Dimetapp Infant

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Dimetapp Infant

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Medically reviewed

Rosario Oropesa

Last updated on 22/12/2025

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 Dimetapp Infant

Property Description
Active Ingredients Brompheniramine maleate, Phenylephrine Hydrochloride
Form Oral solution (Infant drops)
Pharmacological Class Fixed-dose combination of Antihistamine and Decongestant
Common Use Relief of infant cold and allergy symptoms
Origin Synthetic

What is Dimetapp Infant and Its Purpose?

Dimetapp Infant is classified as an Over-the-counter (OTC) pediatric cold and allergy preparation, manufactured and specifically formulated as a combination product for infants. Its distinctive feature is its positioning and formulation as a liquid infant drops medicine, differentiating it from versions intended for older children. This medicine is based on synthetic chemical compounds and its primary function is to provide multisymptom relief from the discomforts associated with upper respiratory tract issues. The pharmacological classification of its active ingredients relates to their therapeutic use in the management of allergic rhinitis and common cold symptoms. This dual-action class is clinically recognized for treating the simultaneous presentation of nasal congestion and rhinorrhea.


Composition: A Combination of Active Ingredients

The medicine contains two active ingredients: the antihistamine Brompheniramine maleate and the sympathomimetic amine decongestant Phenylephrine Hydrochloride. Brompheniramine functions as a first-generation antihistamine, targeting the excessive fluid production and irritation linked to allergic responses. Phenylephrine Hydrochloride is classified as an alpha-adrenergic agonist, primarily targeting the physical obstruction of the nasal passages. Phenylephrine acts to shrink the swollen tissue in the nose. The medication's key differentiating factor is its oral solution dosage form, a liquid preparation marketed specifically as infant drops, making it the appropriate and convenient dosage form for oral administration to pediatric patients.


How Does the Combination Work?

The medication provides relief through a dual-action principle that targets two different sources of discomfort. The Brompheniramine component works by blocking the effects of histamine, which helps to reduce symptoms such as a runny nose and watery eyes. Simultaneously, the Phenylephrine Hydrochloride component works by causing vasoconstriction in the nasal lining, which helps to shrink the swollen nasal mucosa and relieve congestion. This integrated approach ensures comprehensive cold and allergy relief by managing both the excessive fluid discharge and the physical obstruction that lead to a stuffy nose.

Regulatory References

  1. MedlinePlus

What side effects are possible with Dimetapp Infant?

Possible Side Effects and Safety Information

The safety profile for this fixed-dose combination of Brompheniramine maleate and Phenylephrine hydrochloride is established through regulatory classifications that organize documented adverse reactions by frequency and affected body system.

Documented Adverse Reactions

The most common side effects listed in regulatory labeling primarily involve the Nervous System and Gastrointestinal System. These include drowsiness, headache, dry mouth, dry nose, and constipation. Dizziness and insomnia are also documented as common effects. In certain populations, particularly pediatric patients, a paradoxical reaction of excitability or nervousness may be observed.

Safety Restrictions and Serious Reactions

The official labeling includes specific safety considerations that define the constraints for use. A major restriction concerns the concurrent administration with or within two weeks of stopping a Monoamine Oxidase Inhibitor (MAOI), due to the documented risk of a serious adverse reaction. The product may cause Central Nervous System (CNS) depression, which can impair mental and physical abilities.

Safety statements also address specific high-risk conditions, such as existing heart disease, high blood pressure, thyroid disease, diabetes, or glaucoma, where consultation is necessary. Furthermore, safety considerations for older adults highlight the increased potential for certain CNS effects and subsequent risk of falls. The appearance of severe nervousness, persistent dizziness, or a rash are documented as signals requiring attention.

Overdose and Emergency Response

Overdose and When to Seek Help

Official regulatory information for products historically marketed as "Dimetapp Infant" emphasizes the serious, life-threatening nature of potential overdose, particularly in young children, which led to significant safety advisories.


Documented Overdose Profile

Component Regulatory Findings and Risks
Documented Manifestations Symptoms may include central nervous system stimulation (e.g., increased heart rate, blood pressure), followed by depression (severe drowsiness, slow heart rate). Other signs include seizures, impaired coordination, psychotic behavior, and ultimately, coma or death.
High-Risk Population Children under 2 years of age are the most vulnerable population. Regulatory warnings explicitly state that the use of these ingredients in children under this age is associated with the risk of serious and possibly fatal overdose and adverse events.
Overdose Factors The risk of accidental overdose is significantly heightened by misuse, medication errors (including using multiple products containing the same ingredient), and the use of incorrect dosing devices.

