Acyclovir Stada

Aciclovir

Method of action: Antibiotics And Chemotherapeutics For Dermatological Use, Antiherpetic, Antivirals For Systemic Use

Treatment option: Varicella-Zoster, Chickenpox, Genital Herpes, Cold Sore, Skin Conditions, Infection, Empeines, Shingles, Smallpox

Medically reviewed

Marina Burgos

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 Acyclovir Stada

What is Acyclovir Stada?

Acyclovir Stada is an antiviral medication used to manage infections caused by specific types of viruses. It belongs to a class of drugs known as synthetic purine nucleoside analogues. The medication is primarily designed to interfere with the replication process of viruses, preventing them from spreading within the body.

Active Ingredient and Mechanism

The active substance in this medication is acyclovir. Acyclovir works by targeting viral DNA polymerase, an enzyme that viruses use to copy their genetic material. Once the medication enters a virus-infected cell, it is converted into an active form that incorporates itself into the viral DNA chain. This action terminates the growth of the DNA chain, effectively halting the multiplication of the virus.

Primary Uses

Acyclovir Stada is used to treat various conditions associated with the herpes simplex virus (HSV) and the varicella-zoster virus (VZV). Common applications include:

Herpes Simplex: Treatment of skin and mucous membrane infections, such as cold sores and genital herpes.
Herpes Zoster: Management of shingles, a painful skin rash caused by the reactivation of the chickenpox virus.
Chickenpox: Treatment of the initial varicella infection to reduce the duration and severity of symptoms.
Prevention: Suppression of recurrent herpes simplex infections in individuals with frequent outbreaks.

Available Forms

This medication is produced in several formulations to suit different types of infections and patient needs. These include:

Oral Tablets: Used for systemic treatment of shingles, chickenpox, and the prevention of recurrent herpes.
Topical Creams: Applied directly to the skin for localized outbreaks like cold sores.
Intravenous Infusions: Typically reserved for severe infections or for patients with weakened immune systems who require intensive antiviral therapy.

While Acyclovir Stada helps manage symptoms and speeds up the healing of sores, it is not a permanent cure for herpes or shingles. The viruses that cause these infections continue to live in the body even between outbreaks; the medication serves to control the virus during active phases or suppress its reactivation.

Regulatory References

Aciclovir on the WHO Essential Medicines List

What side effects are possible with Acyclovir Stada?

Adverse Reactions and Safety Profile

Acyclovir is generally well-tolerated, but officially documented adverse reactions span several system-organ classes, primarily affecting the gastrointestinal tract, nervous system, and skin.

Frequency	System-Organ Class and Examples
Common (1 in 10 to 1 in 100)	Headache, dizziness, nausea, vomiting, diarrhea, abdominal pains, pruritus, rashes (including photosensitivity), fatigue, fever.
Uncommon (1 in 100 to 1 in 1,000)	Urticaria (hives), accelerated diffuse hair loss.
Rare (1 in 1,000 to 1 in 10,000)	Anaphylaxis, angioedema, reversible increases in blood bilirubin and liver-related enzymes, increase in blood urea and creatinine, dyspnea.
Very Rare (less than 1 in 10,000)	Agitation, confusion, tremor, ataxia, hallucinations, psychotic symptoms, convulsions, somnolence, encephalopathy, coma, hepatitis, jaundice, acute renal failure, renal pain, leukopenia, thrombocytopenia, anemia.

Serious adverse reactions, though very rare, include anaphylaxis, angioedema, acute renal failure, and signs of encephalopathy (e.g., confusion, seizures). These neurological events are most frequently reported in patients with pre-existing renal impairment or other underlying risk factors. The drug is officially contraindicated in patients with known hypersensitivity to acyclovir, valaciclovir, or any excipients.

Population-Specific Safety Considerations

Elderly patients and individuals with impaired renal function require particular caution. Because acyclovir is primarily eliminated by renal clearance, high blood levels may occur in these groups, increasing the risk for serious neurological side effects. Dose adjustment is required for patients with known kidney impairment. Adequate hydration should be maintained, especially when taking higher doses.

