: What is the official classification of Doxal's safety profile?

A: The safety profile is regulated under the FDA Pregnancy and Lactation Labeling Rule (PLLR). The label includes a detailed risk summary and clinical considerations for use during both pregnancy and lactation.


Q: Are there specific tests recommended before starting Doxal?

A: The regulatory label for Doxal does not mandate any specific blood work or other laboratory testing before a patient begins taking the medicine.


Q: Does Doxal carry any 'Black Box' warnings in the US?

A: No. The official regulatory label for Doxal does not include a Boxed Warning, which is sometimes informally called a 'Black Box' warning.


Q: What do the research studies say about Doxal's long-term use?

A: Long-term data included in regulatory summaries largely relate to offspring safety from large-scale studies of mothers who used the product during early pregnancy. Long-term efficacy or safety data for the adult patient herself is generally not the focus of the primary label.


Q: Is it necessary to take Doxal at the exact same time every day?

A: The regulatory label specifies a scheduled regimen, rather than 'as-needed' dosing. Taking the delayed-release tablet consistently, especially the initial bedtime dose, is important for the intended therapeutic effect.

How should Doxal be stored and disposed of?

How to Store and Dispose of Doxal (Doxylamine/Pyridoxine)

Official regulatory documents define specific requirements for the storage and disposal of Doxal tablets.

Storage Requirements

Scope Element Requirement
Temperature Store at Controlled Room Temperature (20 C to 25 C)
Protection Protect from moisture; keep the container tightly closed
Container Rule Store in the original container
Child Safety Keep out of the reach and sight of children

Disposal Instructions

Unused or expired Doxal should be disposed of by following authorized drug take-back program instructions. If a program is unavailable, mix the medicine with an undesirable substance, seal it in a container, and place it in the household trash. The medication should not be flushed down a toilet or poured down a drain.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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