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Medical Disclaimer: This information is for educational purposes only and is not a substitute for professional medical advice.
Brand Name
Ala-hist Ir
Generic Name
Dexbrompheniramine Maleate
Active Ingredient
DexbrompheniramineCategory
Other
Salt Form
Maleate
Variants
1
Different strengths and dosage forms
| Strength | Form | Route | NDC |
|---|---|---|---|
| 2 mg/1 | TABLET | ORAL | 50991-783 |
Detailed information about Ala-hist Ir
This page is for informational purposes only and does not replace medical advice. Before using any prescription or over-the-counter medication for Ala-hist Ir, you must consult a qualified healthcare professional.
Dexbrompheniramine is a potent first-generation antihistamine belonging to the alkylamine class, primarily used for the symptomatic relief of allergic rhinitis and the common cold. It acts as a competitive H1-receptor antagonist to reduce symptoms like sneezing, itching, and watery eyes.
For adults and adolescents aged 12 years and older, the standard dosing for dexbrompheniramine maleate depends on the formulation being used.
When used for the common cold, the medication should only be used for the duration of symptoms. For chronic allergic rhinitis, a healthcare provider may recommend a longer course of treatment, though second-generation antihistamines are often preferred for long-term management to avoid chronic sedation.
Pediatric dosing must be approached with extreme caution. The FDA and manufacturers have specific age-related guidelines to prevent toxicity.
Because the kidneys are responsible for excreting the metabolites of dexbrompheniramine, patients with significant kidney disease (renal impairment) may require lower doses or longer intervals between doses. Accumulation of the drug can lead to increased toxicity and prolonged sedation.
Since the liver metabolizes dexbrompheniramine, individuals with liver cirrhosis or hepatitis should use this medication with caution. Dose reductions may be necessary to prevent the drug from reaching dangerous levels in the blood.
Patients over the age of 65 are more sensitive to the side effects of first-generation antihistamines. The American Geriatrics Society (Beers Criteria) generally recommends avoiding dexbrompheniramine in the elderly due to the high risk of confusion, dizziness, falls, and urinary retention. If use is absolutely necessary, the lowest possible dose should be initiated.
To ensure the safety and efficacy of dexbrompheniramine, patients should adhere to the following guidelines:
If you miss a dose, take it as soon as you remember. If it is almost time for your next scheduled dose, skip the missed dose and return to your regular schedule. Do not 'double up' or take extra medicine to make up for a missed dose, as this significantly increases the risk of overdose.
An overdose of dexbrompheniramine can be life-threatening, especially in children. Signs of overdose include extreme drowsiness, dilated pupils, flushed skin, fever, hallucinations, tremors, and seizures. In severe cases, it can lead to cardiovascular collapse or coma.
If an overdose is suspected, contact your local poison control center or seek emergency medical attention immediately. Treatment usually involves supportive care, such as gastric lavage (stomach pumping) if caught early, and monitoring of vital signs.
> Important: Follow your healthcare provider's dosing instructions. Do not adjust your dose or stop taking this medication without medical guidance, especially if you are using it to manage chronic conditions.
As a first-generation antihistamine, dexbrompheniramine is frequently associated with side effects related to its ability to cross the blood-brain barrier and its interaction with muscarinic receptors.
These side effects occur frequently enough to be noted by many patients but are not universal.
Rarely, patients may experience more unusual reactions that require medical monitoring.
> Warning: Stop taking Dexbrompheniramine and call your doctor immediately if you experience any of these serious symptoms.
Dexbrompheniramine is generally intended for short-term use. Prolonged use (weeks or months) can lead to:
Currently, there are no FDA black box warnings specifically for dexbrompheniramine maleate. However, it is important to note that the FDA has issued strong public health advisories against the use of OTC cough and cold medicines (which often contain dexbrompheniramine) in children under the age of 4, and many manufacturers have voluntarily updated their labels to exclude children under 6.
Report any unusual symptoms or persistent side effects to your healthcare provider. Monitoring is essential to ensure the benefits of the medication outweigh the risks of these side effects.
