Nonfatal methazolamide-induced aplastic anemia

An 83-year-old man developed nonfatal aplastic anemia after taking methazolamide for three months. We made a diagnosis of methazolamide-induced aplastic anemia, discontinued all medication, gave the patient platelet and red blood cell transfusions, and treated him with oxymetholone. Approximately four months after initiation of treatment, the patient felt well, and he is currently receiving packed red blood cell transfusions every three weeks.

Effects of acetazolamide on myotonia

Myotonia can occur in the periodic paralyses, particularly the hyperkalemic form. The beneficial response to acetazolamide in hypokalemic and hyperkalemic periodic paralysis has led us to study the effect of acetazolamide in 9 patients with disorders having myotonia as the major problem, 7 with myotonia congenita and 2 with paramyotonia congenita. Patients were studied before acetazolamide administration with glucose and potassium loading tests. All patients had an increase in myotonia with potassium, but no weakness occurred with either test. Acetazolamide treatment decreased myotonia in all patients and in 3 proved the most satisfactory therapy. Side-effects during acetazolamide therapy included paresthesias in 5 patients and renal calculus in 1. Flaccid weakness occurred in a patient with paramyotonia congenita. Acetazolamide treatment was associated in all patients with partially compensated metabolic acidosis and lowering of serum potassium within the normal range. Kaliuresis was also noted during introduction of therapy. Acetazolamide appears to be an acceptable treatment for occasional patients with myotonia who are unresponsive to or intolerant of other therapies.

Abnormal cisternogram associated with Diamox therapy

A cisternogram characteristic of normal-pressure hydrocephalus was obtained from a patient on Diamox who was being evaluated for rapid mental deterioration. A repeat cisternogram after Diamox was discontinued was nearly normal. We hypothesize that the initial abnormality resulted from reduced cerebrospinal fluid production caused by carbonic anhydrase inhibition; this defect (reduced flow) led to a net reflux of tracer into the ventricles. The reflux is believed to be due to the reduction of bulk cerebrospinal fluid from the ventricles.

Acute renal failure from the use of acetazolamide (Diamox)

The clinical histories of two patients are presented, who both developed haemorrhagic anuria after a short course of therapy with the carbonic anhydrase inhibitor, acetazolamide (Diamox). The clinical findings, in particular the radiological changes, are illustrated in this potentially fatal condition. The therapeutic success of immediate relief of the ureteric obstruction is emphasized and it is hoped that this report will act as a reminder of the importance of this agent as a cause of anuria.

A model for ulnar dysmelia

The treatment of pregnant rats with the carbonic anhydrase inhibitor, acetazolamide, produced gross limb malformations primarily affecting the forepaw, but also producing variable ulnar dysmelia. Analysis of the cytoarchitecture of the ulnar dysmelic limbs showed the presence of cartilaginous and fibrocartilaginous connections between the ulnar and radial chondroepiphyses, with variable deformation of the radial chondroepiphysis by the tethering effect (although the growth plate, per se, did not appear affected at the stage of development studied). The extremely variable experimental appearances duplicated most of the variations seen in the human disease analogue, and suggest this drug-induced embryopathy may be useful as a model for the study of postaxial forelimb deformities in the postnatal phase in order to adequately assess the structural changes of disparate growth between radius and ulna due to the presence of the cellular continuity between the two distal chondroepiphyses.

Carbonic anhydrase inhibitor side effects. Serum chemical analysis

Multiple serum chemical values were examined in 92 patients with chronic glaucoma who were treated with the carbonic anhydrase inhibitors (CAIs) acetazolamide or methazolamide, seeking relationships between serum composition and symptomatic side effects. Of the 92 patients, 44 complained of a symptom-complex of malaise, fatigue, weight loss, depression, anorexia, and loss of libido, which we have found most commonly to threaten continuation of therapy. Patients who had this symptom complex were significantly more acidotic than those without it. Ten of 24 patients who had chemical evidence of excessive acidosis reported a dramatic alleviation of symptoms when sodium bicarbonate was administered, although their serum CO2-combining power changed little. There was no correlation of the symptom complex with serum potassium concentration, except in a few patients who were simultaneously receiving chlorothiazide diuretics for systemic hypertension and who became frankly hypokalemic.

