Prescribing lessons from an ocular chemical injury: Vitaros inadvertently dispensed instead of VitA-POS

Abstract

We wish to report an ocular chemical injury caused by inadvertent dispensing and administration of an erectile dysfunction cream (Vitaros) instead of an ocular lubricant (VitA-POS) to highlight this potential source of error. Prescribing errors are common, and medications with similar names/packaging increase risk. However, it is unusual in this case that no individual (including the patient, general practitioner or dispensing pharmacist) questioned erectile dysfunction cream being prescribed to a female patient, with ocular application instructions. The patient was treated for a mild ocular chemical injury with topical antibiotics, steroids and lubricants, with good response. However, we believe this to be an important issue to report to enhance awareness and promote safe prescribing skills.

Background

Prescribing errors are common, affecting 1 in 20 prescriptions, according to the GMC 2012 PRevalence And Causes of prescribing errors in general practiCe (PRACtICe) Study.^{1 2} Risk factors include polypharmacy, age, and medication genre (implicating ocular disorders).^{1 2} Medications with similar names/packaging further increase risk. We wish to report an ocular chemical injury caused by inadvertent dispensing and administration of an erectile dysfunction cream (Vitaros) instead of an ocular lubricant (VitA-POS) to highlight this potential source of error.

Case presentation

A female patient from another hospital was given a handwritten prescription for VitA-POS (liquid paraffin lubrication (Scope Ophthalmics)) for treatment of severe dry eyes and recurrent corneal erosions. Unfortunately, between her general practitioner (GP) and pharmacist, she was issued with Vitaros (an erectile dysfunction cream (Takeda)) (see figure 1). Ocular application resulted in immediate symptoms of discomfort and blurred vision, as well as redness and lid swelling. She immediately irrigated the eye, and on emergency review was found to have conjunctival injection, mild anterior chamber activity and small epithelial defect but no limbal ischaemia.

Figure 1.

Photograph comparing packages of VitA-POS and Vitaros.

Outcome and follow-up

The patient was treated for a mild ocular chemical injury with topical antibiotics, steroids and lubricants, with good response. While the chemical injury resolved within a few days, the patient has continued to suffer from recurrent corneal erosions and has had botulinum toxin ptosis to help protect her ocular surface in addition to Ikervis and regular lubricants.

Discussion

The PRACtICe Study cited multifactorial causes for prescribing errors, including time pressure, illegible handwriting and computer-associated such as drop-down lists.^{1 2} While the packages of Vitaros and VitA-POS cream are different (figure 1), a first-time user might have difficulty in differentiating them due to a single letter difference in brand name. However, it is unusual in this case that no individual (including the patient, GP or dispensing pharmacist) questioned erectile dysfunction cream being prescribed to a female patient, with ocular application instructions.

A literature search did not reveal any documented cases of ocular injury due to Vitaros. Vitaros contains the active ingredient alprostadil, hydroxypropyl guar and various excipients for pH adjustment, including ethanol, sodium hydroxide and phosphoric acid. We were unable to identify the pH of Vitaros in the published literature, but testing of a sample with litmus paper revealed a pH of 5–6. The mechanism of ocular injury is therefore most likely a mild chemical injury similar to reports from e-cigarette fluid, nail glue and olbas oil, except in this case, the patient expected to receive a medical product to use in the eyes.^3–5 However, it was also noted that a much greater degree of force was required to expel the contents of the Vitaros device than what would typically be required for using eye-drops. Accordingly, it is possible that a mechanical abrasion could have occurred as well.

We would like to raise awareness that medications with similar spellings exist. We encourage prescribers to ensure that handwritten prescriptions are printed in block capital letters (including the hyphen with VitA-POS) to avoid similar scenarios in the future.

Learning points.

• Prescribing errors are common, and medications with similar names/packaging increase risk.

• Medications not licenced for ocular use can result in varying degrees of chemical injury.

• We encourage prescribers to ensure that handwritten prescriptions are printed in block capital letters (including the hyphen with VitA-POS) to avoid similar scenarios in the future.