Adverse reactions to frusemide in hospital inpatients

Efficacy of comprehensive group-based education in lowering body weight, uric acid levels, and diuretic use in patients with chronic kidney disease: a retrospective study

BACKGROUND

Patient education for the management of chronic kidney disease (CKD) is attracting attention. Therefore, this study aimed to analyze changes in body weight, uric acid, and estimated-glomerular filtration rate (eGFR) in patients with CKD after a group-based education during admission.

METHODS

Overall, 157 patients with CKD, who were discharged from the nephrology department of our hospital between January 2015 and October 2019, received group-based education or individual-based education by nurses at admission. Deltas of body weight, uric acid, and eGFR, 6 months from baseline, were compared between group- and individual-based education using the Wilcoxon rank sum test.

RESULTS

In total, 60 patients receiving group-based education (G group, n =35) or individual-based education (I group, n =25) during admission were included in this retrospective study. The patient characteristics at baseline were as follows: age mean, 72 ± SD 9; 16 females and 44 males; body weight, 62 ± 17 kg; eGFR median, 21 (IQR: 14, 29) mL/min/1.73 m2; UA, 7 (6.1, 7.5) mg/dL; and estimated intake of salt 6.9 (6.2, 8.4) g/day. Delta eGFR (mL/min/1.73 m2) was -1 (-3, 3) for G group and -1 (-2.5, 2) for I group (p = 0.8039). Delta body weight (kg) was -0.4 (-1.6, 0) for G group and 0 (-0.45, 0.95) for I group (p = 0.0597). Delta uric acid (mg/dL) was -1.1 (-1.6, 0.1) for G group and -0.2 (-1.1, 0.5) for I group (p = 0.0567). In patients with higher sodium intake (≥ 117.4 mEq/day), delta body weight was significantly lower in the group-based education group than in the individual-based education group (p = 0.0398).

CONCLUSIONS

A comprehensive group-based education in patients with CKD may effectively suppress body weight and uric acid in 6 months along with less frequent diuretic use.

Modulation of Urate Transport by Drugs

BACKGROUND

Serum urate (SU) levels in primates are extraordinarily high among mammals. Urate is a Janus-faced molecule that acts physiologically as a protective antioxidant but provokes inflammation and gout when it precipitates at high concentrations. Transporters play crucial roles in urate disposition, and drugs that interact with urate transporters either by intention or by accident may modulate SU levels. We examined whether in vitro transporter interaction studies may clarify and predict such effects.

METHODS

Transporter interaction profiles of clinically proven urate-lowering (uricosuric) and hyperuricemic drugs were compiled from the literature, and the predictive value of in vitro-derived cut-offs like C_max/IC₅₀ on the in vivo outcome (clinically relevant decrease or increase of SU) was assessed.

RESULTS

Interaction with the major reabsorptive urate transporter URAT1 appears to be dominant over interactions with secretory transporters in determining the net effect of a drug on SU levels. In vitro inhibition interpreted using the recommended cut-offs is useful at predicting the clinical outcome.

CONCLUSIONS

In vitro safety assessments regarding urate transport should be done early in drug development to identify candidates at risk of causing major imbalances. Attention should be paid both to the inhibition of secretory transporters and inhibition or trans-stimulation of reabsorptive transporters, especially URAT1.

Real-world evidence for the safety of ipragliflozin in elderly Japanese patients with type 2 diabetes mellitus (STELLA-ELDER): final results of a post-marketing surveillance study

OBJECTIVE

To investigate the real-world safety of ipragliflozin in elderly Japanese patients with type 2 diabetes mellitus (T2DM).

RESEARCH DESIGN AND METHODS

Japanese patients (≥65 years old) who were first prescribed ipragliflozin within 3 months after its launch in April 2014 were registered in this post-marketing surveillance (PMS). Final data collection was in July 2015. Survey items included demographics, treatments, adverse drug reactions (ADRs), vital signs, and laboratory variables.

