Diagnostic pitfalls of drug-induced immune hemolytic anemia

Immune hemolytic anemia (IHA) is a rare complication of drug administration. However, its true incidence remains obscure, as there are a number of factors that may lead to misdiagnosis. The clinical and serologic pictures are variable, and there is a great deal of unawareness that certain drugs can cause IHA. Furthermore, serologic results can be easily misinterpreted, resulting in a wrong diagnosis.

[Chlorthalidone better than hydrochlorothiazide in hypertension]

Thiazide diuretics have been the cornerstone in the pharmacological treatment of hypertension for more than 5 decades. Hydrochlorothiazide and chlorthalidone have been the 2 most commonly used diuretics in major clinical trials and are considered interchangeable. Nonetheless, hydrochlorothiazide has been much more widely prescribed than chlorthalidone, especially since nearly all available combinations with other antihypertensive drugs contain hydrochlorothiazide. However, whereas chlorthalidone at low doses has been shown repeatedly to reduce cardiovascular morbidity and mortality, such low doses of hydrochlorothiazide have never been shown to do this. Moreover, in direct comparison, chlorthalidone has a more sustained antihypertensive effect than hydrochlorothiazide, probably due to its very long half-life. These beneficial effects on blood pressure and cardiovascular events make chlorthalidone a tenable choice for the treatment of hypertension.

Successful control of intractable hypoglycemia using rapamycin in an 86-year-old man with a pancreatic insulin-secreting islet cell tumor and metastases

CONTEXT

Insulinomas are rare tumors of the pancreatic islet cells that produce insulin. Approximately 5 to 10% of these tumors are cancerous, and control of insulin secretion and hypoglycemia may be difficult in these patients. Malignant insulinomas generally respond poorly to traditional chemotherapeutic agent regimens. At present, streptozotocin is the only approved drug for the treatment of pancreatic islet cell tumors. SETTING AND PATIENT: This report describes a case of an elderly gentleman with a metastatic pancreatic insulinoma and severe hypoglycemia. A continuous infusion of octreotide lowered the blood glucose levels further. He required diazoxide, a thiazide diuretic, phenytoin, and a constant infusion of glucose to control the hypoglycemia and elevated insulin levels.

INTERVENTION

Rapamycin was administered at an oral dose of 2 mg/d.

RESULTS

On the mTOR (mammalian target of rapamycin) agent rapamycin, he was weaned off all drugs except for the thiazide diuretic and maintained euglycemia with a reduction of circulating insulin levels. He remained euglycemic for the past year with no evidence of tumor progression based on Octreoscan. His quality of life is excellent, and he remains active having recently completed a triathlon.

CONCLUSIONS

Rapamycin may provide a useful means of abrogating tumor growth and controlling hypoglycemia in malignant insulinomas by reducing the malignant beta-cell growth and proliferation as well as inhibiting insulin production.

A case of gain-of-function mutation in calcium-sensing receptor: supplemental hydration is required for renal protection

AIMS

The calcium-sensing receptor (CaSR) regulates the extracellular calcium level, mainly by controlling parathyroid hormon secretion and renal calcium reabsorption. In gain-of-function CaSR mutations, the genetic abnormalities increase CaSR activity leading to the development of such clinical manifestations as hypercalciuric hypocalcemia and hypoparathyroidism. We report a Japanese case of CaSR gain-of-function mutation and represent a therapeutic intervention based on the functional characteristics of CaSR in renal tubule.

METHODS AND RESULTS (CASE)

DNA sequence analysis revealed a heterozygous G to T mutation identified in a 12-year-old Japanese girl presenting with sporadic onset of hypercalciuric hypocalcemia and hypoparathyroidism. The mutation is located in the N-terminal extracellular domain of the CaSR gene, one of the most important parts for the three-dimensional construction of the receptor, resulting in the substitution of phenylalanine for cysteine at amino acid 131 (C131F) in exon 3. Based on the diagnosis of the gain-of-function mutation in the CaSR, oral hydrochlorothiazide administration and supplemental hydration were started in addition to calcium supplementation. The combination therapy of thiazide and supplemental hydration markedly reduced both renal calcium excretion and urinary calcium concentration from 0.4-0.7 to less than 0.1 mg/mg (urinary calcium/creatinine ratio) and from 10-15 to 3-5 mg/dl (urinary calcium concentration), respectively. This therapy stopped the progression of renal calcification during the follow-up period.

