Muscular weakness and cramp

A 27- year-old male with a three-year history of AIDS complains of progressive blurring of vision for two days. Eye examination reveals evidence of retinitis consistent with cytomegalic virus inclusion disease. Intravenous treatment is started, and within five days the patient complains of muscular weakness and cramping. Blood chemistries show a creatinine of. 5.2 mEq/L and a Ca of 6.9 mEq/L. 

Muscular work is accompanied by the production of ammonia, the immediate source of which is adenosine 5 -phosphate (AMP).301 302 This fact led to the recognition of another substrate cycle (Chapter 11) that functions by virtue of the presence of a biosynthetic pathway and of a degradative enzyme in the same cells (cycle A, Fig. 25-17). This purine nucleotide cycle operates in the brain303 304 as well as in muscle. The key enzyme 5-AMP aminohydrolase (AMP deaminase step a, Fig. 25-17) also occurs in erythrocytes and many other tissues.304 305 Persons having normal erythrocyte levels but an absence of this enzyme in muscles suffer from muscular weakness and cramping after exercise.306... 

Senna may cause abdominal cramps and diarrhoea. Prolonged use of senna may produce watery diarrhoea with excessive loss of fluid and electrolytes, particularly potassium, muscular weakness and weight loss. Changes in the intestinal musculature associated with malabsorption and dilation of the bowel, similar to ulcerative colitis and to megacolon, may also occur. Cardiac and renal symptoms have been reported. Melanosis coli and a red or yellow discoloration of the urine and faeces may also occur. 

Patients with secondary hypertension may complain of symptoms suggestive of the underlying disorder, but some are asymptomatic. Patients with pheochromocytoma may have a history of paroxysmal headaches, sweating, tachycardia, and palpitations. Over half these patients suffer from episodes of orthostatic hypotension. In primary aldosteronism, symptoms related to the hypokalemia usually include muscle cramps and muscle weakness. Patients with Cushing s syndrome may complain of weight gain, polyuria, edema, menstrual irregularities, recurrent acne, or muscular weakness and have several classic physical features (e.g., moon face, buffalo hump, hirsutism, and abdominal striae). 

A. Systemic intoxication associated with stonefish envenomation can include the rapid onset of hypotension, tachycardia, cardiac arrhythmias, myocardial ischemia, syncope, diaphoresis, nausea, vomiting, abdominal cramping, dyspnea, pulmonary edema, cyanosis, headache, muscular weakness, and spasticity. 

Easy fatigue, mild weakness, muscular twitching, fasciculations, cramps, generalized weakness, including muscles of respiration, with dyspnea and cyanosis. 

Pain, muscular weakness, cramps and ease of fatigue are the most usual symptoms of muscular disease. In most cases, it is diseases of the vascular or nervous system or problems with the processes providing energy within the muscle that are responsible for clinical problems with muscles. Other clinical problems include the muscular dystrophies, myotonic disorders, inflammatory myopathies and disorders of neuromuscular transmission (see Walton, 1996). The best known is Duchenne muscular dystrophy. 

Atropine is able to oppose these muscarinic effects. In addition, neostigmine, which has both a direct action as well as an indirect action that is mediated by acetylcholine on end-plate nicotinic receptors, may produce muscular fascicula-tion, muscular cramps, weakness, and even paralysis. These effects are not countered by atropine. Furthermore, neostigmine enhances gastric contraction and secretion. Neostigmine itself is metabolized by plasma acetylcholinesterase. 

Low magnesium levels can increase muscular cramp and musde weakness and cause changes in heart musde. Magnesium defidency can occur in alcoholism, in assodation with gastrointestinal disorders, after treatment with diuretics and as a result of severe renal disease. 

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