Overdose and Emergency Response

Overdose Map: Overdose and when to seek help — official regulatory information for Acyclovir Stada

Element	Official Regulatory Documentation
Documented overdose presentations:	Neurological effects, including confusion, agitation, hallucinations, seizures, somnolence, and coma. Gastrointestinal effects like nausea and vomiting.
Physiological systems affected (as stated in label):	Renal system, leading to elevated serum creatinine and blood urea nitrogen, and potential renal failure due to precipitation of crystals in the renal tubules. Central Nervous System.
Dose-related or exposure-related factors (if applicable):	Accidental, repeated oral overdoses over several days. Intravenous overdosage. Overdoses given without appropriate monitoring of fluid and electrolyte balance.
Population-specific overdose notes (if applicable):	Patients with pre-existing renal impairment or underlying neurologic abnormalities are at an increased risk for developing neurotoxicity from overdose. Elderly patients are also at higher risk due to likely reduced renal function.
Emergency-response statements (as written in official documents):	Treatment is generally symptomatic and supportive. Close observation of the patient for signs of toxicity is required. Haemodialysis may be considered an option for symptomatic overdose management as it enhances the removal of aciclovir from the blood.
When immediate medical help is required (label-derived phrasing only):	Contact a health care practitioner, hospital emergency department, or regional Poison Control Centre immediately, even if symptoms are not yet apparent.

Overdose classifications (high-level)

Element	Official Regulatory Documentation
Severity classification (as defined in official documents):	Associated with potentially serious outcomes, including renal failure, neurological effects (coma, seizures), and in some cases, death has been observed.
Regulatory basis (EMA / FDA / etc.):	Derived from EMA Summary of Product Characteristics (SmPC) and FDA Prescribing Information.
Overdose-context constraints (as defined in official documents):	Toxic manifestations are generally reversible upon drug cessation; severe outcomes are more common in high-risk patients.

Resulting overdose structure

Official regulatory documents define the overdose profile primarily by its specific documented toxic effects on the central nervous and renal systems, with a clear distinction between generally less toxic oral overdoses and more severe intravenous overdosage. The official instructions mandate that urgent medical attention is necessary upon suspected overdose, as the profile includes life-threatening outcomes like renal failure and coma, particularly in vulnerable patients. The management strategy is officially defined as supportive, with the explicit mention of haemodialysis as a management option for symptomatic cases to accelerate drug removal.

Therapeutic Uses of Acyclovir Stada

What Acyclovir Stada Treats: Main Uses and Benefits

This medicine is commonly used to help with managing active viral infections caused by the Herpes simplex virus (HSV) and Varicella zoster virus (VZV). It is relevant for easing symptoms related to inflammatory or irritative states and acute nerve pain associated with conditions such as shingles, genital herpes, and cold sores. The main therapeutic benefit is that it may assist with easing the overall burden of symptoms and supports the process of lesion recovery, which helps manage acute discomfort.

Therapeutic Use Contexts

Acyclovir is also applied across therapeutic domains where long-term symptomatic support is needed in conditions involving frequent, disruptive recurrences, such as recurrent genital herpes or cold sores. It is relevant for easing symptoms related to inflammatory or irritative states and contributes to improved comfort during periods of heightened symptoms. It is also used in critical contexts to address symptom escalation in severe or systemic infections, including those affecting the nervous system or in immunocompromised patients, which assists with maintaining functional stability.

Quick Fact: Symptom Management Focus
This medication is commonly used to help manage acute pain, burning, and tingling (paresthesias) associated with active viral outbreaks, contributing to improved day-to-day comfort during symptomatic periods.

Regulatory References

NIH MedlinePlus Drug Information

Eligibility and Restrictions for Use

Who Can and Cannot Use Acyclovir Stada?

This section outlines the official population eligibility rules for Aciclovir (the active ingredient in Acyclovir Stada) as defined by government regulatory authorities.