CONCLUSION

Supplemental hydration should be considered essential for the following reasons: (1) calcium supplementation activates the CaSR in the kidney and suppresses renal urinary concentrating ability, (2) the thiazide has a diuretic effect, (3) as calcium supplementation increases renal calcium excretion, the supplemental hydration decreases urinary calcium concentration by increasing urinary volume, thereby diminishing the risk of intratubular crystallization of calcium ion.

[Anxiodepressive and neuromediatory disorders in hypertensive patients. Effects of cypramil therapy]

AIM

To investigate psychic status and characteristics of neuromediatory metabolism in hypertensive patients, efficacy of antihypertensive therapy with lisinopril and hydrochlorthiaside with adjuvant citalopram (cipramil) which is a selective inhibitor of serotonin reuptake.

MATERIAL AND METHODS

Fifty patients with hypertension stage II (37 females, 13 males, mean age 48 years, mean duration of the disease 10.6 years) have undergone psychometric examination, estimation of evoked potentials P-300, 24-h monitoring of blood pressure. Plasma levels of epinephrine and norepinephrine, plasma and platelet levels of serotonin and 5-OIAA were measured at high-performance liquid chromatography.

RESULTS

Hypertensive patients were found to have high levels of depression, reactive and personality anxiety, subnormal quality of life. Blood pressure lowered more in patients given adjuvant cipramil.

CONCLUSION

Hypertensive patients have anxiodepressive disorders accompanied by monoamines disbolism. Cipramil effectively corrects these disorders.

Phototoxicity to sulphonamide-derived oral antidiabetics and diuretics: investigations in hairless mice

The oral antidiabetics glibenclamide, glipizide, glymidine, tolazamide and tolbutamide and the diuretics bemetizide, bendroflumethiazide, benzylhydrochlorothiazide, bumetanide, butizide, furosemide, hydrochlorothiazide, hydroflumethiazide and trichlormethiazide were investigated for phototoxic effects in hairless mice. The back of the animals (hr/hr-c3H/TifBom) was covered with Duoderm dressing, and at the site of two punched out holes 0.05 ml of the test substances at 0.25 mol/l concentration and the solvent alone as control were injected intradermally, respectively. Both test and control sites were irradiated with 6-12 J/cm2 of longwave UVA light from a "Bluelight 2000" apparatus (Hönle, Martinsried, Germany). Skin reactions were read at 24 and 48 h. Compared to the solvent alone, all of the test substances induced reactions (necrosis or oedema)--most frequently seen by macroscopic and histologic investigation and by measurements with a thickness gage. Injection of the test substance or solvent alone without or with subsequent UVA irradiation, as well as UVA alone, did not induce measurable skin changes in this model. Three oral antidiabetics and four diuretics, not yet described to induce photosensitivity in vitro nor in vivo, were detected as potential photosensitizers using our animal model.

Coadministration of thiazides increases the efficacy of loop diuretics even in patients with advanced renal failure

