Drugs During Pregnancy and Lactation: Treatment Options and Risk Assessment, 2nd edition (2007) ed. Schaefer, C., Peters, P. and Miller, R. Elsevier, London. As the aciclovir plasma concentrations following topical application are below the limit of detection, no pharmacokinetic studies are available on topical aciclovir. Therefore, the following data is based on the data after oral or intravenous administration.

Aciclovir cream is not intended for use in your mouth or vagina, or near your eyes. This is because it may irritate these parts of your body. If you have sores in any of these areas, you should make an appointment to see your doctor, as alternative preparations can be prescribed which will be suitable for you to use. Rabbits had 1, 3 or 6% aciclovir cream in a white petrolatum vehicle introduced directly into both eyes 5 times daily at 90-minute intervals for 3 weeks. Neither autopsy nor inspection nor histological examination revealed any pathological changes in the rabbit eyes. The manufacturer indicates that the nursing infant will receive an insignificant amount of aciclovir following maternal topical use. Whilst aciclovir is found in breast milk, the highest maternal systemic dosages only result in the infant receiving a dose 1% of that which might be prescribed. This would not be expected to result in any adverse effect in breastfed infants.

Pregnancy & Breastfeeding use

Not recommended for use by patients who know they are immunocompromised e.g. by HIV infection, bone marrow transplant or cancer treatment, except on the advice of a doctor. Such individuals should be encouraged to consult a physician concerning the treatment of an infection.

Plasma protein binding is reported to range between 9 and 33% as a function of dose. The volume of distribution at steady state in adults is 50± 8.7 1.73 m 2, or 0.7 I/kg. There is no experience of the effect of aciclovir tablets on human female fertility. Aciclovir tablets have been shown to have no definite effect upon sperm count, morphology or motility in man. See Clinical Studies in section 5.2. Use of the cream should be considered only when the potential benefit outweighs the possibility of unknown risks however the systemic exposure to aciclovir from topical application of aciclovir cream is very low.

Lipsore 5%

Start using the cream at the first sign of infection (for instance, when you first feel your skin tingling) and continue to use it for five days. This is often sufficient time for the sore to heal but you can continue to use the cream for a further five days if needed. Remember to wash and dry your hands before and after using aciclovir, to prevent spreading any infection. Apply a thin layer of the cream to the infected area and the skin immediately next to it, 5 times a day at intervals of about 4 hours. Take care not to rub the infected skin any more than you need to. 3. Wash your hands again, to avoid spreading the infection. Lipsore 5% w/w cream contains cetyl alcohol and propylene glycol which may cause local skin reactions (skin irritation and redness). Type 1 herpes simplex virus is the usual cause of cold sores around the mouth. It also causes up to half of the cases of genital herpes.