RITEMED Aciclovir 800mg Tablet 30's
RXDRUG-DR-XY35460
Discreet Packaging
FDA-registered Products
FDA-licensed Pharmacies
Indications/Uses
For the treatment of the following infections: Herpes simplex virus infections of the skin and mucous membrane including initial and recurrent genital herpes; Varicella infections (chicken pox); Herpes zoster (shingles).
For the prevention of herpes simplex virus infections in immunocompromised patients including recurrent infections.
For the management of severely immunocompromised patients including those with advanced HIV disease (CD4+ counts <200/mm3, including patients with AIDS or severe AIDS-related complex) or following bone marrow transplantation.
For the prevention of herpes simplex virus infections in immunocompromised patients including recurrent infections.
For the management of severely immunocompromised patients including those with advanced HIV disease (CD4+ counts <200/mm3, including patients with AIDS or severe AIDS-related complex) or following bone marrow transplantation.
Dosage/Direction for Use
The dose and treatment duration depends on the type and severity of the infection. Adequate fluid intake is recommended to prevent acute renal failure or precipitation of aciclovir crystals in the renal tubules.
For severely immunocompromised patients, use of the intravenous (IV) format should be considered.
Usual Recommended Adult Dose: See Table 1.
For severely immunocompromised patients, use of the intravenous (IV) format should be considered.
Usual Recommended Adult Dose: See Table 1.
Usual Recommended Pediatric Dose: See Table 2.
Recommended Oral Dose in Patients with Impaired Renal Function: See Table 3.
Overdosage
Ingestion of up to 20 g of aciclovir has been reported. Common signs and symptoms of aciclovir overdosage include elevations in BUN and serum creatinine concentration, renal failure, agitation, coma, lethargy, and seizures. Precipitation of aciclovir crystals in the renal tubules which may cause renal dysfunction leading to renal failure and anuria have been observed when renal concentrations of aciclovir exceed 2.5 mg/mL.
Aciclovir may be removed by hemodialysis. Hemodialysis should be initiated when acute renal failure and anuria occurs following aciclovir overdosage until renal function is restored.
Aciclovir may be removed by hemodialysis. Hemodialysis should be initiated when acute renal failure and anuria occurs following aciclovir overdosage until renal function is restored.
Administration
May be taken with or without food.
Contraindications
Hypersensitivity to Aciclovir or valaciclovir or to any components of this product.
Special Precautions
Aciclovir should be used with caution in patients with impaired renal function and the dose should be adjusted accordingly. Renal failure, which in some cases led to death, have been observed during therapy. Caution should also be exercised when patients are receiving aciclovir in combination with other potentially nephrotoxic agents since this may increase the risk of renal impairment and/or the risk of reversible central nervous system (manifested by tremor, agitation, nausea, lethargy, mild disorientation, autonomic instability, hemiparesthesia, and slurred speech). Adequate fluid intake is advised.
Patients receiving aciclovir for the treatment of genital herpes should be advised that the drug is not a cure for herpes and will not prevent transmission of the infection. It is therefore advised that patients should avoid sexual contact while visible lesions are present.
The recommended dose and duration of aciclovir therapy should not be exceeded to prevent drug accumulation and decrease the risk of toxicity.
Carcinogenesis, Mutagenesis, Impairment of Fertility: In animal studies using mice and rats, maximum plasma concentrations of 3 to 6 times and 1 to 2 times human levels, respectively, did not result to statistically significant difference between the incidence of tumors between aciclovir-treated and non-treated animals, nor did aciclovir shorten the latency of tumors.
In in vitro and in vivo genetic toxicity assays, aciclovir yielded positive results in 5 out of the 16 assays.
Aciclovir did not reveal impairment of fertility in mice given 450 mg/kg orally or in rats given 25 mg/day subcutaneously (SC). However, at higher doses (50 mg/kg/day SC), implantation efficacy, but not litter size, was decreased. In peri- and post-natal studies in rats, higher doses also resulted in significant decrease in group mean numbers of corpora lutea, total implantation sites, and live fetuses.
No testicular abnormalities were seen in dogs receiving aciclovir 50 mg/kg/day IV for 1 month or aciclovir 60 mg/kg/day orally for 1 year. Testicular atrophy and aspermatogenesis were observed in rats and dogs at higher dose levels.
Use in Children: Safety and efficacy of oral aciclovir in children younger than 2 years old have not been established.