Required Emergency Actions

Immediate medical help must be sought right away if there is any suspicion of accidental ingestion or if a child has been given more than the recommended amount. The latency of severe symptoms means that the absence of early signs does not indicate safety. Healthcare providers should be contacted immediately if any problems related to the use of the product are suspected or observed. The focus of the regulatory guidance is on prompt intervention due to the potential for a rapidly escalating, serious clinical outcome.

Therapeutic Uses of Dimetapp Infant

What Dimetapp Infant Treats: Main Uses and Benefits

Dimetapp Infant is formulated to provide temporary relief of symptoms associated with the common cold and upper respiratory allergies in certain pediatric age groups. This over-the-counter preparation is intended to help manage several related symptoms to allow for improved comfort during illness.

Quick Facts on Use

  • Relieves Nasal Congestion: Helps address the symptom of a stuffy nose and assists in restoring freer breathing through the nasal passages.
  • Addresses Allergic Symptoms: May reduce the incidence of a runny nose, sneezing, and itching of the nose, throat, or itchy, watery eyes associated with hay fever or allergies.
  • Manages Cough: Can be used to temporarily calm coughing to allow for better rest.

This medication is indicated for the temporary relief of these specific symptoms and should only be used as directed by a healthcare professional.

Regulatory References

  1. NIH MedlinePlus guidance

Eligibility and Restrictions for Use

Dimetapp Infant (which may contain active ingredients such as an antihistamine and a decongestant) is specifically formulated for use in infants and children, but strict age and health guidelines must be followed. It is essential to consult a healthcare provider before administering this product to ensure proper dosage and suitability.


Who Can Use Dimetapp Infant?

  • Infants and Children within the age range specified on the product packaging. Depending on the formulation, this may include children 6 months and older for temporary relief of cold and allergy symptoms, but never for children under 2 years of age without explicit medical advice.
  • Individuals seeking temporary relief of symptoms such as blocked nose, runny nose, sneezing, and itchy/watery eyes associated with the common cold or hay fever.

Who Cannot Use Dimetapp Infant?

Use of Dimetapp Infant is typically contraindicated in several groups due to the risk of serious side effects:

  • Infants under 6 months of age (or under 2 years, depending on the specific product formulation and region), as cough and cold products have not been shown to be safe or effective in very young children.
  • Patients with known hypersensitivity or allergy to any of the active ingredients (e.g., brompheniramine maleate, phenylephrine hydrochloride).
  • Individuals taking or who have recently taken (within the last 14 days) a Monoamine Oxidase Inhibitor (MAOI), a class of medication for depression.
  • Patients with certain pre-existing medical conditions, including severe high blood pressure (hypertension), narrow-angle glaucoma, severe coronary artery disease, symptomatic prostatic hypertrophy, or difficulty urinating.

What should I know about interactions with other medicines?

Interactions with other medicines and products

The interaction profile of Dimetapp Infant (Brompheniramine maleate and Phenylephrine Hydrochloride) is characterized by specific pharmacodynamic and co-administration restrictions documented in regulatory labeling. This information strictly details the officially acknowledged interaction patterns.

Formal Regulatory Restrictions

Co-administration with Monoamine Oxidase Inhibitors (MAOIs) is formally contraindicated. This includes substances like Isocarboxazid, Phenelzine, and Selegiline. A mandatory timing-based rule requires that the medicine must not be used within 14 days of stopping therapy with an MAOI. This constraint addresses the risk of dangerous pressor effects and intensified antihistamine action.

Pharmacodynamic Interaction Patterns

The medicine is documented to interact with other substances that affect the central nervous system. Co-administration with Central Nervous System (CNS) Depressants, such as sedatives, tranquilizers, hypnotics, and opioid medicines, is documented to result in additive CNS depression. This pharmacodynamic enhancement is related to the antihistamine component.

Similarly, use with other Sympathomimetics is restricted due to the potential for augmented adrenergic effects, increasing the risk of adverse cardiovascular outcomes. Official labeling also requires the formal avoidance of alcohol due to the documented risk of increasing the sedative effects of the medicine.

