Sir,
I congratulate the authors of this study.1 It is, to my knowledge, the first published study on the real world experience of patients receiving generic versions of latanoprost available in the UK.
The results relating to patient preference and desire to recommence branded medication are as expected. Patients in the study, as many patients with ocular hypertension and primary open angle glaucoma, are subject to variables associated with non-acceptance of generic medication, namely, being elderly and having had their medicine originally prescribed by a hospital specialist.2
Patients concerned about wasting of resources can be reassured. The cost of using generic latanoprost at the April 2014 price of £1.77 per 2.5 ml (Department of Health Drug Tariff, available at http://www.ppa.org.uk/ppa/edt_intro.htm), is substantially less than that of using Xalatan at £12.48 per 2.5 ml (http://www.mims.co.uk/Drugs/eye/glaucoma/xalatan/) even if the patients need more than one bottle per month. Patients who are supported in the change—for example, by counselling and the provision of suitable dispensing aids—are more likely to adjust successfully.
I note that the study was undertaken before the introduction of the new formulation of Xalatan in March 2013 (http://www.medicines.org.uk/emc/medicine/9043/SPC/). The lower pH of the Xalatan available since that date may alter the results relating to comfort in the eye as Xalatan is now the most acidic latanoprost eye drop on the UK market.
It would be of interest to know whether loss of control of IOP in individuals using generic latanoprost was associated with non-compliance due to problems in administration of the medication or with the use of specific generics. Patients and those involved in their care should be encouraged to report problems with generic latanoprost to the MHRA via the Yellow Card scheme giving details of the generic concerned.
The author declares no conflict of interest.
References
- Painter SL, Mead AL. Patient experience of the transition from Xalatan to generic latanoprost. Eye. 2014;28 (7:911. doi: 10.1038/eye.2014.71. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sagardui-Villamor JK, Lacalle Rodríguez-Labajo M, Casado-Buendía S. Substitution of generic for brand medicines in primary care. Factors associated to refuse the change. Aten Primaria. 2005;36 (9:489–493. doi: 10.1016/S0212-6567(05)70550-3. [DOI] [PMC free article] [PubMed] [Google Scholar]