RESULTS

The PMS included 8505 patients (4181 males/4324 females). The mean age and diabetes duration were 72.3 years and 10.6 years, respectively. In 84.3% of patients, ipragliflozin was prescribed at 50 mg/day, which was continued unchanged. Overall, 16.91% of patients experienced 1880 ADRs, and 165 ADRs were classified as serious in 127 patients (1.49%). ADRs of special interest included skin complications, volume depletion, polyuria/pollakiuria, genital infection, urinary tract infection, renal disorders, hypoglycemia, cerebrovascular disease, cardiovascular disease, malignant tumor, fracture, and ketone body-related events.

CONCLUSIONS

This 1-year PMS revealed probable ADRs in elderly Japanese patients with T2DM prescribed ipragliflozin in real-world settings, with no new safety concerns. The risk factors for ADRs varied but could be rationalized. The results should help physicians to identify possible treatment-emergent ADRs in ipragliflozin-treated patients.

Magnetic resonance and computed tomography in pediatric urology: an imaging overview for current and future daily practice

The main imaging modality of the urinary tract in children is ultrasound. When further cross-sectional morphologic examination and/or functional evaluation is required, magnetic resonance (MR) imaging is the logical and optimal second step, particularly in pediatric patients. There are two main exceptions to this. The first one is when after an ultrasound, additional diagnostic imaging for urolithiasis is needed. The second one involves severe polytrauma, including blunt abdominal trauma. In this review, an overview of the MR imaging and computed tomography examinations important for current and future daily pediatric uroradiologic practice is presented.

Sodium and Potassium Disturbances in the Elderly

OBJECTIVE

To study the incidence of sodium and potassium disturbances in a population of the very old elderly, with respect to medication with potential effects on electrolyte levels.

DESIGN AND SETTING

Cross-sectional study of subjects aged >/=75 years, based on data from the Kungsholmen project, a population-based study of elderly in an urban area of Stockholm, Sweden.

STUDY PARTICIPANTS

1558 elderly individuals (1178 women and 380 men), mean age 81.4 years, providing information about drug use and serum electrolyte data.

MAIN OUTCOME MEASURES

Data on drug use was based on personal interviews. Hyponatraemia was defined as a serum sodium concentration <136 mmol/L, hypernatraemia as a serum sodium concentration >146 mmol/L, hypokalaemia as a serum potassium concentration <3.5 mmol/L and hyperkalaemia as a serum potassium concentration >5.0 mmol/L.

RESULTS

Hyponatraemia was found in 147 subjects (9.4% of the study population) and hypernatraemia in five individuals (0.3%). Hypokalaemia was found in 39 (2.5%) and hyperkalaemia in 43 (2.8%) of the subjects. The prevalence of hyponatraemia (p < 0.001), hypokalaemia (p < 0.05) and hyperkalaemia (p < 0.05) increased with age. Hyponatraemia was found more often in women than in men (p < 0.05). Hypernatraemia was more frequent in subjects who lived in institutions (p < 0.001). The occurrence of hyponatraemia was associated with the use of carbamazepine, laxatives (enema), diuretics and ACE-inhibitors; hypernatraemia was associated with osmotically active laxatives. Hypokalaemia was associated with thiazide-related and combination diuretics; and hyperkalaemia was associated with potassium-sparing diuretics, beta-blockers, cytostatic drugs and tricyclic antidepressants.

CONCLUSIONS

The present study demonstrated the association between electrolyte level disturbances and several types of drugs in a population of the very old elderly. Our results underline the importance of monitoring serum electrolyte levels in the elderly, not only in relation to the use of diuretics, but also several other drugs.