It is commonly assumed that thiazide diuretics are ineffective in patients with advanced renal failure (GFR < 30 ml/min/1.73 m2). Thiazides act on the nephron segment distal to the ascending thick loop of Henle, that is, the site of action of loop diuretics. Blockade of sodium reabsorption in the thiazide-sensitive segment should therefore obliterate the compensatory increase in sodium reabsorption seen after administration of loop diuretics and thus potentiate the natriuretic efficacy of loop diuretics even in advanced renal failure. In a single-blind, randomized, placebo controlled crossover study we compared the natriuretic and chloruretic effect of the loop diuretic, torasemide, given alone or in combination with the thiazide diuretic, butizid, in 10 patients with advanced renal failure (mean CIn 13.1 +/- 5.9 ml/min/1.73 m2). For two weeks patients adhered to a diet containing a standardized amount of Na+ and K+. On the 6th and 13th study days, two sham infusions were given to patients in order to assess basal 24-hour urinary electrolyte excretion. On the 7th and 14th days they were randomly allocated to receive either 50 mg i.v. torasemide in combination with a sham infusion or torasemide in combination with 20 mg i.v. butizid. Administration of torasemide alone significantly (P < 0.01) increased mean cumulative 24-hour excretion of sodium (from 154 +/- 30 to 232 +/- 59 mmol/24 hr) and chloride (from 128 +/- 21 to 233 +/- 84 mmol/24 hr) as compared with baseline.(ABSTRACT TRUNCATED AT 250 WORDS)

[Potassium canrenoate and the combination of potassium canrenoate-butizide in the therapy of light to moderate arterial hypertension]

The aim of the study was to evaluate the antihypertensive effect of K-canrenoate, alone or in combination with butizide, in mild to moderate essential hypertensives. Fifteen patients (supine diastolic blood pressure ranging from 95 to 114 mmHg) received K-canrenoate 50mg/die (step 1). In patients with supine diastolic blood pressure greater than 90 mmHg therapeutic regimen was modified at two-week intervals according to the following design: K-canrenoate 100 mg/die (step 2), K-canrenoate 50 mg + butizide 5 mg/die (step 3), K-canrenoate 100 mg + butizide 10 mg/die (step 4). Blood pressure control was achieved in 2 patients treated with K-canrenoate alone (step 2) and in 8 patients on a combined regimen (step 3), and it was maintained throughout the whole trial period (12 weeks); step 4 did not achieve the goal of therapy in the remaining 5 subjects. A statistically significant increase in triglyceridemia (123.2 +/- 42.1 vs 158.3 +/- 62 mg/dl) and uricemia (4.6 +/- 0.9 vs 5 +/- 0.9 mg/dl) was observed at the end of the follow-up period. Serum potassium levels remained stable in all patients. Therefore, K-canrenoate in combination with butizide is an effective and well tolerated drug in the treatment of mild to moderate essential hypertension.

In vitro aldose reductase inhibitory activity of N-aryl-glycine derivatives and their thioisosters

A series of N-arylglycine derivatives and their thioisosters (1-10) was synthesized and evaluated as in vitro aldose reductase inhibitors. Among these, (6-chloro-1,2,4-benzothiadiazine-1,1-dioxide-3-yl)-2-propanoic acid (5) shows an inhibitory activity (IC50:5.1 microM) comparable to Alrestatin.

[Effect of captopril therapy on sodium and water excretion in patients with liver cirrhosis and ascites]

Ascites in patients with cirrhosis of the liver frequently is refractory to diuretic treatment. It was postulated that vasoconstriction of the renal cortex, mediated by activation of the renin-angiotensin-aldosterone-system (RAAS), may be one course of the disturbed sodium- and water-excretion in these patients. We therefore investigated in 14 cirrhotic patients with ascites under constant diuretic treatment the effects of low-dose captopril therapy on urinary sodium- and potassium-excretion, body weight, abdominal girth, serum-sodium, -potassium, creatinine-clearance, plasma-renin-activity (PRA), plasma-aldosterone (PA) and mean arterial pressure (MAP). After a control period of 4 days the patients received 2 x 6.25 mg/d captopril for 5 days and 4 x 6.25 mg/d for further 5 days. Treatment was followed by a second control period without captopril. PRA increased significantly after 2 days of captopril treatment. 2 x 6.25 mg/d captopril induced a significant increase in sodium excretion and a significant decrease of body weight. MAP decreased slightly but significantly without clinical signs of hypotension. 4 x 6.25 mg/d captopril resulted in a further reduction of body weight and a further enhancement of sodium excretion. Three days after withdrawal of captopril sodium output was significantly reduced again.

