Acyclovir 200mg Capsules
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
Pregnancy Category
B
FDA Approved
Jan 1982
DEA Schedule
Not Controlled
Overview
What is this medicine?
Acyclovir is an antiviral medicine used to treat infections caused by certain viruses, such as herpes (cold sores, genital herpes) and chickenpox or shingles. It works by stopping the virus from growing and spreading in your body.
How to Use This Medicine
Taking Your Medication
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 exactly. You can take this medication with or without food. If it causes stomach upset, taking it with food may help.
If you're taking this medication to treat cold sores, chickenpox, shingles, or genital herpes, start taking it as soon as your symptoms appear. The sooner you start, the more effective it will be. Don't delay taking your medication, as it may not work as well if you start too late.
Continue taking your medication as directed by your doctor or healthcare provider, even if you start feeling better. It's essential to complete the full course of treatment as prescribed.
Storing and Disposing of Your Medication
To keep your medication effective and safe:
Store it at room temperature, away from light and moisture.
Keep it in a dry place, such as a closet or drawer.
Avoid storing it in a bathroom, where it may be exposed to heat and humidity.
Keep all medications out of the reach of children and pets to avoid accidents.
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 by your pharmacist.
Check with your pharmacist for guidance on disposing of medications or to see if there are any drug take-back programs in your area.
Missing a Dose
If you miss a dose, take it as soon as you remember. However, if it's close to the time for your next dose, skip the missed dose and continue with your regular schedule. Do not take two doses at the same time or take extra doses to make up for a missed one.
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 exactly. You can take this medication with or without food. If it causes stomach upset, taking it with food may help.
If you're taking this medication to treat cold sores, chickenpox, shingles, or genital herpes, start taking it as soon as your symptoms appear. The sooner you start, the more effective it will be. Don't delay taking your medication, as it may not work as well if you start too late.
Continue taking your medication as directed by your doctor or healthcare provider, even if you start feeling better. It's essential to complete the full course of treatment as prescribed.
Storing and Disposing of Your Medication
To keep your medication effective and safe:
Store it at room temperature, away from light and moisture.
Keep it in a dry place, such as a closet or drawer.
Avoid storing it in a bathroom, where it may be exposed to heat and humidity.
Keep all medications out of the reach of children and pets to avoid accidents.
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 by your pharmacist.
Check with your pharmacist for guidance on disposing of medications or to see if there are any drug take-back programs in your area.
Missing a Dose
If you miss a dose, take it as soon as you remember. However, if it's close to the time for your next dose, skip the missed dose and continue with your regular schedule. Do not take two doses at the same time or take extra doses to make up for a missed one.
Lifestyle & Tips
- Take the medicine exactly as prescribed, even if you start to feel better.
- Drink plenty of fluids while taking this medicine to help prevent kidney problems.
- Acyclovir does not cure herpes infections, but it can help reduce the frequency and severity of outbreaks.
- Acyclovir does not prevent the spread of herpes to others. Avoid sexual contact during outbreaks and use barrier methods (condoms) to reduce transmission risk.
Available Forms & Alternatives
Available Strengths:
- Acyclovir 200mg/5ml Oral Susp
- Acyclovir 200mg Capsules
- Acyclovir 400mg Tablets
- Acyclovir 800mg Tablets
- Acyclovir Sodium 50mg/ml Inj, 20ml
- Acyclovir 800mg Tablets
- Acyclovir 5% Ointment 15gm
- Acyclovir 5% Ointment 30gm
- Acyclovir Sodium 50mg/ml Inj, 10ml
- Acyclovir 5% Ointment 2x5gm
- Acyclovir 5% Ointment 15gm
- Acyclovir 200mg Capsules
- Acyclovir 5% Ointment 30gm
- Acyclovir 5% Ointment 5gm
- Acyclovir 5% Cream 5gm
- Acyclovir 5% Cream 5gm
Dosing & Administration
Adult Dosing
Standard Dose:
Varies by indication
Dose Range:
200 - 800 mg
Condition-Specific Dosing:
Herpes Simplex (Genital Herpes) - Initial Episode:
200 mg orally 5 times daily for 10 days
Herpes Simplex (Genital Herpes) - Chronic Suppressive Therapy:
400 mg orally 2 times daily for up to 12 months, then re-evaluate
Herpes Simplex (Genital Herpes) - Intermittent Therapy:
200 mg orally 5 times daily for 5 days (initiate at first sign/symptom)
Herpes Labialis (Cold Sores):
200 mg orally 5 times daily for 5 days
Herpes Zoster (Shingles):
800 mg orally 5 times daily for 7 to 10 days
Varicella (Chickenpox):
800 mg orally 4 times daily for 5 days
Pediatric Dosing
Neonatal:
Not established for oral capsules; IV dosing used for neonates.
Infant:
Not established for oral capsules; IV dosing used for infants.