Use in Elderly: There was no overall difference in effectiveness for time to cessation of new lesion formation or time to healing between elderly and younger adults. However, duration of pain after healing was longer in older patients (65 years old) and nausea, vomiting, and dizziness were reported more frequently in elderly patients.
Adverse CNS (e.g., coma, confusion, hallucinations, somnolence) and renal effects during aciclovir therapy were more common in elderly patients. Elderly patients were also likely to require dosage adjustment and renal monitoring in elderly patients is advised.
Patients receiving aciclovir for the treatment of genital herpes should be advised that the drug is not a cure for herpes and will not prevent transmission of the infection. It is therefore advised that patients should avoid sexual contact while visible lesions are present.
The recommended dose and duration of aciclovir therapy should not be exceeded to prevent drug accumulation and decrease the risk of toxicity.
Carcinogenesis, Mutagenesis, Impairment of Fertility: In animal studies using mice and rats, maximum plasma concentrations of 3 to 6 times and 1 to 2 times human levels, respectively, did not result to statistically significant difference between the incidence of tumors between aciclovir-treated and non-treated animals, nor did aciclovir shorten the latency of tumors.
In in vitro and in vivo genetic toxicity assays, aciclovir yielded positive results in 5 out of the 16 assays.
Aciclovir did not reveal impairment of fertility in mice given 450 mg/kg orally or in rats given 25 mg/day subcutaneously (SC). However, at higher doses (50 mg/kg/day SC), implantation efficacy, but not litter size, was decreased. In peri- and post-natal studies in rats, higher doses also resulted in significant decrease in group mean numbers of corpora lutea, total implantation sites, and live fetuses.
No testicular abnormalities were seen in dogs receiving aciclovir 50 mg/kg/day IV for 1 month or aciclovir 60 mg/kg/day orally for 1 year. Testicular atrophy and aspermatogenesis were observed in rats and dogs at higher dose levels.
Use in Children: Safety and efficacy of oral aciclovir in children younger than 2 years old have not been established.
Use in Elderly: There was no overall difference in effectiveness for time to cessation of new lesion formation or time to healing between elderly and younger adults. However, duration of pain after healing was longer in older patients (65 years old) and nausea, vomiting, and dizziness were reported more frequently in elderly patients.
Adverse CNS (e.g., coma, confusion, hallucinations, somnolence) and renal effects during aciclovir therapy were more common in elderly patients. Elderly patients were also likely to require dosage adjustment and renal monitoring in elderly patients is advised.
Use In Pregnancy & Lactation
Pregnancy: (Pregnancy Category B) There are no adequate and well-controlled studies in pregnant women.
In a prospective registry of aciclovir use during pregnancy, data collected from 1984 to April 1999 showed that there is no evidence of an increased risk for birth defects in infants of mothers treated with aciclovir during the first trimester of pregnancy. However, sample size of the registry (756 outcomes) is insufficient to evaluate the risk for less common defects or to permit reliable or definitive conclusions regarding safety of aciclovir in pregnant women. The use of the drug during pregnancy should justify potential benefits to the women against potential risks to the fetus.
Lactation: Aciclovir passes into breast milk and levels can be three to four times higher than in serum. Therefore, aciclovir should be used with caution by breastfeeding women and should only be used when there is no other suitable alternative.
In a prospective registry of aciclovir use during pregnancy, data collected from 1984 to April 1999 showed that there is no evidence of an increased risk for birth defects in infants of mothers treated with aciclovir during the first trimester of pregnancy. However, sample size of the registry (756 outcomes) is insufficient to evaluate the risk for less common defects or to permit reliable or definitive conclusions regarding safety of aciclovir in pregnant women. The use of the drug during pregnancy should justify potential benefits to the women against potential risks to the fetus.
Lactation: Aciclovir passes into breast milk and levels can be three to four times higher than in serum. Therefore, aciclovir should be used with caution by breastfeeding women and should only be used when there is no other suitable alternative.
Adverse Reactions
Renal effects: Increased blood urea nitrogen (BUN) and/or serum creatinine concentrations, anuria, and hematuria have occurred with oral aciclovir use while abnormal urinalysis manifested by increase in formed elements in urine sediment and pain or pressure on urination have been reported with IV aciclovir use. Renal failure which may result in death were reported in some patients. Alteration in renal function were also reported although in most cases, this undesirable effect resolves spontaneously or following improved hydration and electrolyte balance, dosage adjustment, or drug discontinuance.