Acetazolamide-accelerated anticonvulsant osteomalacia

Severe osteomalacia was present in two epileptic patients who were under long-term treatment with congeners of phenytoin, phenobarbital, and acetazolamide. These patients showed slightly low serum calcium, normal or low serum phosphate, and normal parathyroid hormone concentrations. Discontinuation of acetazolamide produced an immediate threefold drop in the level of urinary calcium excretion and a slight rise in tubular reabsorption of phosphate, with no dectectable change in serum calcium or phosphate concentrations. Acetazolamide may have accelerated the development of osteomalacia by several mechanisms, including increased renal calcium excretion.

Low-dose methazolamide and intraocular pressure

Sixteen patients with increased intraocular pressure (over 20 mm Hg) received 25 and 50 mg of oral methazolamide, twice daily, during consecutive weeks and then 500 mg (Sequels) of acetazolamide. The two methazolamide regimens produced significant decreases in intraocular pressure. Acetazolamide treatment resulted in a greater decrease in intraocular pressure but more systemic acidosis and side effects.

[Palatine clefts following puncture of the amniotic sac in the rat]

1) Amniotic sac puncture is a reliable procedure for induction of a cleft palate in rat foetuses 15 days old. 2) This possibility persists during the first hours of day 16. 3) When applied to rats after 16 days 12 hours of pregnancy, amniocentesis does't induce a cleft palate. 4) Treatment during this critical stage of pregnancy with substances able to reduce the amniotic fluid volume, such as acetazolamide and hydrocortisone, doesn't produce cleft palate.

Acetazolamide-induced weakness in paramyotonia congenita

Acetazolamide has been shown to be effective prophylaxis for both hypokalemic and hyperkalemic paralysis. A patient with paramyotonia congenita, a related disorder with myotonia and episodic weakness, was studied during treatment with acetazolamide. Athough the patient's myotonia was virtually abolished, severe quadriparesis was produced during each trial of acetazolamide. This response distinguished this patient's condition from other forms of familial periodic paralysis and suggests that acetazolamide may be deleterious to some patients with periodic paralysis.

Teratogenic effect of anticonvulsant drugs

Multiple malformations in all four children of a mother taking anticonvulsant drugs are reported, along with the extended family pedigree.

Urinary calculus during methazolamide therapy

A 68-year-old white man with Paget's disease and open-angle glaucoma was treated with methazolamide, 50 to 100 mg three times daily. Ten months after the medication was initiated he developed ureteral colic and a calcium oxalate stone was surgically removed. Three months after the drug was reinstituted the patient passed three calcium phosphate stones. This suggested a casual relationship between methazolamide and stone formation, although renal calculi also complicate Paget's disease and acetazolamide had been administered briefly.

[Prevention of altitude sickness]

In experimental and clinical studies the effect of Acetazolamide (Diamox) on acute mountain sickness was investigated. It could be established that Acetazolamide does influence the symptoms, the man effect seems to be a reduction of the respiratory alkalosis, which is found in control persons in high altitudes. Observations made with a group of 25 tourists mountaineering in the Cordilleras (South America) over 24 days in altitudes between 3200 and 6000 m are described. In accordance with other published data the favorable influence of Acetazolamide on acute mountain sickness could be confirmed. Persons taking Acetazolamide were more efficient and better prepared to cope with the extreme situations in high altitude. They also showed to be more resistent to other diseases, which are following the stress in high altitude and are caused by the different climate and food.