Mechanism of Action

The compound engages a coordinated, dual-mechanism approach that modulates two separate physiological systems: the histamine-mediated secretory pathway and the sympathomimetic vascular tone pathway.

Modulation of the Histamine H1 Signaling Pathway

This domain is driven by Brompheniramine, which acts as a competitive antagonist at the peripheral Histamine H1 receptors. By blocking histamine from activating these receptors, the compound suppresses the molecular signal that modulates capillary permeability and sensory nerve signaling. This mechanistic cascade results in reduced histamine-induced increase in capillary permeability, influencing the transvascular movement of fluid and the subsequent local tissue fluid content.

Targeted Activation of Nasal alpha1-Adrenergic Receptors

The second domain engages Phenylephrine, a direct-acting agonist on alpha1-adrenergic receptors located on the vascular smooth muscle in the nasal mucosa. Activation of this receptor triggers a signaling cascade that forces the contraction of these blood vessels (vasoconstriction). This mechanism results in the physical reduction of the volume of the nasal lining due to decreased vascular diameter.

Dosage and Administration Information

How to Use Dimetapp Infant

Dimetapp Infant is a combination oral solution intended for oral administration only. Its usage is strictly governed by precise, age-specific dosing volumes and frequencies. The medicine must be measured using the calibrated dropper or measuring device supplied with the product to ensure accurate delivery of the dose.


Official Dosing and Frequency

Administration follows an intermittent, as-needed schedule, with intervals of at least six hours between doses. The total administration is constrained to not exceed four doses in any 24-hour period.

Dosing is calculated based on the infant's age group, with volumes specified in milliliters (mL):

Age Group Recommended Dose (mL) Frequency Constraint
1–3 months 0.75 to 1.0 mL Every 6-8 hours Requires doctor/pharmacist advice
4–6 months 1.0 to 1.25 mL Every 6-8 hours Requires doctor/pharmacist advice
7–11 months 1.25 to 1.50 mL Every 6-8 hours Use as directed
12–24 months 1.50 to 2.0 mL Every 6-8 hours Use as directed

Administration Requirements

The use of this medication in the youngest infants (e.g., those under six months of age) should occur only upon the advice of a doctor or pharmacist. The medicine does not require dilution and may be administered with food, water, or milk to aid in patient tolerance. The entire protocol is structured to deliver a specific, age-dependent volume while strictly observing the maximum daily dose limit. If symptoms do not improve within seven days, consultation with a healthcare professional is necessary, as the product is intended for short-term use.

Recent Clinical Evidence

Overview of Regulatory and Efficacy Data

Clinical evidence regarding the safety and effectiveness of Dimetapp Infant Drops—a former over-the-counter (OTC) formulation typically containing a combination of an antihistamine and a decongestant—has been a subject of significant regulatory review. The general consensus from systematic reviews and regulatory bodies is that OTC cough and cold medications are not proven to be safe or effective for young children, specifically those under two years of age.


Safety Concerns in Infants

Safety data collected from emergency departments and public health reports documented instances of severe adverse events, including fatalities, associated with the use of multi-symptom cold medications in infants and toddlers. These risks were frequently linked to accidental overdose and the potential for serious side effects from ingredients like decongestants (e.g., phenylephrine or pseudoephedrine) and antihistamines (e.g., brompheniramine).


Discontinuation and Current Recommendations

In response to mounting safety concerns and the limited evidence of clinical benefit in the youngest age group, manufacturers voluntarily removed infant cough and cold products from the market starting in 2007. This action included the discontinuation of Dimetapp Infant Drops and similar formulations. Major regulatory agencies subsequently advised that these products should not be administered to children under two years of age and recommended caution for use in children under six years.

Studies on antihistamine-decongestant combinations in preschool children have frequently found that they are equivalent to placebo in providing temporary relief of upper respiratory symptoms, but they do carry the risk of adverse effects, such as increased sedation.

Frequently Asked Questions (FAQ)

Common questions about Dimetapp Infant (FAQ)

Q: What is the difference between Dimetapp Infant and Children's Dimetapp?

