Chloroquine myopathy.

Abstract

Chloroquine (7-chloro-4(4-diethylamino-1-methylbutylamino)quinoline) is one of the more effective and less toxic of the quinoline derivatives that were introduced as antimalarials during and after World War II (Grollman, 1965). It also proved useful in the treatment of amoebiasis, in rheumatoid arthritis, and in certain skin diseases. With the long-term ingestion of the drug a number of side effects appeared, perhaps the most serious of which were those involving the eye, with reversible corneal (Calkins, 1958) and irreversible macular changes (Hobbs, Sorsby, and Freedman, 1959;Ormrod, 1962). Since 1963 there have been occasional suggestions that chloroquine may also injure peripheral nerve and muscle. There are still only a few descriptions of such chloroquine neuropathy or myopathy, and in several of these the drug was used in treating patients with possible or proven collagen diseases. In these latter instances the cause of the muscle change is perhaps open to some doubt, as the histological finding that is probably characteristic of chloroquine toxicity to muscle, a vacuolar myopathy, also occurs in systemic lupus erythematosus (Pearson, 1964).Because the condition is rare, is potentially reversible, and possibly not well known, it has seemed worth recording a further instance of vacuolar myopathy due to chloroquine, particularly when this occurred in a patient in whom there was no question of underlying collagen disease. CASE REPORTA 54-year-old mother of two children presented with a two-year history of recurrent cystitis. She In both (a) and (b) the time trace covers 300 msec. and its peak to peak amplitude is 300 microvolts.ELECTROMYOGRAPHY At electromyography insertion activity was normal in the muscles sampled. There was no spontaneous activity. The interference pattern on maximum voluntary contraction was normal in the right abductor pollicis brevis and left extensor digitorum brevis. Motor units were of decreased amplitude and duration in the right biceps brachii, and in right and left deltoids and quadriceps. There was an increased proportion of polyphasic units in the left deltoid and both tibialis anterior muscles (Fig. 1). In the left quadriceps there was some loss of motor units, and in the right quadriceps some long duration units (up to 10 msec.). The appearances suggested a pritnary muscle disorder, though there was some suggestion of denervation, particularly in the quadriceps.In the right forearm the maximum motor conduction velocity in the median nerve, measured with a coaxial needle electrode in the abductor pollicis brevis, according to the technique described by Thomas, Sears, and Gilliatt (1959), was 59 m./sec. (normal range 52-67 m./sec.). The terminal latency was normal (4 msec.). Spindle afferent mean conduction velocity in the right median nerve in the forearm, measured with H reflex latencies according to the principles described by Angel and Alston (1964), was 47 m./sec. The maximum motor conduction velocity in the left lateral popliteal nerve, measured to a needle electrode i...

Hydroxychloroquine‐induced autophagic vacuolar myopathy with mitochondrial abnormalities

“…Both HCQ and chloroquine are also known to have significant lysosomal affinity . Long‐term administration leads to deposition in tissues including muscles, nerves and retina, and has been linked in skeletal muscle to vacuolar myopathy and curvilinear body formation . Although HCQ is thought to be less toxic, its use has also been reported in cases of severe myopathy leading to hospitalization and need for ventilatory support …”

“…7 Long-term administration leads to deposition in tissues including muscles, nerves and retina, and has been linked in skeletal muscle to vacuolar myopathy and curvilinear body formation. [8][9][10][11][12][13] Although HCQ is thought to be less toxic, its use has also been reported in cases of severe myopathy leading to hospitalization and need for ventilatory support. 14,15 We report biopsy findings in four patients on chronic use of HCQ with histories of long-term autoimmune disorders.…”

An appraisal of chloroquine

“…The mechanism of myasthenia is not known, but it may occur without microscopic abnormalities. The contractile mechanism (68) appears to be inhibited to a greater extent than the myoneural junction (66). Perhaps the mitochondria1 metabolism is suppressed (65), or the glycolytic enzymes inhibited (66).…”

“…The contractile mechanism (68) appears to be inhibited to a greater extent than the myoneural junction (66). Perhaps the mitochondria1 metabolism is suppressed (65), or the glycolytic enzymes inhibited (66). Although motor and afferent nerve conduction studies have been normal during myasthenia in most patients, some electromyographic evidence for neuropathy has been reported (52, 66, 69).…”

Vacuolar Myopathies: Ultrastructural Studies Benefit Diagnosis

“…Chloroquine is a drug first used as an antimalarial, and later found to be effective also in treating rheumatoid arthritis, systemic lupus erythematosis, and other diseases [6]. Its method of action is to raise intralysosomal pH and thereby inhibit lysosomal enzymes [7].…”