Zovirax 200mg/5ml Suspension
It is used to treat shingles or certain other herpes infections.It is used to treat chickenpox.It may be given to you for other reasons. Talk with the doctor.
Drug Class
Antiviral
Pharmacologic Class
Synthetic nucleoside analog, DNA polymerase inhibitor
Pregnancy Category
Category B
FDA Approved
Mar 1985
DEA Schedule
Not Controlled
Overview
What is this medicine?
Acyclovir is an antiviral medicine used to treat infections caused by herpes viruses, such as cold sores, genital herpes, chickenpox, and shingles. It works by stopping the virus from growing and spreading in the body, helping to reduce the severity and duration of outbreaks.
How to Use This Medicine
Taking Your Medication Correctly
To get the most benefit from your medication, follow your doctor's instructions carefully. Read all the information provided with your prescription and follow the instructions closely. You can take this medication with or without food, but if it causes stomach upset, take it with food to help minimize this side effect.
Before taking a liquid dose, shake the bottle well. To ensure accurate dosing, use the measuring device that comes with the medication. If one is not provided, ask your pharmacist for a suitable measuring device.
If you are taking this medication to treat cold sores, chickenpox, shingles, or genital herpes, start taking it as soon as symptoms appear. The medication may not be effective if you start taking it too late. Continue taking the medication as directed by your doctor or healthcare provider, even if you start feeling better.
Storing and Disposing of Your Medication
Store your medication at room temperature, away from light and moisture. Keep it in a dry place, such as a closet or drawer, and avoid storing it in the bathroom. Keep all medications out of the reach of children and pets.
When your medication is no longer needed or has expired, dispose of it properly. Do not flush it down the toilet or pour it down the drain unless instructed to do so by your pharmacist. Check with your pharmacist for guidance on the best way to dispose of your medication, and consider participating in a drug take-back program in your area.
What to Do If You Miss a Dose
If you miss a dose, take it as soon as you remember. However, if it is close to the time for your next dose, skip the missed dose and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses to make up for a missed dose.
To get the most benefit from your medication, follow your doctor's instructions carefully. Read all the information provided with your prescription and follow the instructions closely. You can take this medication with or without food, but if it causes stomach upset, take it with food to help minimize this side effect.
Before taking a liquid dose, shake the bottle well. To ensure accurate dosing, use the measuring device that comes with the medication. If one is not provided, ask your pharmacist for a suitable measuring device.
If you are taking this medication to treat cold sores, chickenpox, shingles, or genital herpes, start taking it as soon as symptoms appear. The medication may not be effective if you start taking it too late. Continue taking the medication as directed by your doctor or healthcare provider, even if you start feeling better.
Storing and Disposing of Your Medication
Store your medication at room temperature, away from light and moisture. Keep it in a dry place, such as a closet or drawer, and avoid storing it in the bathroom. Keep all medications out of the reach of children and pets.
When your medication is no longer needed or has expired, dispose of it properly. Do not flush it down the toilet or pour it down the drain unless instructed to do so by your pharmacist. Check with your pharmacist for guidance on the best way to dispose of your medication, and consider participating in a drug take-back program in your area.
What to Do If You Miss a Dose
If you miss a dose, take it as soon as you remember. However, if it is close to the time for your next dose, skip the missed dose and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses to make up for a missed dose.
Lifestyle & Tips
- Drink plenty of fluids while taking this medication to help prevent kidney problems.
- This medication does not cure herpes infections, nor does it prevent the spread of herpes to others. Avoid sexual contact during outbreaks.
- Take the medication exactly as prescribed, even if you start to feel better. Do not skip doses or stop early.
- For cold sores or genital herpes, start treatment as soon as symptoms appear (e.g., tingling, itching, burning).
Available Forms & Alternatives
Available Strengths:
Generic Alternatives:
Dosing & Administration
Adult Dosing
Standard Dose:
Varies by indication. E.g., Genital Herpes (initial): 200 mg (5 mL) 5 times daily for 10 days. Herpes Zoster: 800 mg (20 mL) 5 times daily for 7-10 days.
Dose Range:
200 - 800 mg
Condition-Specific Dosing:
Herpes Simplex (initial genital herpes):
200 mg (5 mL) 5 times daily for 10 days
Herpes Simplex (chronic suppressive therapy):
400 mg (10 mL) twice daily for up to 12 months, or 200 mg (5 mL) 3-5 times daily
Herpes Zoster (shingles):
800 mg (20 mL) 5 times daily for 7 to 10 days
Varicella (chickenpox):
800 mg (20 mL) 4 times daily for 5 days
Pediatric Dosing
Neonatal:
Not established for suspension, typically IV for severe HSV.