CONCLUSION

In cirrhotic patients low-dose captopril seems to be efficient in the treatment of ascites resistant to diuretics without causing major side effects.

Simultaneous quantitative determination of butizide, potassium canrenoate and canrenone in tablets by high-performance liquid chromatography

A procedure for the simultaneous quantitative determination and selective identification of potassium canrenoate and butizide is proposed. The amount of canrenone, the degradation product of potassium canrenoate, is also determined. Elution of these compounds is investigated on LiChrosorb RP-18 and RP-8 columns. The analysis time was shorter on a RP-8 column while the specific identification was still possible. Therefore, the LiChrosorb RP-8 column was chosen. The eluent consisted of an acetonitrile--0.05 M phosphate buffer, pH 4 (45:55) mixture. Quantitative determination was performed at the absorption maximum of each compound: 286 nm for potassium canrenoate and for canrenone, 271 nm for butizide. This change in wavelength is performed automatically by the computer that controls the spectrophotometric diode array detector.

[Comparative study of 2 diuretic-containing combination preparations in patients with edematous heart failure]

The efficacy and tolerability of two combinations, namely 50 mg spironolactone + 20 mg furosemide (SF) or 50 mg spironolactone + 5 mg butizide (SB), were compared in a randomised intraindividual trial in 22 patients with congestive heart failure. The parameters used were: weight, ankle- and calf-circumference, blood pressure, resting pulse, resting ECG, spirometry and blood chemistry. The physicians' judgement of the success of treatment was also recorded. Clinical symptoms improved clearly in both groups and in most cases there was significant improvement of the various parameters. The trend towards improvement was more apparent with SF. The physicians considered SF to be more effective in 12 cases compared to one case with SB. In all other cases both treatments were considered equally effective. The blood chemistry data showed relevant differences: serum-potassium levels were less scattered with SF and showed a - desirable - shift into the upper normal range. The number of patients with elevated serum-creatinin-levels increased during SB-treatment whereas the opposite was noted with SF. This could be due to furosemide's positive effects on renal functions.

Enantiomers of benzothiadiazine diuretics by direct chromatographic resolution of the racemic drugs

A number of racemic benzothiadiazine diuretics and two carbonyl analogue drugs were resolved into their optical isomers by liquid chromatography on chiral polyacrylamides 1. Enantiomeric resolution, which was, in some cases, almost complete, depended considerably on the substitution of the heterocyclic moiety of the drug molecules. Synthesis of the new adsorbent lb is described. The enantiomers of the benzothiadiazines penflutizide (2a) and bendroflumethiazide (2b) in high optical purity, as well as enriched (+)-buthiazide (2j) were obtained by repeated chromatography on a semipreparative scale. Chiroptical data, optical purity employing the chromatographic method, and first-order racemization kinetics as a function of pH in aqueous solutions were determined.

Antihypertensive treatment using calcium antagonists in combination with captopril rather than diuretics

The antihypertensive efficacy of combination therapy with the angiotensin-converting enzyme inhibitor captopril and a diuretic or a calcium antagonist was compared in 16 patients with essential hypertension with a blood pressure of over 160/95 mm Hg having triple drug therapy. While monotherapy with a calcium antagonist--usually verapamil 500 mg/day or nitrendipine 70 mg/day--did not reduce diastolic blood pressure to greater than 95 mm Hg, this goal was achieved in 15 out of 16 patients with the combination of captopril (53 mg/day) and the calcium antagonists in the above dose (151 +/- 4/88 +/- 2 SEM mm Hg) and in 13 out of 16 patients with captopril (84 mg/day) and a diuretic (158 +/- 4/91 +/- 1 mm Hg). There was a direct relationship between intraindividual pressure responses to the two drug combinations (r = 0.88, p less than 0.001). Heart rate was similar and weight lower on the captopril-diuretic combination. Captopril's antihypertensive efficacy can be equally enhanced by calcium antagonists (without affecting renin long term) as by diuretics, which are thought to work by stimulating the renin-angiotensin system. The calcium antagonist-captopril combination may be of particular advantage in hypertensive patients who are otherwise difficult to treat.