Effect of bolus injection versus continuous infusion of furosemide on diuresis and neurohormonal activation in patients with severe congestive heart failure

Previous studies have demonstrated that continuous infusion of furosemide results in increased diuresis and natriuresis compared with bolus administration of the drug in patients with severe heart failure. We reasoned that continuous infusion of furosemide caused less activation of neurohumoral mechanisms, since other studies have shown that bolus administration of furosemide may activate this system. We therefore tested the hypothesis that continuous administration of furosemide would increase water and sodium excretion due to less activation of neurohormones. Eight patients with severe heart failure were studied during continuous infusion over 24 h and bolus injections of furosemide twice daily in a randomized cross-over study. Bolus administration of furosemide increased diuresis and natriuresis significantly in the first 4 h after administration compared with continuous administration, but this was later reversed, resulting in similar 24 h total output. The neurohormones measured at baseline were all markedly elevated. Neither regimens of furosemide caused any further significant changes in neurohumoral response except that pro-ANF decreased more during the first 8 h after bolus administration compared to continuous infusion. This study has demonstrated that bolus administration of furosemide in conventional doses is equally effective as continuous intravenous infusion in patients with severe heart failure. This may be due to maximal neurohormonal activation in severe heart failure (NYHA III-IV) which could not be further activated by bolus administration.

Diuretic-related hypokalaemia: the role of diuretics, potassium supplements, glucocorticoids and beta 2-adrenoceptor agonists. Results from the comprehensive hospital drug monitoring programme, berne (CHDM)

All 5,047 consecutive inpatients admitted to the Internal Medicine Division of a teaching hospital (Zieglerspital, Berne) between 1982 and 1985 were registered in accordance with the CHDM (Comprehensive Hospital Drug Monitoring) questionnaire of adverse drug reactions (ADRs). Of them, 2,439 were treated with at least one potassium losing diuretic. The hospital records of the patients were reviewed with particular regard to serum potassium levels, and on the basis of this evaluation, the patients were assigned to four different diuretic treatment groups, and the incidence of hypokalaemia related to diuretic treatment was estimated. The overall rate of occurrence of hypokalaemia was 21.1% at a serum potassium level < 3.5 mmol.l-1, and 3.8% < 3.0 mmol.l-1. Hypokalaemia of less than 3.5 mml.l-1 developed 24.9% (217/870) of patients treated with potassium losing diuretics alone; in 19.7% (101/513) treated with potassium losing diuretics in conjunction with potassium substitution, in 15.1% (66/438) treated with a combination of diuretics (potassium losing with potassium sparing), and in 20.0% (12/60) treated with combined diuretics and potassium substitution. Only the differences between the first and the two subsequent groups were statistically significant. The overall incidence of hypokalaemia below 3.0 + mmol.l-1 was significantly lower in the patients on combined diuretics without potassium substitution than in the patients on potassium losing diuretics with potassium substitution. Oral or parenteral administration of glucocorticoids (prednisone 5 to 2,000 mg/d) was a significant risk factor for hypokalaemic events. beta 2-Adrenoceptor agonists had not effect. The patient's age, sex, renal function and numbers of drugs received were evaluated in a multivariate analysis, in order to take into account their influence on the risk of developing hypokalaemia. The number of drugs above 12 (and, less importantly, female sex) was the main risk factor for this ADR. The comparison between hypokalaemia and hyperkalaemia in this group of inpatients showed the significance of reduced renal function in the occurrence of hyperkalaemia.

Furosemide-associated fever

We describe a 5-month-old infant who had fever of unknown origin leading to an exhaustive evaluation during a 7-week period. Fever caused by the use of furosemide was proved; the fever resolved after discontinuation of this medication and recurred after its reintroduction.

