GlaxoSmithKline has announced that they have discontinued Zovirax® (aciclovir) 3% eye ointment.

The decision to discontinue the product has been made following ongoing difficulties in guaranteeing a sustained supply of the product. Current supplies of the eye ointment are anticipated to be available until the end of June 2019.

Zovirax® eye ointment is licensed for the treatment of herpes simplex keratitis. There are no other suppliers of aciclovir 3% eye ointment consequently pharmacists may be asked to suggest alternate treatment options once supplies of Zovirax® run out.

Alternative management options

There are two options that could be used as alternatives to Zovirax® 3% eye ointment

• Ganciclovir 0.15% w/w eye gel
• Trifluorothymidine (trifluridine, TF3) 1% eye drops

First line option: Ganciclovir 0.15% w/w eye gel (Virgan®)

Ganciclovir eye gel is licensed for the treatment of acute herpetic keratitis (dendritic and geographic ulcers).

The manufacturer (Thea Pharmaceuticals Ltd) advises that one drop of the gel is used in the inferior conjunctival sac five times a day until complete corneal re-epithelialisation occurs, followed by three doses a day for 7 days after healing. The full treatment course does not usually exceed 21 days.

Ganciclovir eye ointment contains benzalkonium chloride, which is not an excipient in Zovirax® eye ointment, pharmacists should be alert to patients who may have a sensitivity to this preservative.

Second line option: Trifluorothymidine (trifluridine, FT3) 1% eye drops

In the UK, trifluorothymidine 1% is only available as an unlicensed special from Stockport Pharmaceuticals. Trifluorothymidine eye drops also contain the preservative benzalkonium chloride. Unlike aciclovir eye ointment or ganciclovir eye gel trifluorothymidine eye drops require refrigeration.

A licensed trifluorothymidine eye drop is available in the US. Viroptic® is licensed for the treatment of primary keratoconjunctivitis and also recurrent epithelial keratitis resulting from herpes simplex virus, types 1 and 2. Viroptic® requires refrigeration.

One drop of Viroptic® is instilled into the affected eye every two hours during waking hours to a maximum daily dose of 9 drops until the corneal ulcer has re-epithelialised. Treatment should be continued for an additional 7 days at a dose of one drop every four hours to a maximum daily dose of 5 drops. Where the treatment is not successful and complete re-epithelialisation occurs an alternate agent should be used as continuous administration for periods exceeding 21 days is not recommended.

Clinical equivalence

A Cochrane review conducted in 2015[1] into the antiviral treatment of epithelial keratitis due to herpes simplex infection concluded that trifluridine and aciclovir are similar in clinical efficacy and ganciclovir is at least as effective as aciclovir.

Wherever possible a UK licensed product, i.e. ganciclovir, should be selected. Where this is unsuitable the advice of a specialist should be sought. As with most unlicensed specials or imported products the cost associated with trifluorothymidine will be greater than ganciclovir.