Neuromuscular Adverse Effects Associated with Systemic Retinoid Dermatotherapy

Abstract

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.

Evaluation of Retinal Nerve Fiber Layer Changes with Oral Isotretinoin Treatment

“…Previous reports have suggested a causal association between oral isotretinoin and acquired central nervous system (CNS) neurotoxicity and neuropathy [5–7]. 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 [5–7].…”

“…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 [5–7]. A single case of optic swelling associated with isotretinoin has also been reported [8].…”

Presumed Isotretinoin-Induced, Concomitant Autoimmune Thyroid Disease and Ocular Myasthenia Gravis: A Case Report

“…Among the many adverse effects of isotretinoin, eye dryness, corneal and retinal abnormalities, myalgia, true myopathy, psychiatric problems, and several autoimmune disorders have been described [2, 3, 4, 5, 6, 7, 8]. A literature review has revealed very few case reports of autoimmune disorders associated with isotretinoin intake.…”

Identification of Retinoic Acid in a High Content Screen for Agents that Overcome the Anti-Myogenic Effect of TGF-Beta-1

“…Also, it is important to note that there also are well-known adverse effects of using retinoids in humans. The two most commonly prescribed oral retinoids, isotretinoin and acitretin, are associated with generalized muscle stiffness syndrome and myalgia in some individuals [93]. Other adverse effects of oral retinoids include dryness of mucous membranes and eyes, increase in serum triglycerides and teratogenicity [94].…”