Official regulatory labels indicate that 'Dimetapp Infant' and 'Children's Dimetapp' are distinct products primarily intended for different age groups. They often vary in the concentration of active ingredients and may contain different components. For example, some Children's formulations include a cough suppressant, which is generally not present in the Infant Drops product.

Q: How long does the effect of Dimetapp Infant last?

The expected duration of the medicine's effect is generally reflected by the maximum time interval between doses stated in regulatory labeling. Official administration instructions typically state that a dose may be repeated every 6 to 8 hours as needed.

Q: Can Dimetapp Infant be used for symptoms other than just cold and allergies?

Official regulatory labeling restricts the product's use to the temporary relief of symptoms associated with the common cold, hay fever, or other upper respiratory allergies. These indications include signs such as runny nose, sneezing, itchy/watery eyes, and nasal congestion. It is not generally intended for conditions outside these established uses.

Q: Is it okay to use Dimetapp Infant if the infant is also taking prescription medication for asthma?

Regulatory documents state that consultation with a doctor or pharmacist is required before use if the infant has certain health problems, including lung or breathing disease such as asthma or a chronic cough. This is part of the established warnings for the product.

Q: Can I mix Dimetapp Infant with milk or juice?

According to official administration guidelines, the medicine may be given with food, water, or milk to aid in patient tolerance. Official guidelines primarily detail these substances for co-administration.

Q: Have there been recent studies about the safety profile of Dimetapp Infant?

The regulatory status of cold and cough products intended for infants has been subject to reviews and studies. These regulatory actions have led to the market removal of certain formulations intended for very young children (under two years old) due to documented concerns about safety and limited effectiveness in that age group.

Q: What is the maximum number of days Dimetapp Infant is intended to be used?

Official guidance states that consultation with a healthcare professional is necessary if symptoms do not improve within seven days, which defines the short-term intended use of the product. The medicine is not intended for prolonged or continuous use.

Q: What is the official recommendation regarding using Dimetapp Infant with other cough or cold products?

Regulatory warnings state that this medicine should not be used with any other product that contains an antihistamine, decongestant, or cough suppressant. Official guidance states that use with other products containing similar active ingredients must only occur if specifically directed by a healthcare professional.

Q: What are the signs of a serious allergic reaction to Dimetapp Infant?

Serious allergic reactions are rare, but regulatory information lists signs such as rash, itching, or swelling (particularly of the face, tongue, or throat). Severe dizziness or trouble breathing are also signals that require attention from a healthcare provider.

Q: Is it true that this medicine can make breathing issues worse for infants with certain lung conditions?

Regulatory warnings caution against use in patients with certain pre-existing conditions, including lung disease or persistent cough. Such conditions may require consultation before use due to the potential for complications.

Q: Can infants with kidney or liver conditions use Dimetapp Infant?

Official drug interaction guides and warnings require caution and medical consultation for patients who have pre-existing conditions affecting the liver or kidneys. This consultation ensures the suitability of the product.

Q: Are there any long-term effects associated with using Dimetapp Infant?

Since the product is intended only for short-term use, official regulatory documents do not contain specific information regarding long-term effects. The medicine is not authorized for continuous or prolonged administration.

Q: What specific types of foods or drinks should be avoided while using Dimetapp Infant?

Official regulatory warnings describe the avoidance of alcohol while the medicine is in use. This is due to the potential for additive Central Nervous System (CNS) effects from the antihistamine component.

Q: What happens if Dimetapp Infant is used close to bedtime?

The antihistamine component, Brompheniramine, may cause drowsiness, which is a documented side effect. When administered near bedtime, parents should monitor the infant for this effect, although the medicine is typically dosed every 6 to 8 hours.

Q: Is Dimetapp Infant suitable for infants who are premature or very young?

Regulatory guidance advises against the use of cold and cough products in very young children, often warning against use in those under 2 years of age without explicit medical advice. Information regarding premature infants is not typically detailed on standard over-the-counter product labels.

Q: What are the age or weight restrictions described for using Dimetapp Infant?

The primary restrictions are based on the infant’s age, which dictates the appropriate dosing volume as detailed in official charts. While age is the main restriction, some regional product labeling may also provide corresponding weight-based guidelines for administration.

Q: Is Dimetapp Infant available without a prescription?

In most jurisdictions, Dimetapp Infant is officially classified by the government as an Over-the-Counter (OTC) medicine. This classification means it is authorized for purchase without the need for a prescription.

