Pubic Hair Growth

[Guest Mellissa]

My one year old son has been on Phenobarbital his entire life and has recently developed pubic hair, has anyone else heard of this? Our Pediatrician told us the medication caused premature growth, but we are still sceptical.

[edited topic description to amplify. a.m.]

[Mellissa]

Anyone out there ever heard that Phenobarbital causes pubic hair growth? Seeing pubic hair on a one year olds scrotum is slightly disturbing.

[Merged cross posts. a.m.]

[AirMarshall]

I am unable to find anything reliable that substantiates phenobarbital causing premature pubic hair growth. I found an unanswered question posted by a social worker who was assisting an 18month old who had been treated for post shaken baby seizures with PHB, who was showing "signs of puberty". Also a family blog about a 7yo girl with uncontrolled seizures being treated with PHB who was suspected of precocious puberty. Neither is reliable, since in the former we don't have complete and reliable medical info, and in the latter, 7yo is quite early, but not unheard of.

Drug interactions

Metabolism of PHB is inhibited by PHT, valproate, felbamate, and dextropropoxyphene. Enzyme inducers, such as rifampin, decrease PHB levels. Because of the potent induction of the hepatic enzymes, PHB increases the metabolism of estrogen, steroids, warfarin, CBZ, diazepam, clonazepam, and valproate. Its effect on PHT is unpredictable. Quotes taken from eMedicine: http://www.emedicine.com/neuro/topic692.htm

It is well established that PHB causes the liver to metabolize or break down chemicals and hormones much faster than normal. Since estrogen and steroids (including cortisol) are specifically mentioned, I would expect that if anything, it would retard the development of secondary sexual characteristics.

Adverse effects and toxicity

The most important adverse effects are cognitive and behavior alterations. Children are more likely than adults to exhibit behavioral changes (ie, paradoxical hyperkinesis). Sedation is prominent, particularly at the beginning of therapy, and usually subsides. Psychomotor slowing, poor concentration, depression, irritability, ataxia, and decreased libido are other effects. Long-term use of PHB may be associated with coarsening of facial features, osteomalacia, and Dupuytren contractures. Folate deficiency, megaloblastic anemia, and idiosyncratic skin reaction are rare. Vitamin supplementation is warranted. Hepatitis has been reported secondary to an immune-mediated process.

No mention is made of any such side effect.

While PHB is no longer a front line med, from my reading, it is still used for pregnant women with epilepsy and in newborn and infants. There should be some level of experience among doctors using this med. The real expert would be an endocrinologist. Hormonal changes associated with puberty have major implications for the body. You may want to seriously consider an endocrinology consult. An endocrinologist should have a better idea of effects and outcomes, and could order blood tests that would provide definitive answers as to what is going on.

Good luck with both conditions. a.m.

[Caillech]

Ok