Infant:
Not established for suspension, typically IV for severe HSV.
Child:
Varicella (âĨ2 years): 20 mg/kg (max 800 mg) 4 times daily for 5 days. Mucocutaneous HSV (immunocompromised, âĨ2 years): 20 mg/kg (max 800 mg) 3 times daily for 7-14 days.
Adolescent:
Dosing similar to adult for specific indications, or weight-based for varicella/HSV if appropriate.
Dose Adjustments
Renal Impairment:
Mild:
CrCl 25-50 mL/min: Adjust dose frequency (e.g., for Zoster, 800 mg q8h).
Moderate:
CrCl 10-25 mL/min: Adjust dose frequency (e.g., for Zoster, 800 mg q12h).
Severe:
CrCl <10 mL/min: Adjust dose frequency (e.g., for Zoster, 800 mg q24h).
Dialysis:
Administer dose after dialysis. Supplemental dose may be needed.
Hepatic Impairment:
Mild:
No adjustment needed
Moderate:
No adjustment needed
Severe:
No adjustment needed
Pharmacology
Mechanism of Action
Acyclovir is a synthetic purine nucleoside analog with in vitro and in vivo inhibitory activity against herpes simplex virus types 1 (HSV-1), 2 (HSV-2), and varicella-zoster virus (VZV). It is converted to acyclovir triphosphate by viral thymidine kinase, which then inhibits viral DNA polymerase, interferes with viral DNA replication, and leads to chain termination upon incorporation into the viral DNA.
Pharmacokinetics
Absorption:
Bioavailability:
15-30% (oral)
Tmax:
1.5-2 hours
FoodEffect:
Food does not significantly affect absorption.
Distribution:
Vd:
0.8 L/kg
ProteinBinding:
9-33%
CnssPenetration:
Yes (CSF concentrations are approximately 50% of plasma concentrations)
Elimination:
HalfLife:
2.5-3.3 hours (normal renal function)
Clearance:
Not available (highly variable)
ExcretionRoute:
Renal (primarily unchanged drug)
Unchanged:
62-91%
Pharmacodynamics
OnsetOfAction:
Within hours (antiviral activity), clinical improvement within days of therapy initiation.
PeakEffect:
Varies by indication and viral load, typically within 2-3 days of consistent dosing.
DurationOfAction:
Dependent on viral replication cycle and continued dosing.
Safety & Warnings
Side Effects
Serious Side Effects: Seek Medical Help Right Away
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek medical attention immediately:
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
+ Swelling of the mouth, face, lips, tongue, or throat
Behavioral problems
Mood changes
Confusion
Hallucinations (seeing or hearing things that are not there)
Seizures
Shakiness
Dizziness or drowsiness
Abnormal burning, numbness, or tingling sensations
Changes in speech
Severe kidney problems, which may be indicated by:
+ Inability to pass urine
+ Blood in the urine
+ Changes in the amount of urine passed
+ Unexpected weight gain
Life-threatening blood disorders, such as thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS), which may be indicated by:
+ Extreme fatigue or weakness
+ Bruising or bleeding
+ Dark urine or yellow skin and eyes
+ Pale skin
+ Changes in the amount of urine passed
+ Changes in vision
+ Weakness or numbness on one side of the body
+ Trouble speaking or thinking
+ Changes in balance
+ Fever
Other Possible Side Effects
Like all medications, this drug can cause side effects. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other symptoms that bother you or do not go away, contact your doctor:
Upset stomach or vomiting
Fatigue or weakness
Reporting Side Effects
This is not an exhaustive list of 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.
