Differences in phototoxic potency should be considered when tetracyclines are prescribed during summer-time. A study on doxycycline and lymecycline in human volunteers, using an objective method for recording erythema

Abstract

In order to test the phototoxic potency of the two tetracyclines most frequently prescribed in Sweden, a double-blind cross-over study using a double-dummy technique with doxycycline 0.1 g twice daily, lymecycline 0.6 g twice daily, and placebo, was performed in 15 healthy volunteers. Drugs were given for 3 consecutive days, and on the third day volunteers were tested with 25, 50, 75 and 100 J/cm2 of artificial long-wave ultraviolet radiation (UVA), and assessed 6 h later for erythematous photoreactions. Objective readings were made using skin reflectance spectrophotometry. All three substances were tested in each individual at weekly intervals. Within 50, 75 and 100 J/cm2 of UVA, lymecycline showed a slight increase in erythema compared with placebo, but this was not significant (50 and 100 J/cm2), or was of low significance (75 J/cm2). However, with the same doses, doxycycline showed a substantial increase in erythema compared with placebo, which was highly significant. We conclude that doxycycline has a higher phototoxic potency than lymecycline, and this is in agreement with earlier in vitro experimental data. We recommend that therapy with doxycycline is avoided during summer-time, and during holidays in a sunny climate.

Phototoxicity of Doxycycline: A Systematic Review on Clinical Manifestations, Frequency, Cofactors, and Prevention

“…The information gathered is derived mainly from case reports, while there are only few studies. The quality of evidence differs in that there are double-blind cross-over studies [14] as well as case reports with rechallenge [19] and mere case reports [3], as shown in Table 1. The low number of reports on doxycycline phototoxicity may be interpreted in 2 ways: either a true low incidence of events or serious underreporting.…”

“…The main spectrum of wavelength causing phototoxic reactions seems to be UVA1 (340-400 nm) [13,14] while the minimal dose of UV light, being able to provoke a significant increase of erythema reaction compared to placebo, seems to be around 50 J/cm 2 (investigated doses were 25, 50, 75, and 100 J/cm 2 , whereas no significant increase of erythema reaction was found at 25 J/cm 2 ) as detected by Bjellerup and Ljunggren [14] using a UVA system emitting mainly between 345 and 445 nm, with a peak at 370 nm. Nevertheless, doxycycline may also lead to a reduction of the minimal erythema dose in the spectrum of UVB [4].…”

Nouvelles de l’industrie / Neues aus der Industrie

“…Le «prodrug lymecyclinum» a été déve-loppé dans le but d'améliorer l'absorption et la tolérance. De plus, Tétralysal 300 se caractérise par son faible potentiel phototoxique [6].…”

Evolution of a Doxycycline-Induced Phototoxic Rash With an Unusual Distribution

“…7 Phototoxic eruptions, however, are thought to be due to radiation in the UVA1 spectrum of 340-400 nm. 8 Zinc oxide may be a better choice of sunscreen as it is the only sunscreen that offers protection against UVB and UVA radiation up to 400 nm. 7 Limited data exists on dermatologists' recommendations regarding sunscreen as well as patient perception and compliance.…”