Extra-natriuretic effects of atrial peptide in humans

To evaluate extra-natriuretic effects of atrial natriuretic peptide (ANP), plasma ANP (pANP) levels were assessed in seven healthy men on low-sodium diet (80 mEq NaCl/day), in basal conditions and during stepwise infusion of human ANP (2, 4, 8 and 16 ng/min/kg). To determine the individual physiological (PHY) pANP level, we measured pANP in the same subjects after a high-salt diet (400 mEq NaCl/day), that is, in a physiological stimulation of ANP. We then compared the effects of the PHY levels of ANP to the effects of pharmacological (PHA) pANP levels. Neither PHY nor PHA pANP levels modified creatinine clearance or blood pressure. The progressive rise in pANP levels was associated with increases in urinary excretion of Na+, K+ and urea. ANP alone respectively accounted for 41%, 30% and 92% of the increase in natriuresis, kaliuresis and urea excretion that occurred after changing salt intake from 80 to 400 mEq/day. Pharmacological ANP levels raised CH2O and reduced UOsm. Interestingly, PHA levels were associated with significant decrease in serum K+ (from 4.5 +/- .1 to 4.0 +/- .1 mEq/liter) and plasma urea (from 31.9 +/- 5 to 24.2 +/- 4 mg/dl). The mean cumulative urinary potassium and urea losses corresponded to the theoretical body losses of potassium and urea; moreover, the individual cumulative urinary losses of potassium and urea significantly correlated with the corresponding decrement in their plasma levels. In conclusion, ANP has both physiological and pharmacological significance in the control of potassium and urea metabolism by decreasing plasma levels of K+ and urea through effects on the renal excretory function.

Possible severe thrombocytopenia associated with a single dose of plicamycin

OBJECTIVE

To report a case of possible severe thrombocytopenia associated with administration of a single dose of plicamycin.

CASE SUMMARY

A 73-year-old man with prostate cancer was admitted to the hospital with hypercalcemia (total serum calcium concentration 4.02 mmol/L) and a low baseline platelet count (152 x 10(9)/L). Because of his symptomatic hypercalcemia, he was treated with NaCl 0.9%, furosemide, oral inorganic phosphate, and a single dose of plicamycin (15 micrograms/kg). Five days after plicamycin administration his platelet count decreased to 52 x 10(9)/L, and continued to decrease further even after the transfusion of four units of platelets to a nadir of 7 x 10(9)/L (hospital day 20). A second transfusion produced a small increase in his platelet count. The patient's clinical status continued to deteriorate, however, and he subsequently died.

DISCUSSION

Plicamycin and other drugs that may induce thrombocytopenia are reviewed. The time course between plicamycin administration and the development of thrombocytopenia in our patient is assessed. Other contributing factors such as a low baseline platelet count and advanced age are also addressed.

CONCLUSIONS

It is likely that the severe thrombocytopenia experienced by our patient was caused by a single dose of plicamycin. Adjusting the dosage for a patient's renal function as well as close monitoring of the platelet count are necessary when administering this drug. We report this case to remind clinicians of the potential for the development of severe thrombocytopenia following administration of a single dose of plicamycin.

Intermittent administration of furosemide vs continuous infusion preceded by a loading dose for congestive heart failure

Several reports have suggested that continuous intravenous administration of loop diuretics may be superior to intermittent administration. We performed a prospective randomized crossover study comparing intermittent intravenous administration (IA) of furosemide with continuous infusion following a single loading dose (LDCI) in nine patients with severe congestive heart failure. At the time of hospital admission, patients were randomly assigned to one of two treatment groups. One group (four patients) received an IV bolus injection of furosemide followed immediately by a continuous infusion for 48 h. The second group (five patients) was treated with three IV bolus injections a day for 48 h. Total doses of furosemide were equivalent in the two groups. After 48 h, each patient was crossed over to the other method and treated for an additional 48 h. LDCI produced significantly greater diuresis and natriuresis than IA (total urine output increased by 12 to 26 percent, total sodium excretion increased by 11 to 33 percent) (p less than 0.01). There were no significant differences in side effects between the two methods. These results indicate that LDCI may be a preferred method for administration of furosemide in patients with congestive heart failure.

Electrolyte disorders in the elderly

Electrolyte abnormalities in the elderly are common and it is most important to establish if drug treatment is the cause, as this is so easily remediable. The vast majority of electrolyte disturbances will settle with treatment of the underlying condition. Great attention must be paid to fluid balance to establish if the patient is receiving too little, which could induce hypernatraemia, or too much, particularly after surgery, which may induce hyponatraemia. Electrolyte levels should be checked ideally before and certainly after the prescription of diuretics. In the elderly it is important that the electrolyte levels be checked if the patient exhibits any vague symptoms, particularly if they are taking a diuretic. Care must be taken in replacing potassium as in most cases this is unnecessary and may have a significant morbidity.