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek medical attention immediately:
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
+ Swelling of the mouth, face, lips, tongue, or throat
Behavioral problems
Mood changes
Confusion
Hallucinations (seeing or hearing things that are not there)
Seizures
Shakiness
Dizziness or drowsiness
Abnormal burning, numbness, or tingling sensations
Changes in speech
Severe kidney problems, which may be indicated by:
+ Inability to pass urine
+ Blood in the urine
+ Changes in the amount of urine passed
+ Unexpected weight gain
Life-threatening blood disorders, such as thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS), which may be indicated by:
+ Extreme fatigue or weakness
+ Bruising or bleeding
+ Dark urine or yellow skin and eyes
+ Pale skin
+ Changes in the amount of urine passed
+ Changes in vision
+ Weakness or numbness on one side of the body
+ Trouble speaking or thinking
+ Changes in balance
+ Fever
Other Possible Side Effects
Like all medications, this drug can cause side effects. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other symptoms that bother you or do not go away, contact your doctor:
Upset stomach or vomiting
Fatigue or weakness
Reporting Side Effects
This is not an exhaustive list of 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:
- Signs of kidney problems (e.g., little or no urination, painful urination, swelling in your feet or ankles, feeling tired or short of breath)
- Easy bruising or bleeding, unusual weakness
- Confusion, agitation, hallucinations, seizures (rare)
- Severe skin rash or blistering
- Signs of an allergic reaction (e.g., hives, difficulty breathing, swelling of your face/lips/tongue/throat)
Before Using This Medicine
Before Taking This Medication: Important Information to Share with Your Doctor
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the symptoms you experienced as a result of the allergy.
All medications you are currently taking, including prescription and over-the-counter (OTC) drugs, natural products, and vitamins. This information will help your doctor and pharmacist identify potential interactions between this medication and other substances.
* Any existing health problems, as this medication may interact with certain conditions.
To ensure your safety, it is crucial to verify that it is safe to take this medication with all your current medications and health conditions. Never start, stop, or adjust the dosage of any medication without first consulting your doctor.
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the symptoms you experienced as a result of the allergy.
All medications you are currently taking, including prescription and over-the-counter (OTC) drugs, natural products, and vitamins. This information will help your doctor and pharmacist identify potential interactions between this medication and other substances.
* Any existing health problems, as this medication may interact with certain conditions.
To ensure your safety, it is crucial to verify that it is safe to take this medication with all your current medications and health conditions. Never start, stop, or adjust the dosage of any medication without first consulting your doctor.
Precautions & Cautions
Important Warnings and Precautions
When taking this medication, it is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are using this drug.
To stay hydrated, drink plenty of non-caffeinated liquids every day, unless your doctor advises you to limit your fluid intake.
If you are 65 years or older, use this medication with caution, as you may be more susceptible to side effects.
If you are pregnant, planning to become pregnant, or breastfeeding, consult your doctor to discuss the potential benefits and risks to you and your baby.
Herpes Infection Considerations
This medication is not a cure for herpes infections. Consult your doctor to understand the treatment goals and expectations.
If you have genital herpes, note that this medication will not prevent the spread of the infection. Avoid any sexual activity when you have active sores or other symptoms of genital herpes. Even in the absence of visible symptoms, genital herpes can still be transmitted to others. To reduce the risk of transmission, use a latex or polyurethane condom during sexual activity and consult your doctor for guidance.
When taking this medication, it is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are using this drug.
To stay hydrated, drink plenty of non-caffeinated liquids every day, unless your doctor advises you to limit your fluid intake.
If you are 65 years or older, use this medication with caution, as you may be more susceptible to side effects.
If you are pregnant, planning to become pregnant, or breastfeeding, consult your doctor to discuss the potential benefits and risks to you and your baby.
Herpes Infection Considerations
This medication is not a cure for herpes infections. Consult your doctor to understand the treatment goals and expectations.
If you have genital herpes, note that this medication will not prevent the spread of the infection. Avoid any sexual activity when you have active sores or other symptoms of genital herpes. Even in the absence of visible symptoms, genital herpes can still be transmitted to others. To reduce the risk of transmission, use a latex or polyurethane condom during sexual activity and consult your doctor for guidance.
Overdose Information
Overdose Symptoms:
- Increased side effects such as nausea, vomiting, diarrhea, headache
- Kidney failure (e.g., decreased urine output)
- Neurological symptoms (e.g., confusion, hallucinations, seizures, coma)
What to Do:
Seek immediate medical attention or call a poison control center (1-800-222-1222). Hemodialysis can remove acyclovir from the blood.
Drug Interactions
Major Interactions
- Foscarnet (increased risk of renal toxicity)
- Mycophenolate mofetil (increased plasma concentrations of both drugs)
Moderate Interactions
- Probenecid (increases acyclovir AUC and decreases renal clearance)
- Cimetidine (increases acyclovir AUC and decreases renal clearance)
- Nephrotoxic agents (e.g., NSAIDs, aminoglycosides, cyclosporine, tacrolimus - increased risk of renal dysfunction)
- Zidovudine (reports of severe lethargy and drowsiness with concurrent use)
Monitoring
Baseline Monitoring
Renal function (BUN, serum creatinine)
Rationale: Acyclovir is primarily renally eliminated; baseline assessment is crucial for dosing adjustments, especially in elderly or those with pre-existing renal impairment.
