(See also boxed CONTRAINDICATIONS AND WARNINGS)

Skeletal Abnormalities

In adults receiving long-term treatment with acitretin, appropriate examinations should be periodically performed in view of possible ossification abnormalities (see ADVERSE REACTIONS). Because the frequency and severity of iatrogenic bony abnormality in adults is low, periodic radiography is only warranted in the presence of symptoms or long-term use of acitretin. If such disorders arise, the continuation of therapy should be discussed with the patient on the basis of a careful risk/benefit analysis. In clinical trials with acitretin, subjects were prospectively evaluated for evidence of development or change in bony abnormalities of the vertebral column, knees, and ankles.

Of 380 subjects treated with acitretin, 15% had preexisting abnormalities of the spine which showed new changes or progression of preexisting findings. Changes included degenerative spurs, anterior bridging of spinal vertebrae, diffuse idiopathic skeletal hyperostosis, ligament calcification, and narrowing and destruction of a cervical disc space. De novo changes (formation of small spurs) were seen in 3 subjects after 1½ to 2½ years.

Six of 128 subjects treated with acitretin showed abnormalities in the knees and ankles before treatment that progressed during treatment. In 5, these changes involved the formation of additional spurs or enlargement of existing spurs. The sixth subject had degenerative joint disease which worsened. No subjects developed spurs de novo. Clinical complaints did not predict radiographic changes.

Lipids and Possible Cardiovascular Effects

Blood lipid determinations should be performed before acitretin is administered and again at intervals of 1 to 2 weeks until the lipid response to the drug is established, usually within 4 to 8 weeks. In subjects receiving acitretin during clinical trials, 66% and 33% experienced elevation in triglycerides and cholesterol, respectively. Decreased high density lipoproteins (HDL) occurred in 40% of subjects. These effects of acitretin were generally reversible upon cessation of therapy.

Subjects with an increased tendency to develop hypertriglyceridemia included those with disturbances of lipid metabolism, diabetes mellitus, obesity, increased alcohol intake, or a familial history of these conditions. Because of the risk of hypertriglyceridemia, serum lipids must be more closely monitored in high-risk patients and during long-term treatment.

Hypertriglyceridemia and lowered HDL may increase a patient’s cardiovascular risk status. Although no causal relationship has been established, there have been postmarketing reports of acute myocardial infarction or thromboembolic events in patients on therapy with acitretin. In addition, elevation of serum triglycerides to greater than 800 mg per dL has been associated with fatal fulminant pancreatitis. Therefore, dietary modifications, reduction in dose of acitretin, or drug therapy should be employed to control significant elevations of triglycerides. If, despite these measures, hypertriglyceridemia and low HDL levels persist, the discontinuation of acitretin should be considered.

Ophthalmologic Effects

The eyes and vision of 329 subjects treated with acitretin were examined by ophthalmologists. The findings included dry eyes (23%), irritation of eyes (9%), and brow and lash loss (5%). The following were reported in less than 5% of subjects: Bell’s palsy, blepharitis and/or crusting of lids, blurred vision, conjunctivitis, corneal epithelial abnormality, cortical cataract, decreased night vision, diplopia, itchy eyes or eyelids, nuclear cataract, pannus, papilledema, photophobia, posterior subcapsular cataract, recurrent sties, and subepithelial corneal lesions.

Any patient treated with acitretin who is experiencing visual difficulties should discontinue the drug and undergo ophthalmologic evaluation.

Pancreatitis

Lipid elevations occur in 25% to 50% of subjects treated with acitretin. Triglyceride increases sufficient to be associated with pancreatitis are much less common, although fatal fulminant pancreatitis has been reported. There have been rare reports of pancreatitis during therapy with acitretin in the absence of hypertriglyceridemia.

Pseudotumor Cerebri

Acitretin and other retinoids administered orally have been associated with cases of pseudotumor cerebri (benign intracranial hypertension). Some of these events involved concomitant use of isotretinoin and tetracyclines. However, the event seen in a single patient receiving acitretin was not associated with tetracycline use. Early signs and symptoms include papilledema, headache, nausea and vomiting, and visual disturbances. Patients with these signs and symptoms should be examined for papilledema and, if present, should discontinue acitretin immediately and be referred for neurological evaluation and care. Since both acitretin and tetracyclines can cause increased intracranial pressure, their combined use is contraindicated (see CONTRAINDICATIONS).

Capillary Leak Syndrome

Capillary leak syndrome, a potential manifestation of retinoic acid syndrome, has been reported in patients receiving acitretin. Features of this syndrome may include localized or generalized edema with secondary weight gain, fever, and hypotension. Rhabdomyolysis and myalgias have been reported in association with capillary leak syndrome, and laboratory tests may reveal neutrophilia, hypoalbuminemia, and an elevated hematocrit. Discontinue acitretin if capillary leak syndrome develops during therapy.

Exfoliative Dermatitis/Erythroderma

Exfoliative dermatitis/erythroderma has been reported in patients receiving acitretin. Discontinue acitretin if exfoliative dermatitis/erythroderma occurs during therapy.