Effect of acute and chronic metabolic acidosis on serum immunoreactive parathyroid hormone in man

The effects of acute and chronic metabolic acidosis on serum immunoreactive parathyroid hormone (iPTH) were studied. Acute metabolic acidosis induced by administration of ammonium chloride (NH4Cl) produced a barely detectable increase in serum iPTH. Chronic NH4Cl administration produced a marked elevation of serum iPTH that was well correlated with the magnitude of acid-induced hypercalciuria but not with the degree of acidosis. Acetazolamide administration produced an equivalent degree of acidosis, but hypercalciuria was minimal and iPTH increased only marginally. Methionine administration caused moderate hypercalciuria and a significant but moderate increase in iPTH. Chronic NH4Cl-induced acidosis produced no hypercalciuria when dietary sodium intake was rigidly restricted, and under these conditions serum iPTH remained normal. When sodium intake was suddenly increased while maintaining the acid load, hypercalciuria appeared and was followed by progressive rise in serum iPTH equivalent to that observed during chronic NH4Cl-induced acidosis in subjects consuming salt ad lib. These results indicate that chronic acidosis elevates iPTH mainly by producing hypercalciuria and that acidosis itself is not a primary stimulus to PTH secretion.

Acetazolamide-induced renal calculi

The occurrence of urinary calculi associated with acetazolamide therapy is described. Patients with a history of urinary stones or surgery are a significant risk for further calculus formation when treated with acetazolamide. The concurrent use of sodium bicarbonate further potentiates this risk.

Renal tubular acidosis and skeletal demineralization in patients on long-term anticonvulsant therapy

Three children ranging from seven to 12 years of age from unrelated families were given long-term anticonvulsant therapy including acetazolamide (Diamox). These children had rickets and renal tubular acidosis. Investigations have suggested (1) secondary hyperparathyroidism due to hypocalcemia of rickets and (2) prolonged acetazolamide therapy were responsible for acidosis as a result of reduction of bicarbonate reabsorption in the kidney. A clear-cut recovery from acidosis and rickets was seen in two patients following medication with high doses of vitamin D, an oral supplement of phosphorus, and discontinuance of acetazolamide therapy.

Renal failure associated with acetazolamide therapy for glaucoma

Presented is a case of acute renal failure induced by acetazolamide therapy for glaucoma. The 69-year-old patients recovered rapidly after oral administration of fluids and sodium bicarbonate. This sulfonamide like nephropathy should be differentiated from acetazolamide-related calcium phosphate nephrolithiasis.

Teratogenesis of acetazolamide in the CBA/J and SWV strains of mice. I. Teratology

SWV mice were totally resistant to the teratogenic and embryolethal actions of acetazolamide. The time of maximal sensitivity to acetazolamide-induced ectrodactyly in the CBA/J strain was the middle of day 10; the dose response at this time was studied. Comparison of the responses of the two strains and reciprocal hybrids indicated that sensitivity is a property of the embryo and is not maternally mediated. SWV mice were also resistant to dichlorphenamide which suggests they may be resistant to many or even all teratogenic carbonic anhydrase inhibitors.

Effects of acetazolamide on cerebral ischemia and infarction after experimental occlusion of middle cerebral artery

Acetazolamide was given to five of ten cats for 48 to 54 hours after extradural occlusion of a middle cerebral artery (MCA). At seven to eight days later, measurements of regional cerebral blood flow (CBF) and estimates of the sizes of the ischemic and infarcted areas of the brains were made. Neurological deficits were more severe and the ischemic and infarcted regions were larger in the cats given acetazolamide. Cerebral edema (brain swelling) was present and reactive hyperemia was common in the treated cats, even one week after MCA occlusion. The hypercapnia and decreases of pH of nonischemic brain tissue that are caused by acetazolamide are harmful for ischemic brain tissue, presumably because of vasodilatation in nonischemic brain tissue with resultant increases of intracranial pressure and decreases of CBF of ischemic regions.