Nervous system effects: Headache is the most common nervous system adverse effect reported during chronic aciclovir therapy. Aggressive behavior, agitation, ataxia, coma, confusion, decreased consciousness, delirium, dizziness, encephalopathy, hallucinations, obtundation (reduced or dulled level of alertness or consciousness), paresthesia, psychosis, seizures, somnolence, and tremors were also reported and were most frequently seen with use of aciclovir in elderly patients or patients with impaired renal function. Malaise has also occurred in patients receiving aciclovir for the treatment of herpes zoster.
Reports of cerebral edema, coma, and death were observed following IV use of aciclovir.
Gastrointestinal effects: Nausea, vomiting, and diarrhea are the most common adverse effects of oral aciclovir. Anorexia, diarrhea, and gastrointestinal distress have been reported with IV aciclovir.
Hematologic effects: Patients receiving oral aciclovir have reported anemia, leukocytoclastic vasculitis, leukopenia, lymphadenopathy, and thrombocytopenia.
Dermatologic and Sensitivity Reactions: There have been occasional reports of rash, pruritus, or urticaria. Alopecia and angioedema have also occurred. Rarely, anaphylaxis, Stevens-Johnson syndrome, erythema multiforme, photosensitivity, rash, and toxic epidermal necrolysis have been reported.
Other Adverse Effects: Fever and pain have occurred during oral aciclovir therapy. Rarely, there have been reports of elevated liver function test results, hepatitis, hyperbilirubinemia, jaundice, hypotension, myalgia, peripheral edema, thirst, and visual abnormalities in patients receiving aciclovir.
Nervous system effects: Headache is the most common nervous system adverse effect reported during chronic aciclovir therapy. Aggressive behavior, agitation, ataxia, coma, confusion, decreased consciousness, delirium, dizziness, encephalopathy, hallucinations, obtundation (reduced or dulled level of alertness or consciousness), paresthesia, psychosis, seizures, somnolence, and tremors were also reported and were most frequently seen with use of aciclovir in elderly patients or patients with impaired renal function. Malaise has also occurred in patients receiving aciclovir for the treatment of herpes zoster.
Reports of cerebral edema, coma, and death were observed following IV use of aciclovir.
Gastrointestinal effects: Nausea, vomiting, and diarrhea are the most common adverse effects of oral aciclovir. Anorexia, diarrhea, and gastrointestinal distress have been reported with IV aciclovir.
Hematologic effects: Patients receiving oral aciclovir have reported anemia, leukocytoclastic vasculitis, leukopenia, lymphadenopathy, and thrombocytopenia.
Dermatologic and Sensitivity Reactions: There have been occasional reports of rash, pruritus, or urticaria. Alopecia and angioedema have also occurred. Rarely, anaphylaxis, Stevens-Johnson syndrome, erythema multiforme, photosensitivity, rash, and toxic epidermal necrolysis have been reported.
Other Adverse Effects: Fever and pain have occurred during oral aciclovir therapy. Rarely, there have been reports of elevated liver function test results, hepatitis, hyperbilirubinemia, jaundice, hypotension, myalgia, peripheral edema, thirst, and visual abnormalities in patients receiving aciclovir.
Drug Interactions
Antifungal Agents: In in vitro replication studies, co-administration of amphotericin B and aciclovir results in the potentiation of antiviral activity of aciclovir against pseudorabies virus. Combination therapy of ketoconazole and aciclovir shows dose-dependent, synergistic antiviral activity against herpes simplex virus type 1 and 2. However, clinical importance of these interactions has not been established.
Probenecid: Concurrent administration of probenecid and aciclovir results in increased mean plasma half-life and area under the plasma concentration time-curve (AUC) and decreased urinary excretion and renal clearance of aciclovir. This interaction may be due to competitive inhibition of the renal secretion of aciclovir.
Interferon: Concomitant administration of aciclovir and interferon results in additive or synergistic antiviral effect against herpes simplex type 1. However, clinical importance of the interaction is unknown.
