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.
Neonatal lupus erythematosus is an autoimmune disease in an infant born to a mother with anti-Ro/SSA and with or without anti-La/SSB antibodies. The disease most commonly presents with a rash resembling subacute cutaneous lupus erythematosus and can have systemic abnormalities such as complete heart block or hepatosplenomegaly. Neonatal lupus is usually benign and self-limited. Many of the clinical manifestations are transient, but certain heart problems can be permanent. Diagnosis is based on maternal antibodies and clinical manifestations. Treatment and management is mainly supportive and focused on preventing complete heart block if possible. Pathogenesis
Ro/SSA and La/SSB are proteins found inside cells. Anti-Ro/SSA and anti-La/SSB are antibodies that form against these proteins. These antibodies can be seen in autoimmune diseases, the most common being Lupus and Sjögrens. Mothers can have these antibodies circulating in their blood without having any signs or symptoms of an autoimmune disease. Babies born to mothers with these antibodies have a chance of developing neonatal lupus erythematosus. This occurs when maternal anti-Ro/SSA and anti-La/SSB antibodies enter fetal circulation and affect neonatal organs by crossing the placenta using FcRn receptors. The mechanism in which the antibodies affect organs is not yet completely understood. For the heart, it is thought that these antibodies bind to cells in the heart that go through physiologic cell death during embryogenesis. This leads to heart cell injury which causes secondary fibrosis in the conduction system, ultimately causing heart block. These antibodies can also affect calcium channels which are needed to initiate action potentials.