Dexbrompheniramine is a potent medication that affects the central nervous system (CNS) and the autonomic nervous system. Patients must be aware that the primary safety concern is its sedative effect. This medication can significantly impair mental alertness and physical coordination. Because it remains in the system for a long time (up to 30 hours), these effects may persist well into the day after a dose is taken.
There are no FDA-mandated black box warnings for dexbrompheniramine at this time. It is considered safe and effective when used exactly as directed by a healthcare professional or according to the 'Drug Facts' label on over-the-counter products.
Dexbrompheniramine is a CNS depressant. Using it alongside other substances that slow down brain activity—such as alcohol, benzodiazepines (anti-anxiety meds), or opioid pain medications—can lead to dangerous levels of respiratory depression, extreme lethargy, and even coma.
Patients with chronic obstructive pulmonary disease (COPD), asthma, or emphysema should use dexbrompheniramine with extreme caution. The anticholinergic 'drying' effect can thicken mucus in the airways, making it much harder to clear the lungs during an infection or asthma attack, potentially worsening the condition.
This medication can increase intraocular pressure (pressure inside the eye). It is generally contraindicated or requires very close monitoring in patients with narrow-angle glaucoma, as it could trigger an acute glaucoma attack, which is a medical emergency.
Men with an enlarged prostate (benign prostatic hyperplasia) may find that dexbrompheniramine makes it significantly harder to urinate. In some cases, it can cause acute urinary retention, requiring catheterization.
While less common, antihistamines can cause tachycardia (fast heart rate) and palpitations. Patients with a history of heart disease, hypertension (high blood pressure), or ischemic heart disease should consult their cardiologist before use.
For short-term use, extensive lab monitoring is usually not required. However, if a patient is prescribed dexbrompheniramine for longer periods, healthcare providers may monitor:
Do not drive, operate heavy machinery, or engage in hazardous activities until you know how dexbrompheniramine affects you. The impairment caused by first-generation antihistamines has been compared in clinical studies to the impairment caused by alcohol consumption. Even if you do not 'feel' sleepy, your reaction times may be significantly slowed.
Alcohol must be avoided while taking dexbrompheniramine. Alcohol significantly enhances the sedative effects of the drug, increasing the risk of accidents, falls, and severe respiratory depression.
For most people taking dexbrompheniramine for allergies or a cold, the medication can be stopped abruptly without a tapering schedule. However, if you have been taking it daily for an extended period, you may experience 'rebound' symptoms, such as increased nasal congestion or difficulty sleeping, for a few days after stopping.
> Important: Discuss all your medical conditions, especially respiratory or eye problems, with your healthcare provider before starting Dexbrompheniramine.
Certain medications should never be combined with dexbrompheniramine due to the risk of severe, life-threatening reactions.
For each major interaction, the mechanism usually involves either pharmacodynamic synergy (both drugs doing the same thing to the body, like causing sleepiness) or pharmacokinetic interference (one drug changing how the other is absorbed or broken down).
> Important: Tell your doctor about ALL medications, supplements, and herbal products you are taking. A complete medication review is the best way to prevent dangerous drug interactions.
There are several conditions where the risks of dexbrompheniramine far outweigh any potential benefits. In these cases, the medication must never be used.
These are conditions where the medication should only be used if a doctor determines the benefit is essential and can monitor the patient closely.
Patients who have had a bad reaction to Chlorpheniramine (Chlor-Trimeton) or Brompheniramine (Dimetapp) are very likely to have a similar reaction to dexbrompheniramine. These drugs are chemically related, and the body's immune system often recognizes them in the same way. Always inform your pharmacist if you have reacted poorly to any 'cold and allergy' medicine in the past.
> Important: Your healthcare provider will evaluate your complete medical history before prescribing Dexbrompheniramine. Do not assume an over-the-counter medication is safe for you without checking first.
Dexbrompheniramine is generally classified as FDA Pregnancy Category B. This means that animal reproduction studies have failed to demonstrate a risk to the fetus, but there are no adequate and well-controlled studies in pregnant women.