Contraindications and Prohibited Use

The medicine is contraindicated and must not be used by individuals with a known hypersensitivity (allergy) to aciclovir, valaciclovir, or any component of the specific formulation. This represents an absolute exclusion from eligibility.

Age-Based Eligibility and Restrictions

Age Group	Eligibility Status	Key Restriction/Condition
Adults and Adolescents	Approved for Standard Use	N/A
Children and Infants	Approved for Conditional Use	Use is restricted to specific indications and precise dosage rules.
Elderly Patients (65+)	Approved for Conditional Use	Require close monitoring and potential dose reduction due to likely reduced kidney function.

Conditional Use and Special Populations

Use of Aciclovir is conditional on patient health status in specific populations:

Renal Impairment: Patients with reduced kidney function are eligible only if they receive a mandatory dose adjustment to prevent toxicity, as the drug is cleared by the kidneys.
Pregnancy and Breastfeeding: Use is permitted only after a formal risk-benefit assessment, where the potential benefit to the mother is determined to outweigh the potential risk to the fetus or infant.
Other Comorbidities: Caution and monitoring are advised for patients with underlying neurological abnormalities or severe hepatic abnormalities.

What should I know about interactions with other medicines?

Interactions with other medicines and products

Interactions involving oral or intravenous formulations of acyclovir primarily relate to its elimination pathway via the kidneys. Caution is advised when this medicine is used alongside other products that may affect renal function or compete for renal clearance.

Documented Pharmacokinetic Interactions

Probenecid (used for gout) is known to interfere with the kidney's active tubular secretion process. Co-administration of probenecid with acyclovir may increase the blood levels of acyclovir and prolong its half-life, raising the potential for toxicity. A similar interaction may occur with other medicines that share this renal excretion mechanism.
Concomitant use of acyclovir with Tenofovir (a medicine for HIV/HBV) or other products that are also eliminated through the kidney and compete for active tubular secretion may alter the serum concentrations of either or both medicines.

Increased Risk of Organ Toxicity

Acyclovir, especially at high doses or in patients with reduced kidney function, carries an intrinsic risk of nephrotoxicity (damage to the kidneys). This risk may be significantly increased when acyclovir is administered with other nephrotoxic medicinal products (e.g., certain antibiotics or immunosuppressants). Close monitoring of kidney function is essential in these combinations.

Specific Population and Formulation Notes

Elderly patients and individuals with existing kidney impairment require careful monitoring and potential dose adjustment, as their reduced renal function affects the elimination of acyclovir.
For systemic use (oral or IV), maintaining adequate hydration is a procedural requirement to mitigate the risk of kidney-related complications.
The topical cream formulation has minimal systemic absorption and is generally not associated with clinically significant drug-drug interactions.

Mechanism of Action

Acyclovir Stada: Mechanism of Action

Acyclovir undergoes selective biochemical modification, resulting in targeted inhibition of viral DNA synthesis. The core mechanistic domains involve its transformation into an active analog and its direct engagement with the viral genetic machinery.

Viral Enzyme-Mediated Activation

This process begins with the compound being preferentially catalyzed by viral thymidine kinase (an enzyme specific to infected cells) into acyclovir monophosphate. This step confers high specificity for phosphorylation, primarily restricting subsequent biochemical activity to cells expressing the viral enzyme.

Targeted DNA Synthesis Inhibition

The resulting triphosphorylated nucleoside analog acts as a competitive substrate, facilitating its incorporation into the elongating viral DNA strand. The absence of a 3’-hydroxyl group on the incorporated analog leads to DNA chain termination and subsequent irreversible inhibition of the viral DNA polymerase. This mechanism dictates the compound's effect profile by limiting viral genome replication.

Dosage and Administration Information

How to Use Acyclovir Stada: Official Administration Guidelines

Aciclovir is administered via oral (tablets, suspension), topical (cream, ointment), and intravenous (IV) infusion routes, which determines the specific dosage form required for use. The administration protocol is strictly defined for clinical use.

