Clorak Tablet (Acyclovir)

Adult administration

1. Treatment of herpes simplex virus infections - Administer 200 mg five times a day at 4-hour intervals for 5 days; treatment can be extended in cases of severe primary infections. - In severe immunocompromised patients or those with gastrointestinal absorption disorders, the single dose may be increased to 400 mg or intravenous administration may be considered. 2. Prevention of herpes simplex infections in patients with normal immune function - Administer 200 mg four times a day at approximately 6-hour intervals, or it may also be given as 400 mg twice a day at 12-hour intervals. 3. Subsequent dosing may be reduced to 200 mg 2 to 3 times a day to confirm efficacy after the initial effective dose reduction. 4. Patients on long-term treatment should periodically discontinue treatment every 6 to 12 months to monitor the natural course of the disease. 3. Prevention of herpes simplex infections in immunocompromised patients 1) Administer 200 mg four times a day at approximately 6-hour intervals. 2) In severely immunocompromised patients (post-bone marrow transplant, etc.) or those with gastrointestinal absorption disorders, the single dose may be increased to 400 mg or intravenous administration may be considered. 3) Administration should occur during periods of increased risk of infection. 4. Treatment of shingles infections 1) Administer 800 mg five times a day excluding bedtime at approximately 4-hour intervals for a total of 7 days. 2) In severely immunocompromised patients or those with gastrointestinal absorption disorders, intravenous administration should be considered. 3) It is best to start treatment as soon as possible after infection, as quicker treatment results in better outcomes. ○ Children 1. For the treatment of herpes simplex infections and prevention of herpes simplex infections in immunocompromised patients 1) For children over 2 years: Same as adults. 2) For children under 2 years: Half of the adult dosage. 3) There is currently no definitive data on prevention of herpes simplex virus infections in children with normal immune function. 2. Treatment of chickenpox in children over 2 years: Administer 20 mg/kg (maximum 800 mg per dose) four times a day for 5 days. Treatment should start as soon as the chickenpox rash appears, preferably within 24 hours after the rash appears. ○ Patients with kidney disorders Patients with kidney impairment are susceptible to central nervous system adverse reactions, so it is important to extend intervals or reduce dosages as necessary. 1. Treatment of herpes simplex infections Oral doses are typically lower than those caused by intravenous accumulation. However, for patients with severe kidney impairment (creatinine clearance less than 10 mL/min), it is preferable to administer 200 mg every 12 hours. 2. Treatment of shingles virus infections 1) For patients with a creatinine clearance of less than 10 mL/min, it is preferable to administer 800 mg twice a day at 12-hour intervals. 2) For patients with a creatinine clearance of 10-25 mL/min, it is preferable to administer 800 mg three times a day at 8-hour intervals.

Child administration

1. Treatment of herpes simplex infections and prevention of herpes simplex infections in immunocompromised patients - For children over 2 years: Same as adults. - For children under 2 years: Half of the adult dosage. 2. For children over 2 years

This medication should not be used by patients who have had allergic reactions to this drug or its ingredients, or to valacyclovir. Additionally, this medication contains lactose, so it should not be administered to patients with galactose intolerance, Lapp lactase deficiency or glucose-galactose malabsorption. Patients with poor kidney function should be cautious when using this medication as it may cause adverse reactions in the central nervous system. Patients with liver dysfunction should also be careful as there is a risk of worsening liver function when using this medication. Infants, children, and elderly patients should be particularly cautious when using this medication, and dosage and intervals should be adjusted appropriately. During treatment with this medication, severe allergic reactions such as anaphylaxis shock may rarely occur, so if symptoms such as difficulty breathing, decreased blood pressure, or chest tightness appear, treatment should be stopped immediately and medical help should be sought. Hypersensitivity reactions such as skin rash, fever, blisters, or urticaria may occur, so if such symptoms arise, discontinue use and consult a doctor. Rarely, various neurological symptoms such as hair loss, severe skin conditions, altered consciousness, confusion, seizures, drowsiness, tremors, and dizziness may occur, particularly more frequently in elderly patients or those with kidney disease. Multiple side effects have been reported such as decreased kidney function, blood disorders, liver function anomalies, gastrointestinal disturbances, muscle pain, arrhythmia, and urination problems, so any abnormal symptoms should be reported to a healthcare provider immediately. This medication is most effective when administered as soon as symptoms appear for herpes simplex and chickenpox, and for shingles, it should be started within 5 days after the appearance of skin symptoms and chickenpox within 3 days. Immunocompromised patients may consider intravenous treatment. During treatment with this medication, it is important to maintain adequate hydration to reduce the risk of dehydration and kidney toxicity. Patients with recurrent genital herpes should discuss with their physician whether to continue using this medication after one year of treatment. This medication may cause drowsiness or altered consciousness, so caution should be exercised when driving or operating hazardous machinery, especially for those with compromised kidney function. There may be interactions when used with other drugs, so caution is especially needed when used in conjunction with probenecid, cimetidine, theophylline, or mycophenolate mofetil. Women who are pregnant or may become pregnant should be cautious when using this medication, and nursing mothers should discontinue breastfeeding as this medication may pass into breast milk. In infants and children, it should be administered carefully in the minimum effective dose only when necessary, as safety in neonates and low-birth-weight infants has not been established. Elderly patients may have increased blood concentrations of this medicine due to reduced kidney function, so dosage and intervals should be adjusted, and adequate hydration is necessary. In cases of overdose, serious symptoms such as agitation, coma, seizures, and somnolence may occur, and it can cause kidney damage, requiring immediate medical observation and appropriate treatment. Blood dialysis may be required to control blood concentration.

Serious side effects

• Urticaria
• severe swelling (edema)
• hypotension
• difficulty breathing
• chest tightness
• shock
• anaphylactic shock
• anaphylactoid reactions
• Stevens-Johnson syndrome (SSS)
• toxic epidermal necrolysis (TEN)

Mild side effects

• Photosensitivity reactions
• fixed drug eruption
• fever
• rash
• blisters
• alopecia
• erythema multiforme
• altered consciousness
• disorientation
• difficulty concentrating

Keep this medication in a tightly closed container to prevent air and moisture from entering. It is best stored in a cool and dry place below 25 degrees Celsius.

Appearance

Light blue round tablet

Package unit

30 tablets/bottle, 100 tablets/bottle