Peripheral sensory neuropathy associated with short-term oral acitretin therapy

Neurological and Neuropsychiatric Adverse Effects of Dermatologic Medications

Severe, recalcitrant dermatologic conditions often require systemic treatment. Although efficacious, these medications have been associated with wide-ranging adverse reactions. Some are reversible, predictable, and either dose-dependent or treatment length-dependent, while others are unpredictable, irreversible, and potentially fatal. This review examines the neuropsychiatric adverse effects associated with US FDA-approved medications for treatment of the following dermatologic pathologies that typically require systemic therapy: autoimmune dermatoses, acne, psoriasis, and melanoma. A search of the literature was performed, with adverse effects ranging from mild headaches and neuropathy to severe encephalopathies. The medications associated with the most serious reactions were those used to treat psoriasis, especially the older non-biologic medications such as cyclosporine A and methotrexate. Given the importance of these systemic dermatologic therapies in treating severe, recalcitrant conditions, and the wide variety of potentially serious neuropsychiatric adverse effects of these medications, neurologists, psychiatrists, dermatologists, oncologists, and primary care providers must be aware of the potential for these neuropsychiatric adverse reactions to allow for appropriate counseling, management, and medication withdrawal.

Effect of Oral Isotretinoin Treatment on Retinal Nerve Fiber Layer Thickness

Background:

Oral isotretinoin treatment can cause ocular side effects.

Objective:

This study was performed to detect possible toxic effects of oral isotretinoin treatment on the retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL).

Methods:

The study population consisted of 54 eyes of 27 patients with nodulocystic acne who used oral isotretinoin (Roaccutane) treatment. Macular GCL and peripapillary RNFL thickness measurements were performed using spectral domain optical coherence tomography (OCT) before and after therapy.

Results:

Before and after treatment, a complete ophthalmologic examination was normal in all eyes. However, posttreatment lower temporal (TL) values were significantly lower (76.80 ± 16.31) than pretreatment TL values (84.96 ± 24.83) ( p = .02). There was no statistically significant difference in the other OCT values, upper temporal, superotemporal, superonasal, upper nasal, lower nasal, inferonasal, and inferotemporal ( p = .35, p = .40, p = .56, p = .95, p = .94, p = .93, p = .61, respectively). Also, there was no statistically significant difference between the right and left eyes and between genders for all parameters ( p > .05).

Conclusion:

The use of oral isotretinoin treatment has increased in recent years. In addition, oral isotretinoin treatment has a broad adverse effect potential on the ocular system. The measurement of RNFL thickness, especially TL thickness, by OCT may be useful for detecting the possible toxic effect of oral isotretinoin therapy on RNFL.

Neuromuscular adverse effects associated with systemic retinoid dermatotherapy: monitoring and treatment algorithm for clinicians

Although neuromuscular adverse effects represent significant clinical manifestations of hypervitaminosis A syndrome, surprisingly little attention has been paid to the potential neuromuscular toxicity of vitamin A derivatives (retinoids). Since isotretinoin and acitretin are currently the two most commonly used oral retinoids in systemic dermatotherapy, this review focuses exclusively on their neuromuscular adverse effects and proposes a neuromuscular algorithm for appropriate monitoring of patients treated with these two compounds. The most frequent CNS adverse effect associated with oral isotretinoin is headache, either as an independent adverse effect or as part of benign intracranial hypertension, which is additionally characterized by nausea and visual changes. Isolated cases of stiff-person-like syndrome, epileptic seizures and generalized muscle stiffness syndrome, possibly or probably related to oral treatment with isotretinoin, have also been reported. In addition, oral isotretinoin has reportedly been associated with muscular adverse effects that most frequently manifest as myalgia and stiffness and, in rare cases, as true myopathy or rhabdomyolysis. Creatine phosphokinase, a specific marker of muscle destruction, has been found to be elevated, occasionally by up to 100 times the normal value (with or without muscular symptoms and signs), in a variable percentage of patients receiving isotretinoin treatment and particularly in those undergoing vigorous physical exercise. Oral acitretin has been found to cause peripheral nerve dysfunction, particularly of sensory fibres, which in rare cases leads to clinically evident sensory disturbances. Less clear is the causal relationship between acitretin and benign intracranial hypertension or myopathy, whereas an isolated case of cranial nerve IV (oculomotor) palsy and a further case of thrombotic stroke during treatment with oral acitretin have been reported. Systemic diseases with involvement of nervous and/or muscle tissue and neuromuscular disorders should be regarded as exclusion criteria for initiation of oral retinoid therapy. Additionally, intense physical exercise and concurrent treatment with neurotoxic or myotoxic drugs should be avoided during treatment with oral retinoids. In order to minimize the potential risk of neuromuscular adverse effects, a neuromuscular algorithm is suggested that may be useful for monitoring patients taking oral retinoids.

