Ed A-Hist 4-10/5ml Liquid
It is used to treat nose stuffiness.It is used to ease allergy signs.
Drug Class
Antihistamine and Decongestant Combination
Pharmacologic Class
H1-antagonist (first-generation) and Alpha-1 adrenergic agonist
Pregnancy Category
Category C
FDA Approved
Jan 1970
DEA Schedule
Not Controlled
Overview
What is this medicine?
This medicine is a combination of an antihistamine and a decongestant. The antihistamine (chlorpheniramine) helps relieve sneezing, runny nose, and watery eyes caused by allergies or colds. The decongestant (phenylephrine) helps clear up stuffy nose by shrinking blood vessels in the nasal passages.
How to Use This Medicine
Taking Your Medication Correctly
To get the most benefit from your medication, it's essential to follow your doctor's instructions carefully. Read all the information provided with your medication and follow the instructions closely. You can take this medication with or without food. If it causes stomach upset, taking it with food may help. When measuring liquid doses, use the measuring device that comes with the medication. If one is not provided, ask your pharmacist for a suitable measuring device.
Storing and Disposing of Your Medication
Store your medication at room temperature in a dry place, avoiding the bathroom. Keep all medications in a safe location, out of the reach of children and pets. Dispose of unused or expired medications properly. Do not flush them down the toilet or pour them down the drain unless instructed to do so. If you're unsure about the best way to dispose of your medication, consult your pharmacist. You may also want to check if there are drug take-back programs in your area.
What to Do If You Miss a Dose
If you take this medication regularly, take the missed dose as soon as you remember. However, if it's close to the time for your next dose, skip the missed dose and resume your regular schedule. Do not take two doses at the same time or take extra doses. If you take this medication as needed, do not take it more frequently than directed by your doctor.
To get the most benefit from your medication, it's essential to follow your doctor's instructions carefully. Read all the information provided with your medication and follow the instructions closely. You can take this medication with or without food. If it causes stomach upset, taking it with food may help. When measuring liquid doses, use the measuring device that comes with the medication. If one is not provided, ask your pharmacist for a suitable measuring device.
Storing and Disposing of Your Medication
Store your medication at room temperature in a dry place, avoiding the bathroom. Keep all medications in a safe location, out of the reach of children and pets. Dispose of unused or expired medications properly. Do not flush them down the toilet or pour them down the drain unless instructed to do so. If you're unsure about the best way to dispose of your medication, consult your pharmacist. You may also want to check if there are drug take-back programs in your area.
What to Do If You Miss a Dose
If you take this medication regularly, take the missed dose as soon as you remember. However, if it's close to the time for your next dose, skip the missed dose and resume your regular schedule. Do not take two doses at the same time or take extra doses. If you take this medication as needed, do not take it more frequently than directed by your doctor.
Lifestyle & Tips
- Avoid driving or operating heavy machinery until you know how this medication affects you, as it can cause drowsiness.
- Avoid alcohol and other sedating medications, as they can increase drowsiness.
- Stay hydrated to help with dry mouth.
- Do not exceed the recommended dose, especially in children, as overdose can be serious.
Available Forms & Alternatives
Dosing & Administration
Adult Dosing
Standard Dose:
5-10 mL (Chlorpheniramine 4-8 mg / Phenylephrine 10-20 mg) orally every 4-6 hours as needed, not to exceed 6 doses in 24 hours.
Dose Range:
5 - 10 mg
Condition-Specific Dosing:
maxDailyDose:
60 mL (Chlorpheniramine 48 mg / Phenylephrine 120 mg)
Pediatric Dosing
Neonatal:
Not established
Infant:
Not established
Child:
6 to under 12 years: 2.5-5 mL (Chlorpheniramine 2-4 mg / Phenylephrine 5-10 mg) orally every 4-6 hours as needed, not to exceed 6 doses in 24 hours. Not recommended for children under 6 years without physician consultation.
Adolescent:
12 years and older: Same as adult dosing.
Dose Adjustments
Renal Impairment:
Mild:
No specific adjustment recommended, use with caution.
Moderate:
Use with caution, consider reduced dose or extended interval due to potential for increased side effects from chlorpheniramine.
Severe:
Use with caution, consider reduced dose or extended interval due to potential for increased side effects from chlorpheniramine.
Dialysis:
Not well studied; use with caution. Chlorpheniramine is dialyzable to some extent.
Hepatic Impairment:
Mild:
No specific adjustment recommended, use with caution.
