Some of the views expressed in the following notes on newly approved products should be regarded as preliminary, as there may have been limited published data at the time of publication, and little experience in Australia of their safety or efficacy. However, the Editorial Executive Committee believes that comments made in good faith at an early stage may still be of value. Before new drugs are prescribed, the Committee believes it is important that more detailed information is obtained from the manufacturer's approved product information, a drug information centre or some other appropriate source.


Daivonex (CSL)
ointment containing 50 micrograms/g in 30 g and 100 g tubes
Indication: psoriasis

Psoriasis is a common skin condition which affects at least 1% of the population. The majority of patients have a chronic plaque psoriasis which is amenable to topical therapy.

The pathophysiology of psoriasis involves a proliferation of keratinocytes. This cell proliferation can be suppressed by vitamin D, but the vitamin can also affect calcium metabolism (hypervitaminosis D causes hypercalcaemia). Calcipotriol is a vitamin D derivative which suppresses cell proliferation, but has less effect on calcium metabolism.

Calcipotriol ointment is more effective than placebo. In a 6-week double blind comparison with betamethasone valerate ointment, calcipotriol was more effective at reducing erythema, thickness and scaling.1 Some data exist to suggest that calcipotriol is more effective than short contact dithranol regimens. Calcipotriol is likely to be more cosmetically acceptable than dithranol.

Most of the improvement with calcipotriol treatment occurs in the first two weeks. Some patients who have a good response will relapse, but it is unknown for how long the treatment can be repeated. There is little experience in the use of calcipotriol for more than one year.

It is uncertain how much topical calcipotriol is absorbed through the skin. Although hypercalcaemia has occurred with the recommended twice daily application (up to 100 g a week), most adverse effects occur on the skin. In clinical trials, 23% of patients reported an adverse reaction and 2% had to discontinue therapy. Local reactions include irritation, contact dermatitis, blisters and photosensitivity.

References

  1. Kragballe K, Gjertsen BT, de Hoop D, Karlsmark T, van de Kerkhof PC, Larko O, et al. Doubleblind, right/left comparison of calcipotriol and bethamethasone valerate in treatment of psoriasis vulgaris. Lancet 1991;337:1936.