Zidovudine: Administration of aciclovir IV, together with zidovudine, in one AIDS patient resulted in neurotoxicity characterized by profound drowsiness and lethargy. These undesirable effects recurred during rechallenge. Neurotoxicity was seen within 30 to 60 days after initiation of IV therapy, persisted with some improvement when aciclovir was administered orally, and resolved following discontinuation of therapy. Since combination use of these drugs may be necessary for the treatment and prevention of opportunistic infections, patients receiving both drugs should be closely monitored.
Probenecid: Concurrent administration of probenecid and aciclovir results in increased mean plasma half-life and area under the plasma concentration time-curve (AUC) and decreased urinary excretion and renal clearance of aciclovir. This interaction may be due to competitive inhibition of the renal secretion of aciclovir.
Interferon: Concomitant administration of aciclovir and interferon results in additive or synergistic antiviral effect against herpes simplex type 1. However, clinical importance of the interaction is unknown.
Zidovudine: Administration of aciclovir IV, together with zidovudine, in one AIDS patient resulted in neurotoxicity characterized by profound drowsiness and lethargy. These undesirable effects recurred during rechallenge. Neurotoxicity was seen within 30 to 60 days after initiation of IV therapy, persisted with some improvement when aciclovir was administered orally, and resolved following discontinuation of therapy. Since combination use of these drugs may be necessary for the treatment and prevention of opportunistic infections, patients receiving both drugs should be closely monitored.
Storage
Store at temperatures not exceeding 30°C.
Action
Pharmacology: Aciclovir, a synthetic purine nucleoside analog, is active against herpes simplex virus (HSV), varicella-zoster virus and, to a lesser extent, Epstein-Barr virus. Aciclovir's activity is dependent upon intracellular activation of the drug to aciclovir triphosphate by viral thymidine kinase. Aciclovir triphosphate inhibits viral DNA synthesis and replication by inhibiting the herpes virus DNA polymerases and by incorporating into the growing viral DNA primer template and inactivation of the polymerase. This activity is, however, highly selective for infected viral cells since aciclovir triphosphate is formed in virally infected cells 40 to 100 times greater than in normal uninfected cells.
After oral administration, absorption of aciclovir in the gastrointestinal (GI) tract is variable and incomplete and is estimated to amount only to 10% to 30% of an oral dose. Aciclovir's bioavailability decreases with increasing doses and steady-state peak and trough concentration are not dose proportional that it has been suggested that GI absorption may be saturable. Aciclovir is slowly absorbed in the GI tract with a time to reach peak concentrations of about 1.5 to 2 hours. After multidose administration, steady-state plasma concentrations are achieved by the second day.
In a study in healthy volunteers, administration of 200 mg, 400 mg, and 800 mg six times daily results in steady-state peak and trough concentrations of 0.83 and 0.46 mg/L, 1.21 and 0.63 mg/L, and 1.61 and 0.83 mg/L, respectively.
Aciclovir is not affected by food.
Aciclovir is widely distributed into body tissues and fluids including the brain, kidneys, liver, lungs, muscle, spleen, uterus, vaginal mucosa, vaginal secretions, cerebrospinal fluid (CSF), and herpetic vesicular fluid. After multidose therapy, concentrations in the kidneys and lungs were 10 to 13 times the plasma concentration and 25% to 70% of the plasma level was found in the brain, spinal cord, and CSF.
Aciclovir's plasma half-life ranges from 2.5 to 3.3 hours in adult patients with normal renal function. In infants younger than 3 months, the plasma half-life maybe slightly prolonged to about 3.8 hours while in patients with impaired renal function, the mean terminal plasma half-life is about 19.5 hours.
In adult patients with normal renal function, renal excretion is the major route of elimination with about 9% to 20% of an oral dose excreted unchanged in the urine. Renal clearance of aciclovir is approximately threefold greater than the creatinine clearance indicating tubular secretion as well as glomerular filtration.
Aciclovir is removed by hemodialysis with a half-life of 5 hours which results in a 60% decrease in the plasma concentration following a 6 hour dialysis. An additional aciclovir dose should therefore be administered after each dialysis session. Peritoneal dialysis does not appreciably remove the drug from the serum that no supplemental dose is needed during peritoneal dialysis.
Resistance: In vitro and in vivo resistance to aciclovir results mainly from selection of mutant herpes simplex virus deficient in thymidine kinase. Other resistance mechanisms include alteration of substrate specificity of thymidine kinase and reduced sensitivity of viral DNA polymerase. Resistance has also been reported with varicella-zoster virus, probably due to the same mechanisms.