Child:
Varicella (Chickenpox) 2 years and older: 20 mg/kg orally 4 times daily for 5 days (max 800 mg/dose).
Adolescent:
Dosing similar to adult for specific indications (e.g., Herpes Zoster, Varicella) based on weight/age.
Dose Adjustments
Renal Impairment:
Mild:
CrCl 25-50 mL/min: Dose adjustment needed for some indications (e.g., Herpes Zoster 800 mg 3 times daily).
Moderate:
CrCl 10-25 mL/min: Dose adjustment needed (e.g., Herpes Zoster 800 mg 2 times daily).
Severe:
CrCl <10 mL/min: Dose adjustment needed (e.g., Herpes Zoster 800 mg once daily).
Dialysis:
Administer dose after hemodialysis. 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). Acyclovir is converted to acyclovir monophosphate by viral thymidine kinase, then to acyclovir triphosphate by cellular enzymes. Acyclovir triphosphate inhibits viral DNA synthesis and replication by competing with deoxyguanosine triphosphate for viral DNA polymerase, incorporating into viral DNA, and causing chain termination.
Pharmacokinetics
Absorption:
Bioavailability:
10-20% (dose-dependent, decreases with increasing dose)
Tmax:
1.5-2 hours
FoodEffect:
Food does not significantly affect absorption.
Distribution:
Vd:
0.8 L/kg
ProteinBinding:
9-33%
CnssPenetration:
Limited (CSF concentrations are approximately 50% of plasma concentrations)
Elimination:
HalfLife:
2.5-3.3 hours (normal renal function)
Clearance:
Primarily renal via glomerular filtration and tubular secretion.
ExcretionRoute:
Renal
Unchanged:
62-91%
Pharmacodynamics
OnsetOfAction:
Varies by indication and viral replication cycle; clinical improvement typically seen within days.
PeakEffect:
Not directly applicable as a single time point; sustained antiviral effect with regular dosing.
DurationOfAction:
Plasma half-life dictates dosing frequency; antiviral effect persists as long as therapeutic concentrations are maintained.
Safety & Warnings
Side Effects
Urgent 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 immediately or seek emergency medical attention:
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
Feeling confused
Hallucinations (seeing or hearing things that are not there)
Seizures
Shakiness
Feeling dizzy or sleepy
Burning, numbness, or tingling sensations that are not normal
Changes in speech
Kidney Problems
Severe and potentially life-threatening kidney problems have been reported with this medication. Contact your doctor right away if you experience:
Inability to pass urine
Blood in the urine
Changes in the amount of urine passed
Unexpected weight gain
Blood Problems
Rare but serious blood problems, such as thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS), have been reported with this medication. Seek medical help immediately if you experience:
Feeling very tired or weak
Bruising or bleeding
Dark urine or yellow skin or eyes
Pale skin
Changes in the amount of urine passed
Changes in eyesight
Weakness or numbness on one side of the body
Trouble speaking or thinking
Changes in balance
Fever
Other 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 contact your doctor if you notice any of the following:
Upset stomach or vomiting
Feeling tired or weak
If you experience any side effects that bother you or do not go away, contact your doctor for advice. 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 immediately or seek emergency medical attention:
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
Feeling confused
Hallucinations (seeing or hearing things that are not there)
Seizures
Shakiness
Feeling dizzy or sleepy
Burning, numbness, or tingling sensations that are not normal
Changes in speech
Kidney Problems
Severe and potentially life-threatening kidney problems have been reported with this medication. Contact your doctor right away if you experience:
Inability to pass urine
Blood in the urine
Changes in the amount of urine passed
Unexpected weight gain
Blood Problems
Rare but serious blood problems, such as thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS), have been reported with this medication. Seek medical help immediately if you experience:
Feeling very tired or weak
Bruising or bleeding
Dark urine or yellow skin or eyes
Pale skin
Changes in the amount of urine passed
Changes in eyesight
Weakness or numbness on one side of the body
Trouble speaking or thinking
Changes in balance
Fever
Other 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 contact your doctor if you notice any of the following:
Upset stomach or vomiting
Feeling tired or weak
If you experience any side effects that bother you or do not go away, contact your doctor for advice. 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)
- Signs of nervous system problems (e.g., confusion, agitation, hallucinations, unusual thoughts or behavior, seizures, tremors, difficulty speaking)
- Severe skin rash or blistering
- Unusual bruising or bleeding
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 allergic reaction you experienced, including any symptoms that occurred.
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 you are taking.
* Any existing health problems, as this medication may interact with certain conditions.
To ensure your safety, it is crucial to verify that this medication can be taken with all your current medications and health conditions. Never start, stop, or adjust the dose 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 allergic reaction you experienced, including any symptoms that occurred.
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 you are taking.
* Any existing health problems, as this medication may interact with certain conditions.
To ensure your safety, it is crucial to verify that this medication can be taken with all your current medications and health conditions. Never start, stop, or adjust the dose of any medication without first consulting your doctor.
