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Aciclovir Intravenous Infusion for Adults
Who can administer
May be administered by registered competent doctor or nurse/midwife
Important information
- Must ensure adequate hydration and give over recommended time (to avoid potential renal tubular damage)
- See under 'Dose' for adjustments required in renal impairment
- See under 'Dose' for considerations in obesity
Available preparations
Aciclovir 250mg per 10ml vial
Zovirax 250mg vial
Reconstitution
| Aciclovir |
Already in solution Dilute further prior to administration |
|---|---|
| Zovirax brand |
Water for injection or Sodium chloride 0.9% 10ml per 250mg vial Dilute further prior to administration |
Infusion fluids
Sodium Chloride 0.9%
Glucose 5% (unlicensed) (ref 1)
Methods of intravenous administration
Intermittent intravenous infusion (administer using an electronically controlled infusion device)
| Dilute with infusion fluid to a concentration not greater than 5mg/ml (0.5%w/v) | ||
|---|---|---|
| Doses of 250 to 500mg | 100ml infusion fluid |
Administer required dose over 60 minutes Sixty minute infusion time reduces the risk of renal tubular damage |
| Doses between 501mg and 1000mg | 250ml infusion fluid | |
| Fluid restricted patient (central line) (ref 3) | May be infused at a concentration of 25mg/ml - ie 250mg per 10ml | |
Dose in adults
Herpes simplex infections (other than encephalitis) (treatment)
- Give 5mg per kg every eight hours
- Higher dose may be required in severe infection/immunocompromised. Discuss with Microbiology or Infectious Diseases (ref 2)
Herpes simplex encephalitis
- Give 10mg per kg every eight hours (for 14 to 21 days)
Herpes simplex infections (prophylaxis in immunocompromised) (ref 3)
- Give 5mg per kg every eight hours
Varicella zoster (chickenpox)or Herpes zoster(shingles)infections
- NOT immunocompromised: give 5mg per kg every eight hours
- Immunocompromised, or severe /complicated infections: give 10mg per kg every eight hours
Obesity
- Limited data available on aciclovir intravenous dosing in obesity (BMI greater than or equal to 30 kg/m2 )
- Ideal Body Weight (IBW) has been used, as dosing based on Total Body Weight can result in overdosing and subsequent toxicity
- However, use of IBW in morbidly obese patients (BMI greater than or equal to 40 kg/m2 ) can result in underdosing. Use of Adjusted body weight (Adj BW) in these patients may be considered - see calculations below(ref 4)
- Take type and severity of infection and patients renal function into account when choosing dose in obese patients
- Monitor patient for nephrotoxicity or neurotoxicity when using large doses
- Contact Microbiology or antimicrobial pharmacist for advice if necessary
- The GAPP gentamicin calculator can be used to calculate ideal and adjusted body weight (=Dosing weight) for your patient. Alternatively, the calculations may be done manually using the following formulas
- Ideal body weight (IBW) calculations (ref 2)
- Male 50kg + (2.3 x inches over 5 feet) or 50kg + (0.9 x cm over 152 cm)
- Female 45.5kg + (2.3 x inches over 5 feet) or 45.5kg + (0.9 x cm over 152 cm)
- Adjusted body weight (Adj BW) = (IBW + 0.4 x [TBW-IBW])
- (where TBW = total body weight or actual weight)
| Renal impairment | |
|---|---|
| eGFR | Dose |
| 25 to 50ml/minute/1.73m2 | give recommended dose every 12 hours |
| 10 to 25ml/minute/1.73m2 | give recommended dose once every 24 hours |
| less than 10ml/minute/1.73m2 | give 50% of recommended dose every 24 hours |
| Dialysis | consult specialist literature or pharmacy |
Monitoring
- Monitor renal function regularly
- Ensure adequate hydration
- Monitor for neurological side-effects
Storage
- Store below 250C
- Do not refrigerate as precipitation may occur
References
Zovirax SPC Sept 2021
1. Injectable medicines administration guide accessed online via Medusa 14/03/2022
2: Gapp app
3. BNF accessed online via Medicinescomplete 24/03/2022
4. Sanford Guide to antimicrobial therapy accessed online 24/03/2022
Therapeutic classification
Antiviral agent