The incidence of gout in renal transplant recipients

To determine the frequency of gout in our renal transplant population and to identify any predisposing factors, we retrospectively examined the outpatient records of all patients transplanted between January 1980 and July 1984 in whom the allograft functioned for at least 1 year. Two hundred forty-three charts were sufficiently complete to be evaluated. Of the 211 patients receiving corticosteroids and cyclosporine (CyA) as immunosuppression, 25 had at least one documented episode of gout (9.7% of total, 11.8% of CyA patients); no episodes occurred in the 32 patients receiving azathioprine and corticosteroid therapy (P = .05). The time from transplantation to the first episode of gout ranged from 4 months to 4 years. Of the patients without gout, 103 of the 186 receiving CyA (55.5%) and eight of 32 receiving azathioprine (25%) had asymptomatic hyperuricemia (serum uric acid greater than 8.5 mg/dL for men, greater than 7.0 mg/dL for women, P less than .01). The number of patients receiving diuretics in the CyA treated group was 142 of 211 (67%) v 12 of 32 (37.5%) in the azathioprine group. However, the increased incidence of gout or hyperuricemia in patients receiving CyA was not due to the effect of the diuretic alone. There was no correlation between the serum creatinine and uric acid in either the CyA or azathioprine group (r value for CyA group = -.06 and for the azathioprine group = -.26). Compared with patients receiving azathioprine, we conclude that there is an increased incidence of gout and/or hyperuricemia in renal transplant patients treated with CyA.(ABSTRACT TRUNCATED AT 250 WORDS)

Contribution of the urea appearance rate to diuretic-induced azotemia in the rat

Studies were performed to evaluate the contribution of the urea appearance rate to the elevated plasma urea concentration found during diuretic-induced sodium depletion. Negative sodium balance of -1162 + 29 microEq/100 g body wt was induced over a four day period by the administration of furosemide, 20 to 30 mg/kg/d i.p., to rats ingesting a sodium free diet. When compared with sodium replete controls, sodium depletion significantly increased the plasma urea concentration (65.0 +/- 3.1 vs. 26.4 +/- 1.1 mg/dl) through both an increase in the urea appearance rate (160 +/- 5.2 vs. 125 +/- 3.5 mg/day/100 g body wt), and a decrease in the urea clearance rate (1.99 +/- 0.14 vs. 3.16 +/- 0.12 ml/min/kg). The urea appearance rate increased on the first day of diuretic administration, remained elevated three days after stopping diuretics, rapidly returned to control levels after sodium repletion, and was significantly correlated with the magnitude of sodium deficit. Similar results were obtained when diuretic-induced sodium depletion was produced in adrenalectomized animals. After four days of sodium depletion the plasma concentration was increased for some amino acids but not for the plasma total amino acid, nitrogen concentration. The results indicate that sodium depletion increases the urea appearance rate through a mechanism that is independent of adrenal function. Thirty to sixty percent of the elevation in plasma urea concentration that occurs in the rat during diuretic-induced sodium depletion can be accounted for by an enhanced urea appearance rate.

Differences between acute and long-term metabolic and endocrine effects of oral beta-adrenoceptor agonist therapy with pirbuterol for cardiac failure

The metabolic, hormonal and haemodynamic effects of oral pirbuterol, a new beta 2-adrenoceptor agonist, were studied acutely (n = 19) and after 3 months treatment (n = 11) in patients with severe heart failure receiving chronic frusemide therapy. In the acute study fasted patients (n = 10) showed reductions in plasma K+ (P less than 0.005) and cortisol (P less than 0.01) and increases in plasma glucose (P less than 0.005), insulin (P less than 0.01), lactate (P less than 0.005) and pyruvate (P less than 0.0025). These acute changes were less in unfasted subjects (n = 9). Maximal increase in stroke volume occurred at approximately half the plasma pirbuterol concentration required for maximal effect on plasma insulin. Treatment with pirbuterol for 3 months was associated with sustained increases in stroke volume and fasting plasma glucose and insulin, but there was loss of all other acute metabolic effects. Despite concurrent frusemide and digoxin therapy acute hypokalaemia caused no adverse effects. Hypokalaemia did not occur with chronic pirbuterol administration.