Precautions & Cautions
Important Warnings and Cautions
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 daily, unless your doctor advises you to limit your fluid intake.
If you are 65 years or older, exercise caution when using this medication, 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 does not cure 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 symptoms of genital herpes. Additionally, genital herpes can still be transmitted even when you do not exhibit any symptoms. To minimize 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 daily, unless your doctor advises you to limit your fluid intake.
If you are 65 years or older, exercise caution when using this medication, 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 does not cure 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 symptoms of genital herpes. Additionally, genital herpes can still be transmitted even when you do not exhibit any symptoms. To minimize the risk of transmission, use a latex or polyurethane condom during sexual activity and consult your doctor for guidance.
Overdose Information
Overdose Symptoms:
- Nausea
- Vomiting
- Diarrhea
- Headache
- Confusion
- Hallucinations
- Seizures
- Renal failure (elevated BUN and serum creatinine)
What to Do:
Seek immediate medical attention or call Poison Control at 1-800-222-1222. Hemodialysis can significantly remove acyclovir from the blood.
Drug Interactions
Major Interactions
- Foscarnet (increased risk of renal impairment)
- Mycophenolate mofetil (increased acyclovir and mycophenolate levels)
Moderate Interactions
- Probenecid (increases acyclovir AUC and half-life by reducing renal clearance)
- Cimetidine (may increase acyclovir AUC, but less significant than probenecid)
- Nephrotoxic drugs (e.g., NSAIDs, aminoglycosides, cyclosporine, tacrolimus) - increased risk of renal dysfunction
Monitoring
Baseline Monitoring
Renal function (BUN, serum creatinine, CrCl)
Rationale: Acyclovir is primarily renally eliminated; dose adjustment is required in renal impairment.
Timing: Prior to initiation of therapy, especially in elderly or patients with known renal dysfunction.
Routine Monitoring
Renal function (BUN, serum creatinine)
Frequency: Periodically, especially in patients with pre-existing renal impairment, those receiving high doses, or concomitant nephrotoxic drugs.
Target: Within normal limits or stable for patient's baseline.
Action Threshold: Significant increase in BUN/creatinine warrants dose adjustment or discontinuation.
Hydration status
Frequency: Daily, especially with IV administration or high oral doses.
Target: Adequate fluid intake.
Action Threshold: Signs of dehydration; encourage adequate oral fluid intake.
Symptom Monitoring
- Signs of renal dysfunction (e.g., decreased urine output, edema)
- Neurological symptoms (e.g., lethargy, confusion, hallucinations, seizures, tremors) - more common in elderly or renally impaired patients
- Gastrointestinal upset (nausea, vomiting, diarrhea)
- Skin rash or itching
Special Patient Groups
Pregnancy
Acyclovir is generally considered safe for use during pregnancy (Category B). The Acyclovir Pregnancy Registry did not show an increased risk of birth defects compared to the general population. Use only if clearly needed.
Trimester-Specific Risks:
First Trimester:
No increased risk of 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, the amount transferred to the infant is generally low, and adverse effects in breastfed infants are not expected. Considered compatible with breastfeeding (L2).
Infant Risk:
Low risk; monitor infant for diarrhea or rash.
Pediatric Use
Dosing is weight-based for children, especially for varicella. Safety and efficacy in children under 2 years for varicella or for other indications in younger children are not well established for oral formulations. IV acyclovir is used in neonates and infants for severe infections.
Geriatric Use
Elderly patients are more likely to have decreased renal function, which requires dose adjustment. They are also at increased risk for neurological adverse effects (e.g., confusion, hallucinations, lethargy) due to higher systemic exposure and potential for dehydration. Monitor renal function closely and ensure adequate hydration.
Clinical Information
Clinical Pearls
- Emphasize the importance of starting acyclovir as early as possible for optimal efficacy, especially for herpes zoster (within 72 hours of rash onset) and recurrent genital herpes (at first sign of prodrome or lesion).
- Advise patients to maintain adequate hydration to prevent renal toxicity, particularly with higher doses or in patients with impaired renal function.
- Acyclovir does not eliminate latent virus and is not a cure for herpes infections.
- For chronic suppressive therapy of genital herpes, periodically re-evaluate the need for continued therapy (e.g., annually).
- Counsel patients that acyclovir does not prevent transmission of herpes, and safe sex practices should still be followed.
Alternative Therapies
- Valacyclovir (prodrug of acyclovir, better bioavailability, less frequent dosing)
- Famciclovir (prodrug of penciclovir, similar efficacy to acyclovir/valacyclovir, less frequent dosing)
Cost & Coverage
Average Cost:
$10 - $50 per 30 capsules (200mg)
Generic Available:
Yes
Insurance Coverage:
Tier 1 or 2 (Generic)
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 this 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 medical attention. When reporting the incident, be prepared to provide details about the medication taken, the amount, and the time it occurred.