Ex vivo antigen preparation for the serological detection of drug-dependent antibodies in immune haemolytic anaemias

Two patients with severe, intravascular haemolysis due to drug-dependent antibodies are described. The antibodies were directed against presumptive metabolites of buthiazide (International Non-proprietary Name, butizide) and nomifensine. Their detection was possible only in the presence of ex vivo antigens (i.e. fresh serum of volunteers after ingestion of the drugs) while in vitro antigen preparations yielded inconclusive results. Both antibodies lysed normal red cells in the presence of ex vivo antigens and complement. The buthiazide-related antibody was IgG (subclass IgG1), the nomifensine-related antibody was IgM. We conclude that the use of ex vivo antigens is of great importance in the serological evaluation of cases with suspected drug-dependent immune haemolysis.

Porokeratosis of Mibelli: benzylhydrochlorothiazide-induced new lesions accompanied by eosinophilic spongiosis

We observed the course of development of porokeratosis stimulated by benzylhydrochlorothiazide (BHCTh) in normal-appearing skin of a patient with long-standing stable porokeratosis of Mibelli. A 72-year-old Japanese man had had porokeratosis of Mibelli for more than 50 years. During administration of BHCTh for 1 year because of his hypertension, a lichenoid drug eruption developed over the lesions of porokeratosis on the flexor aspects of his legs. Readministration of BHCTh by another physician for 6 months resulted in the occurrence of a similar drug eruption that converted into typical skin lesions of porokeratosis 8 weeks later. Serial microscopic examination suggested that BHCTh administration resulted in eosinophilic spongiosis and cornoid lamella formation, which developed into epidermal changes characteristic of porokeratosis.

[Electrolyte excretion following administration of various diuretics in healthy females]

The fractional water and electrolyte excretion was measured in healthy women after an intake of different thiazides in combination with spironolactone. The combination of 100 mg spironolactone either with 5 mg bendrofluazide or with 10 mg butizide increased significantly the diuresis over the whole day. The greatest effect was between the fourth and the eighth hour. The combination of 100 mg spironolactone with 20 mg furosemide augmented diuresis only in the first two hours. All tested drugs induced a significantly increased excretion of sodium, whereas potassium excretion did not change. Magnesium excretion correlated with sodium excretion.

[Metabolic effects of a fixed combination (betablocker plus saluretic) in long-term treatment of arterial hypertension (author's transl)]

In 23 patients with essential hypertension of stage I and II according to the WHO, the effects of a fixed combination of a beta-receptor-blocker plus saluretic composed of 20 mg of metipranolol (Disorat 20) and 2.5 mg of butizid (Saltucin) = Torrat on blood pressure and important metabolic parameters (glucose, glucose tolerance, cholesterol, triglyceride, uric acid, plasma potassium and whole body potassium) were tested over a 6-month treatment period.

RESULTS

blood pressure and pulse rate were significantly reduced; bradycardia (pulse rate less than 60/min) was not observed. The metabolic parameters showed no significant changes during the 6-month treatment period. In no case did the therapy have to be discontinued because of undesirable effects. The investigations show that the combination has a good antihypertensive effect with few side-effects and that it has no influence on important metabolic parameters during long-term therapy.

[Treatment of essential hypertension with a combination of propranolol, spironolactone-thiabutazide and dihydralazine (author's transl)]

In 61 out-patients with essential hypertension, grade I or II, propranolol was administered alone in increasing doses (3 x 40 mg/d or 3 x 80 mg/d) or, if there was insufficient response, with a double or triple combination consisting additionally of spironolactone (50 mg/d)-thiabutazide (5 mg/d) and dihydralazine (3 x 25 mg/d). This treatment schedule achieved normal pressures in 51 patients, in 22 on 40 mg, in 7 on 80 mg propranolol, in 16 after the addition of the diuretic, and in 6 with the triple combination. Four patients had to be excluded from the study because they developed either marked bradycardia or anxiety states or paraesthesias after propranolol (3 x 40 mg/d). On chronic beta-adrenergic blockade the serum potassium level increased slightly, but remained within normal limits. The initial value of plasma-renin activity was highest in the group of those who responded to the propranolol treatment.