Diuretics. Clinical pharmacology and therapeutic use (Part II)

25 years have elapsed since the introduction of the first effective oral diuretic, chlorothiazide. Diuretics are now amongst the most widely prescribed drugs in clinical practice worldwide. Availability of these drugs has not only brought therapeutic benefit to countless numbers of patients but it has at the same time provided valuable research tools with which to investigate the functional behaviour of the kidney and other electrolyte-transporting tissues. Despite many remaining gaps in our knowledge of the biochemical processes involved in diuretic drug action, available compounds can be divided into 5 groups on the basis of their preferential effects on different segments of the nephron involved in tubular reabsorption of sodium chloride and water. Firstly, there is a heterogeneous group of chemicals that share the common property of powerful, short-lived diuretic effects that are complete within 4 to 6 hours. These agents act on the thick ascending limb of Henle's loop and are known as 'high ceiling' or 'loop' diuretics. The second group are the benzothiadiazines and their many related heterocyclic variants, all of which localise their effects to the early portion of the distal tubule. The third group comprises the potassium-sparing diuretics which act exclusively on the Na+-K+/H+ exchange mechanisms in the late distal tubule and cortical collecting duct. The action of drugs in groups 2 and 3 is prolonged to between 12 and 24 hours. The fourth group consists of diuretics that are chemically related to ethacrynic acid but have the unusual property of combining within the same molecule the property of saluresis and uricosuria. These compounds have actions, to different individual extents, in the proximal tubule, thick ascending limb, and early distal tubule and are known as 'polyvalent' diuretics. Finally, there is a mixed group of weak or adjunctive diuretics which includes the vasodilator xanthines such as aminophylline, and the osmotically active compounds such as mannitol. The metabolic consequences of continued diuretic usage are considered along with non-metabolic sequelae such as ototoxicity or interactions with other concurrent treatments. The relationships between the clinical benefits conferred and the potential harms generated by long term diuretic therapy are also discussed.

Potassium and the heart

The electrical stability of the heart is more sensitive to the extracellular than to the intracellular potassium concentration. During exercise, extracellular potassium varies rapidly. Catecholamines also modulate the plasma potassium concentration. Hypokalaemia of any cause can precipitate arrhythmias. Ischaemic myocardium loses potassium into the extracellular space within seconds and the cell becomes depolarized. The rise of the extracellular potassium ion concentration accounts for many of the early electrophysiological changes. Abrupt changes of plasma potassium concentration in normal myocardium and a high potassium concentration in ischaemic myocardium can set up electrical forces which initiate arrhythmias. The same phenomenon can account for changes on the electrocardiogram early after the cessation of an exercise test in a patient with ischaemic heart disease. Accumulation of potassium between cells in response to an increase of heart rate is a possible mechanism for false positive exercise tests and Syndrome X.

Frusemide/amiloride combination ('Frumil') in heart failure: an open, multi-centre study in general practice

A total of 95 patients seen in general practice with oedema associated with heart failure took part in an open study of the efficacy and tolerability of a combination tablet containing 40 mg frusemide and 5 mg amiloride. The study was of 3-months' duration and patients received a dosage of 1 to 2 tablets once daily. Efficacy was assessed by physicians' scores for ankle, leg and lumbosacral oedema and pulmonary crepitations, body weight and physicians' global clinical impression. In addition, patients recorded their symptom severity in study diaries during the first 7 days of therapy, and the day before each trial visit. On the basis of the physicians' overall impression of response to therapy, 89 (93.7%) of the patients were graded as 'excellent', 'good' or 'adequate' responders. Improvement in severity scores for oedema, crepitations and body weight also followed this pattern, although certain symptoms were mild or absent in some patients at recruitment. Nine patients were withdrawn from the study, 4 due to drug-related adverse effects. There was no evidence of any consistent change in serum potassium levels or other clinical chemistry, liver function tests or haematology during the study.

