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Drug Details

Aciclovir Tablets 200mg B.P.

• Presentation
  200mg tablets packaged in PVC/aluminum strips
• Description
  Each tablet contains 200mg of Aciclovir B.P.
• Indications
  

  Aciclovir tablets are indicated for

  • The treatment of herpes simplex virus (HSV) infections of the skin and the mucous membranes including initial and recurrent genital herpes

  • The suppression (prevention of recurrence) of recurrent herpes simplex infections in immunocompetent patients

  • The prophylaxis of herpes simplex infections in immunocompromised patients

  • The treatment of herpes zoster (shingles) and varicella (chickenpox) infections

• Adult Dosage
  

  Method of administration. Oral.

  Adults:

  Treatment of herpes simplex infections- 200mg five times daily at approximately 4-hourly intervals Treatment should continue for 5 days, but may need to be extended in severe initial infections.

  If patients are severely immunocompromised (e g following marrow transplant) or if absorption from G.I.T is impaired, the dose may be doubled to 400mg. Alternatively, intravenous therapy may be considered

  Treatment should commence as soon as possible after the start of an infection and, for recurrent infections, this should preferably be during the prodromal period or as soon as the lesions first appear

  Suppression of herpes simplex infections in immunocompromised patients 200mg four times daily at approximately 6-hourly intervals Many patients may be managed conveniently on a dosage of 400mg twice daily at approximately 12-hour intervals.

  It may be possible to titrate the dosage down to 200mg three times daily at approximately 8-hourly intervals or even twice daily at approximately 12-hourly intervals, with good effect

  Break-through infections may occur in some patients on total daily doses of 800mg

  Therapy should be interrupted every 6 to 12 months to allow reassessment of the condition.

  Prophylaxis of herpes simplex infections in immunocompromised patients- 200mg four times daily at approximately 6-hourly intervals

  If patients are severely immunocompromised (e g following marrow transplant) or if absorption from the G.I T is impaired, the dose may be doubled to 400mg Alternatively, intravenous therapy may be considered.

  The duration of the risk period will determine the duration of therapy

  Treatment of herpes zoster (shingles) and Varicella (chickenpox) infections 800mg five times daily at approximately 4-hourly intervals for 7 days. If patients are severely immunocompromised (e.g. following marrow transplant) or if absorption from the G I.T is impaired, intravenous therapy should be considered.

  Treatment should commence as soon as possible after the start of an infection in herpes zoster, better results are obtained if treatment is initiated as soon as possible after the onset of the rash

  Treatment of chickenpox in immunocompetent patients should begin within 24 hours of the onset of the rash

  Children

  Treatment of herpes simplex infections and prophylaxis of herpes simplex in immunocompromised patients Children aged 2 years and over should be given adult dosages and children under 2 years of age should be given half the adult dose.

  Treatment of varicella infections.

  Age 6 years and over	800mg four times daily
  Age 2-5 years	400mg four times daily.
  Under 2 years	200mg four times daily

  Calculating the dosage as 20mg per kg body weight (not to exceed 800mg) four times daily is more precise. Treatment should continue for 5 days There are no specific data available on the suppression of herpes simplex infections or the treatment of herpes zoster infections in immunocompetent children When treatment of herpes zoster infections is required in immunocompromised children, intravenous therapy should be considered.

  Dosage m renal impairment- Aciclovir is excreted via the kidney In the management of herpes simplex infections in patients with impaired renal function, the usual recommended oral doses will not result in accumulation of Aciclovir above levels that have been established with intravenous infusion However, for patients with severe renal impairment (creatinine clearance less than 10ml per minute), a dosage of 200mg twice daily at approximately 12- hourly intervals is recommended In the treatment of herpes zoster infections and varicella, dosage of 800mg twice daily at approximately 12-hourly intervals is recommended for patients with severe renal impairment (creatinine clearance less than 10ml per minute) and 800mg three times daily at approximately 6 to 8 hourly intervals is recommended for patients with moderate renal impairment (creatinine clearance in the range of 10 - 25ml per minute)

  Elderly

  The total aciclovir body clearance declines along with creatinine clearance in the elderly

  Adequate hydration should be ensured in elderly patients receiving high oral doses of Aciclovir

  Particular attention should be given to dosage reduction in elderly patients who have impaired renal function

• Contra Indications
  

  Aciclovir tablets are contra-indicated in patients known to be hypersensitive to aciclovir or valaciclovir or any of the excipients.

• Special Precautions
  

  Care should be taken to maintain adequate hydration in patients receiving higher dose oral regimens e.g. , for the treatment of herpes zoster infection (4 g daily), in order to avoid the risk of possible renal toxicity

  The data currently available from clinical studies are not sufficient to conclude that aciclovir therapy reduces the incidence of chickenpox-related complications in immunocompetent patients

  Results of various in-vitro and in-vivo mutagenicity tests indicate that aciclovir does not pose a genetic risk in man

  Aciclovir tablets have been shown to have no definite effects on sperm count, morphology or motility in man.

• Interactions
  

  No clinically significant interactions have been identified. Aciclovir is eliminated primarily unchanged in the urine via active renal tubular secretion. Any drugs administered concurrently that compete with this mechanism may increase aciclovir plasma concentrations. Probenecid and cimetidine increase the AUC of aciclovir by this mechanism and reduce aciclovir renal clearance Similarly, increases in plasma AUC's of aciclovir and of the inactive metabolite of mycophenolate mofetil have been shown when the drugs are co-administered. However, no dosage adjustment is necessary because of the wide therapeutic index of aciclovir.

• Adverse Drug Reactions
  

  Gastrointestinal Nausea, vomiting, diarrhoea and abdominal pains have been reported in some patients In clinical studies, no difference was found between placebo and aciclovir in the incidence of gastrointestinal events

  Haematological Very rarely, anaemia, leucopenia and thrombocytopenia.

  Hypersensitivity and skin Rashes including photosensitivity, urticaria, pruritis and rarely dyspnoea, angioedema and anaphylaxis

  Kidney Rare reports of increases in blood urea and creatinine Acute renal failure has been reported on very rare occasions.

  Liver Rare reports of reversible rises in bilirubin and liver related enzymes. Hepatitis and jaundice have been reported on very rare occasions.

  Neurological Headaches Occasionally, reversible neurological reactions, notably dizziness, confusional states, hallucinations, somnolence, convulsions and coma have been reported, usually in patients with renal impairment in whom the dosage was in excess of that recommended or with other predisposing factors.

  Other: Fatigue Occasional reports of accelerated diffuse hair loss As this type of hair loss has been associated with a wide variety of disease processes and medicines, the relationship of the event to aciclovir therapy is uncertain.