GLC analysis of hydrochlorothiazide in blood and plasma

GLC with electron-capture detection was successfully applied to the analysis of hydrochlorothiazide in human blood and plasma with a sensitivity (0.05 mug/ml) suitable for use with persons on therapeutic dosage levels. On-column methylation with trimethylanilinium hydroxide in methanol was employed to convert hydrochlorothiazide and its bromo analog, which served as the internal standard, to their tetramethyl derivatives.

[Use of aldactone-saltucine for patients with chronic circulatory insufficiency]

In 50 patients with congestive heart failure a compound diuretic drug aldactone--saltucine was used. Diuresis, urine excretion of sodium and potassium, rate of glomerular filtration and tubular reabsorption of water, as shown by endogenous creatinin, were measured in all patients. In 13 patients the study was conducted dynamically in 8 three-hour portions of urine during 24 hours. In 6 patients the drug was administred in combination with furosemid. In 11 patients the effect of several days of therapy with aldactone-saltucine upon the urine excretion of electrolytes and their plasma level was studied. The effect of the compound drug was evaluated separately in patients with IIA, IIB and III stage of circulatory insufficiency. Aldactone-saltucine was shown to execute a distinct diuretic and natriuretic effect that lasts for 24 hours after a single dose. The drug has also a clear potassium-preserving action that manifests itself in a low level of potassium excretion with urine and an elevation of a potassium plasma level. A combination of aldactone-saltucine with furosemid considerably increases diuresis and natriuresis, without any signifcant increase in potassiuresis, which permits to use these drugs in the severest cases of congestive heart failure.

[Use of aldactone-saltucine in patients with heart failure]

Aldactone-saltucine was used in 52 patients with Stage IIB-III cardiac failure. The efficiency of the drug was evaluated by the dynamics of the clinical course, diuresis, body weight, blood and urine levels of electrolytes, and in some patients by the urine excretion of aldosterone. Aldactone-saltucine is a sufficiently effective diuretic agent that, without producing excessively fast diuresis, exerts after a course of therapy a beneficial effect, increasing mainly natriuresis, without concomitant hypokalemia. The diuretic effect of the drug ensued irrespectful of the initial level of urine aldosterone excretion. After a course of treatment urine aldosterone excretion tended to increase. Hyperaldosteronuria was noted in only 1/3 of the patients.

[Spironolactone and thiabutazide in the treatment of essential hypertension (author's transl)]

The anti-hypertensive effect of spironolactone and thiabutazide was tested on 47 unselected patients with primary hypertension. They were divided into two groups according to the change in plasma-renin activity in response to furosemide administration: those with and those without response to stimulation, and sub-groups with low, normal or high plasma-renin activity (low renin hypertension; normal renin hypertension; high renin hypertension). During both 4-week treatment periods there was a distinct fall in systolic blood pressure, most marked in the patients without plasma renin stimulation (after spironolactone of about 26.2 mm Hg, after thiabutazide 29 mm Hg), the diastolic pressure fall being only slight in all groups (about 5-10 mm Hg). The plasma-renin activity and plasma-aldosterone concentration increased in all groups, after both spironolactone and thiabutazide three-to fourfold compared with the basal value, even in patients without change in plasma-renin activity after furosemide injections. Serum sodium content decreased after administration of spironolactone, increasing again after subsequent thiabutazide administration. Serum potassium content increased after spironolactone, decreasing after thiabutazide. There was no significant difference between either individual groups or different treatment periods with spironolactone or thiabutazide as far as weight, urine volume or electrolyte excretion in 24-hour urine was concerned.