Total body potassium in patients receiving chlorthalidone and metoprolol for hypertension

Measurements of potassium status were reviewed in 23 hypertensive patients receiving metoprolol either alone or in combination with chlorthalidone or chlorthalidone plus potassium over an average period of nine months. There was no statistically significant change in plasma potassium, total blood cell or total body potassium in patients on long-term metoprolol. Four subjects (17%) in the diuretic groups developed hypokalaemia (serum potassium less than 3.0 mmol/l) in the absence of significant falls in total blood cell or total body potassium. Thus the use of chlorthalidone plus potassium did not provide adequate prophylaxis against hypokalaemia even in metoprolol recipients. The study confirms that monitoring parameters of potassium handling is still necessary in beta-blocker recipients who also receive diuretics alone or in a fixed-dose combination with potassium.

Diuretic withdrawal--a need for caution

Diuretic therapy was withdrawn from 42 patients receiving modest drug doses for reasons other than hypertension, active heart failure and renal or hepatic oedema, with frequent assessment by clinical, biochemical and radiological methods for 12 weeks. Of 38 patients who could have completed the study, 27 (71%) did so without ill-effect. Eleven (29%) patients deteriorated clinically or radiologically, 7 within 2 weeks of discontinuing diuretics, and 1 of them died after acute pulmonary oedema and a haematemesis, despite intensive resuscitation. The outcome of drug withdrawal could be predicted in 35 of the patients using a multifactorial discriminant analysis but individual parameters had poor predictive value. The lack of demonstrable benefit in many patients and the incidence of adverse effects associated with long-term diuretic therapy suggest that withdrawal should be considered more often in this type of patient. However, there is a need for caution in this situation and withdrawal should only be attempted if close medical supervision and radiological examination of the chest are possible.

Drug attributed alterations in potassium handling in congestive cardiac failure

Information from a comprehensive drug surveillance programme has been reviewed to give details of the frequency of drug-related hypo- and hyperkalaemia in a group of 3879 patients admitted to hospital with cardiac failure. Hypokalaemia was commoner in females, was unrelated to blood area concentration on admission and was twice as common amongst recipients of potassium-losing diuretics who did not take potassium supplements than amongst those who received potassium retaining diuretics. By contrast hyperkalaemia was strongly related to blood urea concentration on admission. It was also related to in-hospital diuretic therapy; being thrice as frequent amongst recipients of aldosterone antagonists than amongst those receiving potassium-losing diuretics without additional supplements. Life-threatening hypo- and hyper-kalaemia were rare in this group of patients with heart failure, occurring with approximately equal frequencies of about 2 per 1000 patients treated.

Diuretics and the institutional elderly: a case against routine potassium prescribing

In 14 elderly male residents of a veterans' care complex who were receiving diuretic therapy for cardiac failure, oral potassium (K) supplements were withdrawn. Plasma and erythrocyte K levels were measured immediately before and six weeks after withdrawal of the supplements (38 mEq K daily). The controls comprised 19 elderly residents without disease and not taking drugs likely to influence K status. Study subjects and controls were receiving the same diet (average daily K content 100 mEq). After withdrawal of K supplements, the mean plasma K level fell significantly but the mean erythrocyte K level remained unchanged and did not differ from the control values. For a further six weeks after the withdrawal period, 7 subjects were treated with Aldactazide (diuretic hydrochlorothiazide plus K-sparing spironolactone). The plasma K level increased significantly but the erythrocyte K level remained unchanged. It was concluded that, in this setting, diuretic-induced hypokalemia is not necessarily accompanied by intracellular K depletion and that routine prophylaxis with K supplements or K-sparing agents is unnecessary and not without risk. Such therapy should be reserved for patients considered at special risk of K depletion because of known poor dietary intake, advanced liver disease, secondary hyperaldosteronism with renovascular hypertension, gastrointestinal losses, or nondiuretic medication known to affect K status adversely.