Dosing and Frequency

Dosing regimens vary widely by the context of use (acute treatment vs. chronic suppression) and the patient's condition. Treatment should be initiated as early as possible upon the first signs or symptoms (prodrome) of an episode.

Regimen Example	Typical Dose & Frequency	Course Duration
Acute Oral Treatment	200 mg to 800 mg, typically five times daily (omitting the night dose)	5 to 10 days
Chronic Suppression	400 mg twice daily (or equivalent daily dose)	Up to 12 months, followed by re-evaluation
IV Administration	5 mg/kg to 10 mg/kg body weight every 8 hours	Varies (e.g., 5 to 21 days)

Administration Conditions and Adjustments

Food Intake: Oral formulations may be taken with or without food.
Hydration: Maintaining adequate fluid intake is essential, especially with higher oral doses or IV treatment, as aciclovir is eliminated primarily through the kidneys.
IV Administration: Intravenous aciclovir must be administered by slow infusion over a minimum of one hour and requires prior deletion to a specified concentration. The dose for obese patients is typically calculated using Ideal Body Weight (IBW).
Renal Impairment: For patients with impaired kidney function, dose adjustment is mandatory. The dose or dosing frequency must be reduced based on the calculated Creatinine Clearance (CrCl) to prevent accumulation, with older adults often requiring consideration for adjustment due to potential age-related changes in renal function.

Recent Clinical Evidence

Research evidence / Overview of Studies for Acyclovir Stada

Evidence for use in Genital Herpes

Research has explored the use of Acyclovir Stada, primarily through short-term randomized controlled trials (RCTs). These studies focused on outcomes describing episodic or acute changes, monitoring how symptoms evolved in the observed populations during an outbreak. The research examined the product's use during periods of increased symptom activity and research also focused on patient-reported experiences related to physical discomfort. Findings describe patterns observed in these studies, where research highlights changes measured during the study period related to the time until symptoms subsided or the frequency of subsequent episodes in a continuous regimen.

What remains uncertain about this evidence base is the long-term characterization of outcomes reflecting daily functioning or activity level. Follow-up durations were limited in most trials, meaning there is limited information for long-term outcomes related to sustained quality of life.

Evidence for use in Herpes Zoster (Shingles)

Studies have evaluated the product in adult populations during the period of a symptomatic outbreak. Outcomes monitored included patient-reported outcomes describing perceived discomfort and the duration of pain after the rash healed (postherpetic neuralgia). Studies report how symptoms evolved in the observed populations over defined time intervals. Findings indicate patterns related to the reported duration and severity of the acute painful phase, as observed in the study populations.

The research exploring short-term symptom changes helps contextualize how patients reported their experience, but certainty remains low regarding outcomes related to persistent, long-term nerve pain.

Evidence for use in Varicella Zoster (Chickenpox)

Research describes studies monitoring outcomes linked to inflammatory or irritative states, such as the number of skin lesions and the presence of fever. The product was evaluated in studies involving this condition, particularly in children. The studies monitored responses over defined time intervals to record the time until the lesions crusted over and how symptoms evolved in the observed populations. The results apply only to the populations studied, and data for older adolescents or adults who acquire chickenpox are often limited.

What is still uncertain about Acyclovir Stada

The current body of research provides context regarding short-term symptom patterns but highlights several areas of uncertainty. Comparative evidence is lacking against other established antiviral agents for many indications, meaning subgroup findings are uncertain. Long-term effects are not fully established, as follow-up durations were limited in most trials. Data are still emerging for specific groups, and results apply only to the populations studied.

Key Studies & References

Acyclovir - StatPearls - NCBI Bookshelf (General Drug Information & Indications)

Frequently Asked Questions (FAQ)

Common questions about Acyclovir Stada (FAQ)

Q: What are the most common side effects people report when taking Acyclovir Stada?

According to official product information, the most commonly reported adverse reactions are generally mild. These include feelings such as headache, dizziness, nausea, vomiting, diarrhea, and fatigue. These are the effects most frequently observed in clinical studies and patient reporting.