Peripheral large nerve fibre function in patients with chronic plaque psoriasis

Accumulating evidence suggests the involvement of neurogenic inflammation in the pathogenesis of psoriasis. Moreover, the concomitant occurrence of peripheral neuropathy has been reported in several psoriatic patients. Thus, the aim of the present study was to answer the question whether an impairment of peripheral large nerve fibre function may exist in psoriasis. Thirty-two patients with severe and generalized chronic plaque psoriasis and 32 sex- and age-matched healthy controls were evaluated by detailed clinical neurological and standard neurophysiological examination. The latter included motor nerve conduction study of one nerve in the upper and one in the lower extremities and sensory nerve conduction study of one nerve in the upper and two in the lower extremities. Neurological examination failed to demonstrate any clinical evidence of large fibre neuropathy. Furthermore, all values of the examined neurophysiological parameters were within normal limits; comparisons of the corresponding mean values in the patient and the control group showed no statistically significant differences. These findings demonstrate no measurable abnormalities of the peripheral large nerve fibres in psoriatic patients and therefore an association of psoriasis with peripheral large fibre neuropathy cannot be suggested.

Effects of oral isotretinoin therapy on peripheral nerve functions: a preliminary study

Accumulating evidence over the past decade indicates that synthetic retinoids may be capable of affecting both growth and differentiation of nervous tissue. Our aim was to substantiate possible side-effects of oral isotretinoin therapy on peripheral nerve functions, both neurologically and neurophysiologically. We performed neurological examination and electroneuromyographic studies on 18 patients with various skin diseases before, at the third month, and at the end of isotretinoin treatment. Abnormal neurophysiological findings in this study point towards a typical distal, length-dependent and predominantly sensory polyneuropathy. Clinicians should be aware of possible neurological sensorial symptoms during isotretinoin therapy. In our opinion, electroneuromyographic investigation should be performed on all patients reporting symptoms (e.g. paresthesia, numbness, sensory loss) before and during oral isotretinoin treatment. The precise clinical significance of the isotretinoin-induced neurophysiological alterations reported here remains to be determined in further studies.

Short-term oral isotretinoin therapy does not cause clinical or subclinical peripheral neuropathy

BACKGROUND

Subclinical neurophysiologic abnormalities mainly suggestive of sensory fibers dysfunction were observed in some patients after 1 and 3 months of treatment with oral acitretin. Moreover, two cases of peripheral sensory neuropathy and one of sensorimotor polyneuropathy were observed after short-term oral administration of this compound.

OBJECTIVE

The objective of this prospective study was to investigate whether short-term treatment with oral isotretinoin can also affect peripheral nerve function.

METHODS

Serial neurologic and neurophysiologic examinations were performed on 18 young patients with severe nodulocystic acne prior to and 1 and 3 months after the onset of oral isotretinoin treatment (1 mg/kg per day).

RESULTS

Clinical neurologic examination before and under treatment disclosed no abnormalities in any of the patients. There were no significant differences between the pre- and post-treatment neurophysiologic parameters. Furthermore, evaluation of the serial neurophysiologic measurements in each patient separately under oral isotretinoin treatment revealed no changes fulfilling the criteria of abnormality.

CONCLUSIONS

Short-term administration of oral isotretinoin in young patients does not cause clinical or subclinical neuropathy.