Moderate:
Use with caution, consider reduced dose or extended interval due to impaired metabolism of both components.
Severe:
Use with caution, consider reduced dose or extended interval due to impaired metabolism of both components.
Pharmacology
Mechanism of Action
Chlorpheniramine is a first-generation antihistamine that competitively blocks H1 receptors, thereby preventing the effects of histamine (e.g., vasodilation, increased capillary permeability, pruritus, bronchoconstriction). It also possesses anticholinergic properties. Phenylephrine is a direct-acting sympathomimetic amine that acts predominantly on alpha-1 adrenergic receptors in the respiratory tract mucosa, causing vasoconstriction, which reduces swelling and congestion.
Pharmacokinetics
Absorption:
Bioavailability:
Chlorpheniramine: ~25-45% (variable due to first-pass metabolism); Phenylephrine: ~38% (variable due to extensive first-pass metabolism)
Tmax:
Chlorpheniramine: 2.5-6 hours; Phenylephrine: 0.5-2 hours (oral)
FoodEffect:
Food may delay absorption but generally does not significantly affect extent of absorption.
Distribution:
Vd:
Chlorpheniramine: 3.2 L/kg; Phenylephrine: Not readily available for oral form, but widely distributed.
ProteinBinding:
Chlorpheniramine: 69-72%; Phenylephrine: Not extensively protein bound.
CnssPenetration:
Chlorpheniramine: Yes (contributes to sedation); Phenylephrine: Limited (does not readily cross BBB).
Elimination:
HalfLife:
Chlorpheniramine: 12-43 hours (highly variable); Phenylephrine: 2-3 hours
Clearance:
Not readily available for combination
ExcretionRoute:
Renal (primarily)
Unchanged:
Chlorpheniramine: ~34% (variable); Phenylephrine: ~2.6% (oral)
Pharmacodynamics
OnsetOfAction:
Chlorpheniramine: 15-60 minutes; Phenylephrine: 15-30 minutes
PeakEffect:
Chlorpheniramine: 3-9 hours; Phenylephrine: 1-2 hours
DurationOfAction:
Chlorpheniramine: 4-6 hours; Phenylephrine: 4-6 hours
Confidence:
Medium
Safety & Warnings
Side Effects
Urgent Side Effects: Seek Medical Attention Immediately
If you experience any of the following symptoms, call your doctor or seek medical help right away, as they may be signs of a severe and potentially life-threatening reaction:
- Signs of an allergic reaction, such as rash, hives, itching, red, swollen, blistered, or peeling skin (with or without fever), wheezing, tightness in the chest or throat, trouble breathing, swallowing, or talking, unusual hoarseness, or swelling of the mouth, face, lips, tongue, or throat.
Other Possible Side Effects
While many people taking this medication may not experience side effects or may only have mild ones, it's essential to be aware of the following:
- Feeling dizzy or sleepy
- Feeling nervous and excitable
- Trouble sleeping
If any of these side effects or any others bother you or do not go away, contact your doctor for advice.
Reporting Side Effects
This list does not include all possible side effects. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
If you experience any of the following symptoms, call your doctor or seek medical help right away, as they may be signs of a severe and potentially life-threatening reaction:
- Signs of an allergic reaction, such as rash, hives, itching, red, swollen, blistered, or peeling skin (with or without fever), wheezing, tightness in the chest or throat, trouble breathing, swallowing, or talking, unusual hoarseness, or swelling of the mouth, face, lips, tongue, or throat.
Other Possible Side Effects
While many people taking this medication may not experience side effects or may only have mild ones, it's essential to be aware of the following:
- Feeling dizzy or sleepy
- Feeling nervous and excitable
- Trouble sleeping
If any of these side effects or any others bother you or do not go away, contact your doctor for advice.
Reporting Side Effects
This list does not include all possible side effects. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- Severe dizziness or drowsiness
- Fast, pounding, or irregular heartbeat
- Significant increase in blood pressure
- Difficulty urinating
- Severe nervousness, restlessness, or tremors
- Hallucinations or confusion
- Signs of an allergic reaction (rash, itching, swelling, severe dizziness, trouble breathing)
- Worsening of symptoms or new symptoms developing
Before Using This Medicine
Before taking this medication, it is essential to inform your doctor about the following:
Any allergies you have, including allergies to this drug, its components, or other substances. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
If you have taken certain medications for depression or Parkinson's disease within the last 14 days, such as isocarboxazid, phenelzine, tranylcypromine, selegiline, or rasagiline, as this may increase the risk of very high blood pressure.