Always consult an obstetrician before using dexbrompheniramine during pregnancy.
Dexbrompheniramine is known to pass into breast milk in small amounts. Because infants are more susceptible to the side effects of antihistamines (such as unusual irritability or drowsiness), use while breastfeeding is generally discouraged. Furthermore, because of its anticholinergic effects, dexbrompheniramine can actually suppress lactation, making it harder for the mother to produce enough milk for the baby.
As noted, dexbrompheniramine is not approved for use in children under 6 years of age by most guidelines. In children who do take it, 'paradoxical excitation' is a common concern. Instead of becoming sleepy, the child may become extremely hyperactive, experience tremors, or have trouble sleeping. Overdose in children is a medical emergency and can lead to hallucinations and death.
According to the Beers Criteria for Potentially Inappropriate Medication Use in Older Adults, dexbrompheniramine is listed as a drug to be avoided. Older adults have a higher 'anticholinergic burden,' meaning their bodies are more sensitive to drugs that block acetylcholine. In this population, dexbrompheniramine significantly increases the risk of:
In patients with a Glomerular Filtration Rate (GFR) below 50 mL/min, the interval between doses should be increased. If the kidneys cannot filter the drug's metabolites, they will build up in the blood, leading to 'antihistamine toxicity,' characterized by extreme lethargy and dry membranes.
Patients with Child-Pugh Class B or C liver disease should be started on the lowest possible dose (e.g., 1 mg instead of 2 mg) and monitored for signs of over-sedation. The liver's ability to clear the drug is the primary factor in determining how long the drug stays active in the body.
> Important: Special populations require individualized medical assessment. Never share your medication with others, especially children or the elderly.
Dexbrompheniramine maleate is a potent H1-receptor antagonist. At the molecular level, it acts as a competitive inhibitor. It binds to the H1 receptors on the surface of effector cells but does not activate them. By 'parking' in the receptor, it prevents histamine from binding. This prevents the activation of phospholipase C and the subsequent increase in intracellular calcium that normally leads to smooth muscle contraction and increased vascular permeability (swelling).
Additionally, dexbrompheniramine has a high affinity for muscarinic acetylcholine receptors. By blocking these receptors, it inhibits the parasympathetic nervous system's 'rest and digest' signals to the glands in the nose and mouth, leading to the clinical 'drying' effect.
The onset of action for dexbrompheniramine is typically 15 to 30 minutes after oral ingestion. The peak antihistamine effect occurs between 3 and 6 hours. While the allergy-blocking effects may last for 8 to 12 hours, the sedative effects can last significantly longer due to the drug's long half-life. Tolerance to the sedative effects may develop after several days of continuous use, but the H1-blocking efficacy generally remains stable.
| Parameter | Value |
|---|---|
| Bioavailability | Approximately 70-80% |
| Protein Binding | 69% to 72% |
| Half-life | 20 to 30 hours |
| Tmax | 2 to 3 hours |
| Metabolism | Hepatic (CYP450 system) |
| Excretion | Renal (primarily as metabolites) |
Dexbrompheniramine is classified as a First-Generation Antihistamine and specifically belongs to the Alkylamine subclass. Other drugs in this subclass include chlorpheniramine and triprolidine. Alkylamines are generally known for causing less sedation than ethanolamines (like diphenhydramine/Benadryl) but still significantly more than second-generation drugs.
Common questions about Ala-hist Ir
Dexbrompheniramine is primarily used to relieve symptoms of the common cold and upper respiratory allergies. It is highly effective at treating a runny nose, sneezing, and itchy or watery eyes caused by hay fever or dust allergies. Because it has drying properties, it is often preferred for 'wet' allergy symptoms compared to some other medications. However, it only treats the symptoms and does not cure the underlying viral infection or allergic condition. Always consult your doctor to ensure it is the right choice for your specific respiratory symptoms.