Q: Does Dimetapp Infant contain any sugar or alcohol?

Official drug labels list all inactive ingredients, which typically include sweeteners such as sucralose or sorbitol solution to improve taste. For the common Infant Drops liquid, most regulatory labels indicate the product does not contain alcohol.

Q: Is there a known risk of dependence or withdrawal from Dimetapp Infant?

Regulatory documents generally do not list dependence or withdrawal as typical risks associated with the short-term use of this specific combination product. However, regulatory bodies caution about the potential for misuse associated with various cold and cough formulations.

Q: What is the official purpose of the dye or coloring used in Dimetapp Infant?

Official labeling lists specific dyes under inactive ingredients, such as FD&C Blue No. 1 or Red No. 40. The stated purpose of these ingredients is typically to provide color, which assists in product identification and distinction from other medicines.

Q: Are there any specific safety warnings for infants with heart conditions regarding Dimetapp Infant?

Regulatory documents require consultation before use if the infant has existing heart disease or high blood pressure. This is a necessary precaution because the decongestant component, Phenylephrine, may affect the cardiovascular system.

Q: Is there a difference in efficacy between the different flavors of Dimetapp Infant?

Regulatory agencies review products based on their active ingredients. A change in flavor is categorized as a difference in the inactive ingredients and is therefore not considered to affect the efficacy of the active components.

Q: What are the inactive ingredients in Dimetapp Infant and do they have any effect?

Official labels list all inactive ingredients, which include components like flavors, colors, and preservatives. While these ingredients do not contribute to the medicine's therapeutic effect, they can be important to note as they may cause reactions in individuals with specific sensitivities or allergies.

Q: Why is the dosage measured differently for infants compared to older children?

Official dosing is scaled according to age and sometimes weight to ensure appropriate levels of medication are administered. This scaling accounts for physiological differences in body size, drug metabolism, and sensitivity among younger patients.

Q: Are there different versions or formulas of Dimetapp Infant on the market?

Regulatory documents confirm that different formulations exist across regions. These can include versions such as 'Infant Drops' and 'Colour Free Infant Drops,' which contain the same active ingredients but vary in their inactive components like dyes.

Q: What regulatory body approved Dimetapp Infant for use in infants?

The product is regulated and approved by the government body responsible for medication oversight in each specific region. Examples of such bodies include the Therapeutic Goods Administration (TGA) in Australia or the Food and Drug Administration (FDA) in the United States.

Q: How does Dimetapp Infant affect a breastfed infant if the mother is taking it?

Regulatory warnings advise that the product may pass into breast milk and could potentially have undesirable effects on a nursing infant. Official guidance states that consultation with a healthcare professional is necessary before use while breastfeeding.

Q: Is Dimetapp Infant intended for use for all types of infant coughs or only certain ones?

The specific formulation of Dimetapp Infant (Brompheniramine/Phenylephrine) is primarily indicated by regulatory bodies for symptoms like nasal congestion and allergy symptoms. The official label for this specific infant formulation does not typically list cough suppression as an approved indication.

Q: Does Dimetapp Infant have a specific classification regarding controlled substances?

The active ingredients (Brompheniramine and Phenylephrine) in this formulation are generally not classified as controlled substances by the US Drug Enforcement Administration (DEA) or similar national agencies in other regions.

Q: Does the medicine come with a specific measuring tool?

Administration guidelines state that the medicine must be measured using the calibrated dropper or measuring device supplied with the product. This ensures the delivery of the accurate dose required by regulatory guidelines.

How should Dimetapp Infant be stored and disposed of?

Storage and Handling Requirements

Official regulatory documents require that Dimetapp Infant be stored in a cool, dry place where the temperature stays below 25 C or within the range of 20 C to 25 C (68 F to 77 F). The product must be kept in the container it came in and maintained tightly closed.

To ensure stability, the liquid must be protected from excess heat and moisture; therefore, it should not be stored in a bathroom, left in a car, or placed on a window sill.

Child Safety and Disposal

All medication, including Dimetapp Infant, must be stored out of the sight and reach of children, and the safety cap must be securely locked. After the expiry date has passed, any unused or expired Dimetapp Infant must be returned to a pharmacist for safe and official disposal.

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

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