Occasional treatment failures have been reported although no major problems in treating herpes simplex infections have occurred. However, resistant viruses are a major concern in treating immunocompromised patients, particularly AIDS patients, who are prone to aciclovir-resistant mucocutaneous herpes simplex virus infections.
Viruses resistant to aciclovir due to the absence of thymidine kinase may exhibit cross-resistance with other antivirals such as brivudine, idoxuridine, and ganciclovir. Viruses resistant to aciclovir due to alteration of substrate specificity of thymidine kinase may also be resistant to brivudine while those with altered DNA polymerase sensitivity may be resistant to brivudine and vidarabine. However, resistant viruses with altered enzyme specificity or sensitivity tend to have variable cross-resistance patterns and may be relatively susceptible to the antivirals mentioned previously.
After oral administration, absorption of aciclovir in the gastrointestinal (GI) tract is variable and incomplete and is estimated to amount only to 10% to 30% of an oral dose. Aciclovir's bioavailability decreases with increasing doses and steady-state peak and trough concentration are not dose proportional that it has been suggested that GI absorption may be saturable. Aciclovir is slowly absorbed in the GI tract with a time to reach peak concentrations of about 1.5 to 2 hours. After multidose administration, steady-state plasma concentrations are achieved by the second day.
In a study in healthy volunteers, administration of 200 mg, 400 mg, and 800 mg six times daily results in steady-state peak and trough concentrations of 0.83 and 0.46 mg/L, 1.21 and 0.63 mg/L, and 1.61 and 0.83 mg/L, respectively.
Aciclovir is not affected by food.
Aciclovir is widely distributed into body tissues and fluids including the brain, kidneys, liver, lungs, muscle, spleen, uterus, vaginal mucosa, vaginal secretions, cerebrospinal fluid (CSF), and herpetic vesicular fluid. After multidose therapy, concentrations in the kidneys and lungs were 10 to 13 times the plasma concentration and 25% to 70% of the plasma level was found in the brain, spinal cord, and CSF.
Aciclovir's plasma half-life ranges from 2.5 to 3.3 hours in adult patients with normal renal function. In infants younger than 3 months, the plasma half-life maybe slightly prolonged to about 3.8 hours while in patients with impaired renal function, the mean terminal plasma half-life is about 19.5 hours.
In adult patients with normal renal function, renal excretion is the major route of elimination with about 9% to 20% of an oral dose excreted unchanged in the urine. Renal clearance of aciclovir is approximately threefold greater than the creatinine clearance indicating tubular secretion as well as glomerular filtration.
Aciclovir is removed by hemodialysis with a half-life of 5 hours which results in a 60% decrease in the plasma concentration following a 6 hour dialysis. An additional aciclovir dose should therefore be administered after each dialysis session. Peritoneal dialysis does not appreciably remove the drug from the serum that no supplemental dose is needed during peritoneal dialysis.
Resistance: In vitro and in vivo resistance to aciclovir results mainly from selection of mutant herpes simplex virus deficient in thymidine kinase. Other resistance mechanisms include alteration of substrate specificity of thymidine kinase and reduced sensitivity of viral DNA polymerase. Resistance has also been reported with varicella-zoster virus, probably due to the same mechanisms.
Occasional treatment failures have been reported although no major problems in treating herpes simplex infections have occurred. However, resistant viruses are a major concern in treating immunocompromised patients, particularly AIDS patients, who are prone to aciclovir-resistant mucocutaneous herpes simplex virus infections.
Viruses resistant to aciclovir due to the absence of thymidine kinase may exhibit cross-resistance with other antivirals such as brivudine, idoxuridine, and ganciclovir. Viruses resistant to aciclovir due to alteration of substrate specificity of thymidine kinase may also be resistant to brivudine while those with altered DNA polymerase sensitivity may be resistant to brivudine and vidarabine. However, resistant viruses with altered enzyme specificity or sensitivity tend to have variable cross-resistance patterns and may be relatively susceptible to the antivirals mentioned previously.
MedsGo Class
Antivirals
Features
Brand
RiteMed
Full Details
Dosage Strength
800 mg
Drug Ingredients
- Aciclovir
Drug Packaging
Tablet 30's
Generic Name
Aciclovir
Dosage Form
Tablet
Registration Number
DR-XY35460
Drug Classification
Prescription Drug (RX)
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