Q: Can Acyclovir Stada interact with common over-the-counter pain relievers like ibuprofen?

Official information advises caution when Acyclovir is used alongside other medicines that can affect kidney function. This is because Acyclovir is eliminated through the kidneys, and combining it with certain drugs can increase the risk of kidney-related toxicity. Patients are generally advised to discuss all over-the-counter pain relievers and other products with a healthcare provider.

Q: Is it true that Acyclovir Stada doesn't actually cure the virus, but just manages outbreaks?

Regulatory information indicates Acyclovir is an antiviral medicine that works by slowing the growth and spread of the virus within the body. Official patient information confirms that it is not a cure. The virus remains dormant in the body even when symptoms are absent.

Q: Why do some people experience nausea when starting a course of Acyclovir Stada?

Nausea is listed as a common adverse reaction in the official product information. This indicates that some people may experience digestive discomfort when taking the medication. Gastrointestinal effects are frequently reported when taking oral medications.

Q: Do I need a prescription to buy Acyclovir Stada?

For systemic use (such as tablets, oral suspension, or IV forms), Acyclovir is generally classified as a prescription-only medicine (Rx). A valid prescription from a licensed healthcare provider is required to receive this medication.

Q: Is Acyclovir Stada safe for older adults or seniors?

Acyclovir is indicated for use in older adults, but specific caution is advised. Regulatory documents note that potential dose reduction is often necessary due to the likelihood of reduced kidney function, which affects drug clearance. Maintaining adequate hydration is also essential for this group.

Q: What kind of research evidence supports the use of Acyclovir Stada for herpes zoster (shingles)?

Official product information is supported by studies that confirm its clinical effectiveness for treating herpes zoster. Findings from clinical research indicate that Acyclovir can help mitigate the severity and duration of the acute phase of the outbreak in the populations studied.

Q: Can taking Acyclovir Stada affect the results of other blood tests?

Yes, official safety information lists rare side effects that can include temporary and reversible increases in certain substances measured by blood tests. These increases have been noted for blood bilirubin, liver-related enzymes, blood urea, and creatinine.

Q: How long does Acyclovir Stada typically stay in your system after you stop taking it?

The plasma elimination half-life is typically short. In patients with normal kidney function, the half-life is generally reported to be between two and four hours. This indicates the medicine is cleared from the body relatively quickly.

Q: Is there a different formulation of Acyclovir Stada, like a cream or liquid, besides the tablets?

The active ingredient, Aciclovir, is available in several pharmaceutical forms to suit different administration routes. These include tablets, oral suspension (liquid), solution for infusion (IV), and topical cream or ointment.

Q: What should I do if I miss a dose of Acyclovir Stada?

If a dose is missed, official patient information generally advises taking it as soon as it is remembered. If it is almost time for the next scheduled dose, the missed dose should be skipped, and the regular schedule should be resumed. Double dosing is generally not advised to make up for a missed dose.

Q: Are there any dietary restrictions or foods to avoid while on Acyclovir Stada?

Official dosing guidelines state that oral formulations may be taken with or without food. There are no specific foods or dietary restrictions listed in regulatory documents that are known to interact with the medication or impact its effectiveness.

Q: Does Acyclovir Stada work for all types of herpes viruses?

No. Official indications show the medicine is approved for infections caused by the Herpes simplex virus (HSV) and the Varicella zoster virus (VZV). It is not indicated for all types of viruses in the wider human herpesvirus family.

Q: Can you feel tired or dizzy while taking Acyclovir Stada?

Yes, dizziness and fatigue (tiredness) are explicitly listed in the official documents as common adverse reactions. If these symptoms are experienced, it is recommended to speak with a healthcare provider.

Q: Is there a maximum amount of time someone can continuously use Acyclovir Stada?

For chronic suppressive therapy, regulatory guidelines suggest that treatment is typically recommended for up to 12 months. After this period, a physician should re-evaluate the need for continued treatment.

Q: Is it normal to have a headache in the first few days of taking Acyclovir Stada?