If you are currently taking linezolid or methylene blue, as these medications can interact with this drug.
All prescription and over-the-counter medications, natural products, and vitamins you are taking, as well as any health problems you have. This is not an exhaustive list of potential interactions, and it is crucial to discuss all your medications and health issues with your doctor and pharmacist to ensure safe use.
* Do not initiate, discontinue, or modify the dose of any medication without first consulting your doctor to verify that it is safe to do so in conjunction with this drug.
Any allergies you have, including allergies to this drug, its components, or other substances. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
If you have taken certain medications for depression or Parkinson's disease within the last 14 days, such as isocarboxazid, phenelzine, tranylcypromine, selegiline, or rasagiline, as this may increase the risk of very high blood pressure.
If you are currently taking linezolid or methylene blue, as these medications can interact with this drug.
All prescription and over-the-counter medications, natural products, and vitamins you are taking, as well as any health problems you have. This is not an exhaustive list of potential interactions, and it is crucial to discuss all your medications and health issues with your doctor and pharmacist to ensure safe use.
* Do not initiate, discontinue, or modify the dose of any medication without first consulting your doctor to verify that it is safe to do so in conjunction with this drug.
Precautions & Cautions
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication.
To minimize the risk of severe side effects, adhere strictly to the dosage instructions provided by your doctor. Do not exceed the recommended dose, as this may increase your likelihood of experiencing adverse effects. Additionally, do not take this medication for a longer duration than prescribed by your doctor.
Until you are familiar with how this medication affects you, exercise caution when engaging in activities that require alertness, such as driving. It is also recommended that you avoid consuming alcohol while taking this drug.
Before using marijuana, other forms of cannabis, or any prescription or over-the-counter (OTC) medications that may cause drowsiness, consult with your doctor to discuss potential interactions.
If you are considering giving this medication to a child, it is crucial to consult with the doctor first, as different brands may have varying dosage recommendations for children. When administering this drug to a child, do so with caution, as children may have a higher risk of experiencing excitability. Furthermore, do not use this medication as a means to induce sleep in children; instead, consult with the doctor for guidance.
If you are pregnant, planning to become pregnant, or are breastfeeding, inform your doctor, as it is necessary to discuss the potential benefits and risks of this medication to both you and the baby.
To minimize the risk of severe side effects, adhere strictly to the dosage instructions provided by your doctor. Do not exceed the recommended dose, as this may increase your likelihood of experiencing adverse effects. Additionally, do not take this medication for a longer duration than prescribed by your doctor.
Until you are familiar with how this medication affects you, exercise caution when engaging in activities that require alertness, such as driving. It is also recommended that you avoid consuming alcohol while taking this drug.
Before using marijuana, other forms of cannabis, or any prescription or over-the-counter (OTC) medications that may cause drowsiness, consult with your doctor to discuss potential interactions.
If you are considering giving this medication to a child, it is crucial to consult with the doctor first, as different brands may have varying dosage recommendations for children. When administering this drug to a child, do so with caution, as children may have a higher risk of experiencing excitability. Furthermore, do not use this medication as a means to induce sleep in children; instead, consult with the doctor for guidance.
If you are pregnant, planning to become pregnant, or are breastfeeding, inform your doctor, as it is necessary to discuss the potential benefits and risks of this medication to both you and the baby.
Overdose Information
Overdose Symptoms:
- Severe drowsiness or sedation (especially in adults)
- Excitement, agitation, hallucinations, seizures (especially in children)
- Dilated pupils
- Flushing
- Dry mouth, fever
- Urinary retention
- Rapid or irregular heartbeat
- High blood pressure (initially), followed by low blood pressure
- Coma
What to Do:
Seek immediate medical attention or call Poison Control (1-800-222-1222). Management is supportive and symptomatic, including gastric lavage, activated charcoal, and treatment of specific symptoms (e.g., benzodiazepines for seizures, IV fluids for hypotension).
Drug Interactions
Contraindicated Interactions
- Monoamine Oxidase Inhibitors (MAOIs) (concurrent use or within 14 days of MAOI discontinuation) - risk of hypertensive crisis with phenylephrine, prolonged and intensified anticholinergic effects with chlorpheniramine.
Major Interactions
- Other sympathomimetics (e.g., pseudoephedrine, ephedrine, stimulants) - increased risk of cardiovascular effects (hypertension, tachycardia).