Timing: Prior to initiation of therapy
Hydration status
Rationale: Adequate hydration is important to prevent renal tubular crystallization of acyclovir.
Timing: Prior to and during therapy
Routine Monitoring
Renal function (BUN, serum creatinine)
Frequency: Periodically, especially in patients with renal impairment, elderly, or those receiving concomitant nephrotoxic drugs.
Target: Within normal limits or stable for patient's baseline.
Action Threshold: Significant increase in BUN/creatinine; consider dose adjustment or discontinuation.
Hydration status
Frequency: Daily
Target: Adequate fluid intake, normal urine output.
Action Threshold: Signs of dehydration or decreased urine output; encourage fluids or consider IV hydration.
Signs/symptoms of adverse effects (e.g., CNS effects, GI upset)
Frequency: Daily
Target: Absence of severe or persistent adverse effects.
Action Threshold: Development of severe headache, dizziness, confusion, nausea, vomiting; evaluate and manage.
Symptom Monitoring
- Nausea
- Vomiting
- Diarrhea
- Headache
- Dizziness
- Fatigue
- Rash
- Signs of renal impairment (decreased urine output, swelling)
- Neurological changes (confusion, hallucinations, seizures - rare but serious)
Special Patient Groups
Pregnancy
Acyclovir is classified as Pregnancy Category B. Studies in animals have not shown harm to the fetus, and human data from pregnancy registries (e.g., Acyclovir in Pregnancy Registry) have not shown an increased risk of birth defects. Generally considered safe for use during pregnancy when indicated.
Trimester-Specific Risks:
First Trimester:
No increased risk of major birth defects observed in human studies.
Second Trimester:
No specific risks identified.
Third Trimester:
No specific risks identified.
Lactation
Acyclovir is excreted into breast milk. However, infant exposure is generally low, and adverse effects in breastfed infants are not expected. The American Academy of Pediatrics considers acyclovir compatible with breastfeeding. Monitor infant for diarrhea or rash.
Infant Risk:
Low
Pediatric Use
Dosing is weight-based for many indications. Close monitoring for renal function and hydration is important, especially in younger children. Safety and efficacy in neonates and infants for certain indications may not be fully established for oral suspension; IV formulation is often preferred for severe infections.
Geriatric Use
Elderly patients are more likely to have decreased renal function, which can lead to higher acyclovir concentrations and an increased risk of adverse effects, particularly CNS effects (e.g., confusion, lethargy). Dose adjustment based on renal function is crucial. Adequate hydration is also very important.
Clinical Information
Clinical Pearls
- Acyclovir is most effective when initiated at the earliest sign or symptom of a viral outbreak (e.g., within 24 hours of rash onset for chickenpox/shingles, or at the first sign of tingling for cold sores/genital herpes).
- Ensure adequate hydration to prevent renal crystallization and potential kidney injury, especially with higher doses or in patients with pre-existing renal impairment.
- Acyclovir is not a cure for herpes infections; it helps manage symptoms and reduce the frequency/severity of outbreaks.
- Resistance to acyclovir can occur, particularly in immunocompromised patients with prolonged or recurrent exposure.
- The oral suspension is useful for pediatric patients or adults who have difficulty swallowing tablets.
Alternative Therapies
- Valacyclovir (Valtrex) - prodrug of acyclovir with better oral bioavailability, allowing for less frequent dosing.
- Famciclovir (Famvir) - prodrug of penciclovir, also with better oral bioavailability than acyclovir.
- Penciclovir (Denavir) - topical cream for cold sores.
Cost & Coverage
Average Cost:
Varies widely, typically $50-$200+ per 125 mL bottle (200mg/5mL)
Generic Available:
Yes
Insurance Coverage:
Tier 1 or 2 (generic), Tier 3 (brand)
General Drug Facts
If your symptoms or health issues persist or worsen, it's essential to contact your doctor for further guidance. To ensure your safety, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so be sure to check with your pharmacist for more information. If you have any questions or concerns about your medication, don't hesitate to reach out to 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 details about the medication taken, the amount, and the time it happened.