The most frequent side effect of dexbrompheniramine is significant drowsiness or sedation, which can impair your ability to drive or work. Many patients also experience 'anticholinergic' effects, which include a very dry mouth, blurred vision, and constipation. Dizziness and a feeling of lightheadedness are also common, especially when first starting the medication. In some cases, particularly in children, it may cause the opposite effect, leading to nervousness or trouble sleeping. Most of these side effects are temporary but can be bothersome during daily activities.
No, you should strictly avoid alcohol while taking dexbrompheniramine. Both alcohol and this medication are central nervous system depressants, meaning they slow down brain activity and coordination. When taken together, they can cause extreme sleepiness, dangerously slow breathing, and a significantly increased risk of accidents or falls. Even a small amount of alcohol can interact poorly with the medication because dexbrompheniramine stays in your system for a long time. Always wait until the medication is completely out of your system before consuming alcoholic beverages.
Dexbrompheniramine is classified as Category B, which generally means it is considered relatively safe, but it should only be used if clearly needed. There are no large-scale studies in pregnant humans to guarantee it is 100% risk-free for the developing fetus. It is especially important to avoid using it near the end of the third trimester, as it could cause adverse reactions in the newborn baby. Most healthcare providers suggest using the lowest dose possible for the shortest amount of time. You must discuss the risks and benefits with your obstetrician before taking this or any antihistamine while pregnant.
Dexbrompheniramine typically begins to work within 15 to 30 minutes after you swallow the tablet or liquid. You will likely notice a reduction in sneezing and itching fairly quickly as the medication begins to block histamine receptors. The 'drying' effect on your runny nose usually peaks within 2 to 3 hours of taking the dose. If you are taking a timed-release version, the effects are designed to last for up to 12 hours. If your symptoms do not improve after a few days of use, you should contact your healthcare provider for further evaluation.
Yes, for most people taking dexbrompheniramine for short-term allergy or cold relief, it is safe to stop taking it at any time. There is no physical 'addiction' to the drug, so you will not experience dangerous withdrawal symptoms like you might with some other medications. However, if you have been using it daily for a long time, you might notice a temporary return of your allergy symptoms, sometimes slightly worse than before, for a day or two. This is known as 'rebound' congestion or itching. If you have concerns about stopping, your doctor can provide a plan to transition to a different medication.
If you miss a dose of dexbrompheniramine, you should take it as soon as you remember, unless it is almost time for your next scheduled dose. If you are within a couple of hours of your next dose, simply skip the missed one and continue with your regular timing. Never take two doses at the same time to 'catch up,' as this can lead to an overdose and severe side effects like extreme grogginess or a rapid heartbeat. Keeping your doses spaced out as directed helps maintain a steady level of the medication in your blood. If you frequently forget doses, using a pill reminder app may be helpful.
Weight gain is not a commonly reported side effect of dexbrompheniramine, especially when used for short periods to treat a cold or seasonal allergies. However, some first-generation antihistamines can increase appetite in certain individuals if used for a long time. Additionally, the drowsiness caused by the medication might lead to decreased physical activity, which could indirectly contribute to weight changes over time. If you notice significant or rapid weight gain while taking this medication, you should discuss it with your doctor. Most people find that their weight remains stable during a standard course of treatment.
Dexbrompheniramine can interact with many other drugs, so caution is necessary. It should never be taken with MAO inhibitors, and you must be very careful when combining it with other 'downers' like sleep aids, muscle relaxants, or anxiety medications. Many over-the-counter cold medicines also contain antihistamines, so taking them together could result in a double dose. Always provide your doctor or pharmacist with a full list of your current medications, including vitamins and herbal supplements. They can check for potential interactions that might make the medication dangerous or less effective.
Yes, dexbrompheniramine maleate is available as a generic medication, although it is most commonly found as an ingredient in generic combination products. Generic versions are required by the FDA to have the same active ingredient, strength, and effectiveness as the brand-name versions. Choosing a generic can often save you money while providing the same level of allergy relief. You can find it in various forms, including tablets and liquids, at most pharmacies. Always check the 'Active Ingredients' section of the label to ensure you are getting the correct medication.
Other drugs with the same active ingredient (Dexbrompheniramine)