- Beta-blockers (non-selective) - may increase pressor response to phenylephrine.
- Tricyclic antidepressants (TCAs) - may potentiate cardiovascular effects of phenylephrine.
- CNS depressants (e.g., alcohol, sedatives, hypnotics, anxiolytics, opioids) - additive CNS depression (drowsiness, dizziness).
Moderate Interactions
- Anticholinergic drugs (e.g., atropine, some antipsychotics, TCAs) - additive anticholinergic effects (dry mouth, blurred vision, urinary retention, constipation).
- Digoxin - phenylephrine may increase risk of arrhythmias.
- Alpha-adrenergic blocking agents (e.g., prazosin) - may reduce decongestant effect of phenylephrine.
Minor Interactions
- Antacids - may increase absorption of phenylephrine.
- Kaolin/Pectin - may decrease absorption of chlorpheniramine.
Monitoring
Symptom Monitoring
- Effectiveness of symptom relief (nasal congestion, sneezing, runny nose)
- Drowsiness or sedation
- Dizziness
- Dry mouth, blurred vision, urinary retention (anticholinergic effects)
- Nervousness, restlessness, insomnia (stimulant effects of phenylephrine)
- Heart rate and blood pressure (especially in patients with pre-existing cardiovascular conditions)
- Signs of allergic reaction (rash, itching, swelling)
Special Patient Groups
Pregnancy
Use with caution during pregnancy, especially in the first trimester. Chlorpheniramine is generally considered low risk, but phenylephrine is a vasoconstrictor and its use, particularly in the first trimester or in patients with pre-existing hypertension, should be avoided unless clearly necessary. Category C.
Trimester-Specific Risks:
First Trimester:
Phenylephrine: Potential for vasoconstriction affecting uterine blood flow; generally avoided. Chlorpheniramine: Limited data, generally considered low risk.
Second Trimester:
Generally considered safer than first trimester, but still use with caution.
Third Trimester:
Avoid use near term due to potential for premature labor or adverse effects on the fetus (e.g., vasoconstriction).
Lactation
Use with caution. Both chlorpheniramine and phenylephrine are excreted into breast milk. Chlorpheniramine can cause drowsiness in the infant and may decrease milk supply due to its anticholinergic effects. Phenylephrine may also reduce milk supply. L3 (Moderately Safe).
Infant Risk:
Drowsiness, irritability, or paradoxical excitation in infant; potential for decreased milk supply.
Pediatric Use
Not recommended for children under 6 years of age without specific physician guidance due to potential for serious side effects, including overdose. Use with extreme caution in children, adhering strictly to weight-based or age-based dosing. First-generation antihistamines can cause paradoxical excitation in young children.
Geriatric Use
Elderly patients are more susceptible to the anticholinergic effects of chlorpheniramine (e.g., sedation, confusion, dry mouth, urinary retention, constipation) and the cardiovascular effects of phenylephrine (e.g., hypertension, tachycardia). Use with caution, starting with lower doses and monitoring closely.
Clinical Information
Clinical Pearls
- This combination is effective for multi-symptom cold and allergy relief, but its sedating effects should be communicated to patients.
- Advise patients to check other OTC medications for similar active ingredients to avoid accidental overdose.
- Patients with underlying conditions such as hypertension, heart disease, glaucoma, prostate enlargement, or thyroid disease should consult a physician before use due to phenylephrine and anticholinergic effects.
- The liquid formulation allows for flexible dosing, but accurate measurement is crucial, especially in children.
Alternative Therapies
- Single-ingredient antihistamines (e.g., loratadine, cetirizine for non-sedating options; diphenhydramine for sedating)
- Single-ingredient decongestants (e.g., pseudoephedrine, oxymetazoline nasal spray)
- Nasal saline rinses
- Corticosteroid nasal sprays (for allergies)
Cost & Coverage
Average Cost:
Varies widely, typically $10-$30 per 120-240 mL bottle
Generic Available:
Yes
Insurance Coverage:
Often not covered by prescription plans as it's an OTC product, but may be eligible for FSA/HSA.
General Drug Facts
If your symptoms or health issues persist or worsen, it is essential to contact your doctor promptly. To ensure safe and effective treatment, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so it is a good idea to check with your pharmacist for more information. If you have any questions or concerns about this medication, do not hesitate to discuss them with your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek emergency medical attention. When seeking help, be prepared to provide detailed information about the overdose, including the medication taken, the amount, and the time it occurred.