Headache is listed as a common adverse reaction in official product information. This indicates that it is a frequent occurrence and may begin soon after starting treatment.

Q: Why do doctors prescribe Acyclovir Stada for long-term suppressive therapy?

Acyclovir is indicated for the suppression (prevention of recurrences) of recurrent herpes simplex infections. The purpose of long-term therapy is to reduce the frequency and severity of future outbreaks.

Q: What happens if I stop taking Acyclovir Stada before the prescribed course is finished?

Official patient information emphasizes the need for completing the full prescribed course of treatment. Prematurely stopping the medication may risk the viral infection not being completely treated.

Q: Why is it important to start Acyclovir Stada treatment as soon as symptoms appear?

Regulatory dosing guidelines emphasize that treatment should be initiated as early as possible upon the first signs or symptoms (known as the prodrome) of an episode. This early start is when the medicine is determined to be most effective.

Q: What kind of studies have been done on the safety of Acyclovir Stada in children?

The safety and efficacy of Acyclovir have been established for specific indications and age groups through pediatric trials and clinical studies. For example, it is approved for use in children aged two years and older for chickenpox.

Q: Can Acyclovir Stada make your skin more sensitive to sunlight?

Yes, official safety information lists rashes, including those related to photosensitivity, as common adverse reactions. Patients are often advised to take precautions to protect skin from direct sunlight when using medications that may cause photosensitivity.

Q: Is the absorption of Acyclovir Stada affected by other digestive medicines?

Yes, regulatory documents note that there is a known interaction with cimetidine, a medicine used for stomach ulcers. This interaction can alter the concentration of Acyclovir in the bloodstream.

Q: Can Acyclovir Stada be used for conditions other than those listed in the package insert?

Acyclovir is approved and indicated only for the specific viral infections listed in the official product information, which defines its authorized therapeutic uses.

Q: What is the shelf life of Acyclovir Stada tablets once purchased?

The shelf life of Acyclovir tablets is determined by the manufacturer and can be found printed on the packaging as the expiration date. In many cases, regulatory documents specify a shelf life of 36 months for unopened packages.

Q: Does taking Acyclovir Stada make you feel better generally, or just target the virus?

Acyclovir is a targeted antiviral drug indicated for managing viral multiplication and mitigating the severity of outbreaks. While it is not approved for a general feeling of well-being, fatigue is listed as a common adverse reaction, which suggests systemic effects can occur.

Q: Why do people sometimes need to switch from oral tablets to an IV form of acyclovir?

The intravenous (IV) form of acyclovir is typically indicated for more severe viral infections, for patients who are immunocompromised, or in cases where there are concerns about the patient's ability to properly absorb the medication through the oral route.

Q: Can Acyclovir Stada be stored in a pill box or does it need to stay in its original container?

Official storage requirements emphasize that the medicine must be protected from light and moisture. To ensure stability and potency, it is recommended to keep the tablets in their original container, tightly closed.

Q: Is it possible to develop a tolerance to Acyclovir Stada over many years of use?

Official regulatory documents do not mention user-developed 'tolerance.' However, they do refer to the potential for the virus itself to develop 'reduced sensitivity' or 'resistance' to acyclovir. This is primarily noted in immunocompromised patients following prolonged or repeated treatment.

How should Acyclovir Stada be stored and disposed of?

Official Storage and Disposal Requirements

Acyclovir tablets must be stored at controlled room temperature, specifically between 59 F and 77 F (15 C and 25 C). The product requires protection from moisture and light and should be kept in its original container, tightly closed.

Storage Restriction	Requirement
Temperature Range	15 C to 25 C
Environmental	Protect from moisture and light
Child Safety	Keep out of the sight and reach of children

Disposal must follow the FDA guidelines for unused medicine, as the product is not on the official flush list. The preferred method is using a drug take-back program. If this is unavailable, the medicine should be mixed with an unappealing substance (like dirt or coffee grounds) in a sealed plastic bag and thrown into the household trash.

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