Isotretinoin therapy has furthermore proven effective against genital warts in experimental use, but is rarely used for this indication as there are more effective treatments. Isotretinoin may represent an efficacious and safe alternative systemic form of therapy for recalcitrant condylomata acuminata (RCA) of the cervix. In most countries this therapy is currently unapproved and only used if other therapies failed. Prescribing restrictions
Isotretinoin is a teratogen; there is about a 20–35% risk for congenital defects in infants exposed to the drug in utero, and about 30–60% of children exposed to isotretinoin prenatally have been reported to show neurocognitive impairment. Because of this, there are strict controls on prescribing isotretinoin to women who may become pregnant and women who become pregnant while taking isotretinoin are strongly advised to terminate their pregnancies.In most countries, isotretinoin can only be prescribed by dermatologists or specialist physicians; some countries also allow limited prescription by general practitioners and family doctors. In the United Kingdom and Australia, isotretinoin may be prescribed only by or under the supervision of a consultant dermatologist. Because severe cystic acne has the potential to cause permanent scarring over a short period, restrictions on its more immediate availability have proved contentious. In New Zealand, isotretinoin can be prescribed by any doctor but subsidised only when prescribed by a vocationally-registered general practitioner, dermatologist or nurse practitioner.In the United States, since March 2006 the dispensing of isotretinoin is run through a website called iPLEDGE.
The drug is associated with inflammatory bowel disease (IBD)—ulcerative colitis, but not Crohns disease. There are also reports of people developing irritable bowel syndrome (IBS) and worsening of existing IBS. Eyes
Isotretinoin and other retinoids are well known to affect the eyes. Dry eyes are very common during treatment and is caused by isotretinoins apoptotic effect on the meibomian glands. Some people develop contact lens intolerance as a result. In some people, these changes are long-lasting or irreversible and represent Meibomian Gland Dysfunction (MGD). Other common effects on the eyes include inflammation of the eyelid (blepharitis), red eye caused by conjunctivitis and irritation of the eye. More rare ocular side effects include blurred vision, decreased night vision (which may be permanent), colour blindness, development of corneal opacities, inflammation of the cornea (keratitis), swelling of the optic disk (papilloedema, associated with IIH), photophobia and other visual disturbances. Pharmacology
Mechanism of action
Isotretinoins exact mechanism of action is unknown, but several studies have shown that isotretinoin induces apoptosis (programmatic cell death) in various cells in the body. Cell death may be instigated in the meibomian glands, hypothalamic cells, hippocampus cells and—important for treatment of acne—in sebaceous gland cells.