[AF] Varón con leflunomida y embarazo

[Ramon Diaz-Alersi]

Menuda papeleta. Y un poco bruto ese médico, si ha actuado como dices pasando de diagnóstico perinatal y demás...
Por lo que he visto, el riesgo de teratogénesis no es muy elevado y la clasificación de X de la FDA se basa en estudios en roedores. Que yo sepa (quizás se me haya escapado algún caso en mi revisión), no se han descrito todavía casos de malformaciones en humanos, aunque, claro, una gran proporción de las embarazadas deciden abortar. No he encontrado  datos sobre el efecto cuando el que lo toma es el padre, aunque teóricamente, existe.
  
Hay una revisión en castellano de 2005, que me parece que te puede aclarar algo las ideas:

http://www.grupoaran.com/mrmUpdate/lecturaPDFfromXML.asp?IdArt=457457&TO=RVN&Eng=0
  
Las conclusiones de este otro artículo, de 2006, son muy semejantes:

Human pregnancy safety for agents used to treat rheumatoid arthritis:  adequacy of available information and strategies for developing  post-marketing data:

Leflunomide

The largest series of peer-reviewed published data available regarding the prenatal effects of leflunomide in humans is from a questionnaire mailed to rheumatologists regarding their practices when prescribing DMARDs. In this summary of retrospectively reported pregnancies with no comparison group, there were no malformations reported among the offspring of 10 women who were prescribed leflunomide during pregnancy. An additional three case reports of women with first trimester exposure to leflunomide were reported by an Italian Teratology Information Service. Two of these pregnancies ended in voluntary termination and the third in a normal live birth. Another 43 pregnancy outcomes with first-trimester exposure to leflunomide have been published in abstract. In an ongoing prospective controlled study of RA medications in pregnancy being conducted by the North American Organization of Teratology Information Specialists, 43 leflunomide-exposed women were compared to 78 women with RA who did not use leflunomide and a second group of 47 women without RA. Based on very small numbers, rates of major birth defects were similar between the groups. Infants exposed to leflunomide were significantly more likely than non-diseased comparison infants to be born prematurely and were significantly smaller in birth weight. However, there were no significant differences on these two measures between the leflunomide-exposed group and the RA comparison group, suggesting that the underlying disease and/or other medications used to treat RA are likely related to these adverse outcomes.
  Despite the minimal data in humans, leflunomide has been assigned an FDA pregnancy category X. This is based on its mechanism of action (interference with DNA and RNA synthesis), as well as animal studies in pregnant rats and rabbits that demonstrated an increased risk for congenital malformations in their offspring. However, based on a lack of adequate data in human pregnancy, at the present time, the teratogenic risk of leflunomide is unknown.
  
El artículo completo está disponible aquí:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1779429/?tool=pubmed

Aunque el único párrafo de interés es el que he transcrito. 
  
Saludos.

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Ramón Díaz-Alersi