Cumulative Incidence of Thiazide-Induced Hyponatremia : A Population-Based Cohort Study

BACKGROUND

According to drug labels, the frequency of thiazide-induced hyponatremia is unknown or uncommon to very rare (that is, <1 in 10 000 to <1 in 100), but the exact burden remains unclear.

OBJECTIVE

To estimate the increase in the cumulative incidence of hyponatremia using thiazide diuretics compared with nonthiazide antihypertensive drugs in routine clinical practice.

DESIGN

Population and register-based cohort study using target trial emulation.

SETTING

Denmark, 1 January 2014 to 31 October 2018.

PARTICIPANTS

Two target trials were emulated among persons aged 40 years or older who had no recent prescription for any antihypertensive drug, had no previous hyponatremia, and were eligible for the studied antihypertensive treatments. The first target trial emulation compared new use of bendroflumethiazide (BFZ) versus a calcium-channel blocker (CCB). The second target trial emulation compared new use of hydrochlorothiazide plus a renin-angiotensin system inhibitor (HCTZ-RASi; that is, combination pill) versus a RASi alone.

MEASUREMENTS

Two-year cumulative incidences of sodium levels less than 130 mmol/L using stabilized inverse probability of treatment-weighted survival curves.

RESULTS

The study compared 37 786 new users of BFZ with 44 963 of a CCB and 11 943 new users of HCTZ-RASi with 85 784 of a RASi. The 2-year cumulative incidences of hyponatremia were 3.83% for BFZ and 3.51% for HCTZ-RASi. The risk differences were 1.35% (95% CI, 1.04% to 1.66%) between BFZ and CCB and 1.38% (CI, 1.01% to 1.75%) between HCTZ-RASi and RASi; risk differences were higher with older age and higher comorbidity burden. The respective hazard ratios were 3.56 (CI, 2.76 to 4.60) and 4.25 (CI, 3.23 to 5.59) during the first 30 days since treatment initiation and 1.26 (CI, 1.09 to 1.46) and 1.29 (CI, 1.05 to 1.58) after 1 year.

LIMITATION

The study assumed that filled prescriptions equaled drug use, and residual confounding is likely.

CONCLUSION

Treatment initiation with thiazide diuretics suggests a more substantial excess risk for hyponatremia, particularly during the first months of treatment, than indicated by drug labeling.

PRIMARY FUNDING SOURCE

Independent Research Fund Denmark.

A review of the prescribing trend of thiazide-type and thiazide-like diuretics in hypertension: A UK perspective

Thiazide diuretics have been the cornerstone of hypertension treatment for >5 decades. Most recent European and American guidelines recommend both thiazide-type and thiazide-like diuretics as first-line drugs for all patients with hypertension. In contrast, diuretics are not regarded as first-line treatment in the UK and in patients who are to be initiated on a diuretic treatment, thiazide-like molecules, such as chlortalidone and indapamide are the preferred option. This review examines the prescribing trend of the 4 most commonly prescribed thiazide diuretics for the treatment of hypertension in the UK. Prescription cost analysis data were obtained for both 2010 and 2016/2017 for each region of the UK to analyse the impact of the 2011 National Institute for Health and Care Excellence hypertension guidelines on the trend in thiazide diuretic prescribing. Overall, the prescriptions of thiazide diuretics declined over the years. Bendroflumethiazide is the most commonly prescribed diuretic in the UK and despite some geographical differences, thiazide-type diuretics are more widely used than thiazide-like. The use of indapamide increased significantly between 2010 and 2016/2017 while chlortalidone was rarely employed. Of the many factors affecting trends in prescriptions, clinical inertia, treatment adherence, availability of the products and the lack of fixed dose combinations may play a role.

The effect of indapamide vs. bendroflumethiazide for primary hypertension: a systematic review

The aims of the current review were to compare the efficacy of monotherapy with bendroflumethiazide vs. indapamide on mortality, cardiovascular outcomes, blood pressure, need for intensification of treatment and treatment withdrawal. Two authors independently screened the results of a literature search, assessed the risk of bias and extracted relevant data. Randomized clinical trials of hypertensive patients of at least a 1-year duration were included. When there was disagreement, a third reviewer was consulted. Risk ratio (RR) and mean differences were used as measures of effect. Two trials comparing bendroflumethiazide against placebo, one comparing indapamide with placebo and three of short duration directly comparing indapamide and Bendroflumethiazide, were included. No statistically significant difference was found between indapamide and bendroflumethiazide for all deaths [RR 0.82; 95% confidence interval (CI) 0.57, 1.18], cardiovascular deaths (RR 0.82; 95% CI 0.55, 1.20), noncardiovascular deaths (0.81; 95% CI 0.54, 1.22), coronary events (RR 0.73; 95% CI 0.30, 1.79) or all cardiovascular events (RR 0.89; 95% CI 0.67, 1.18). Indapamide performed worse for stroke (RR 2.21; 95% CI 1.19, 4.11), even though a reduction in RR compared with placebo was observed in both groups. There was no statistically or clinically significant difference between indapamide and bendroflumethiazide in blood pressure reduction (mean absolute difference <1 mmHg). The present review highlights a lack of studies to answer the review question but also a lack of evidence of superiority of one drug over the other. Therefore, there is a clear need for new studies directly comparing the effect of these drugs on the outcomes of interest.

A combined connectivity mapping and pharmacoepidemiology approach to identify existing medications with breast cancer causing or preventing properties

PURPOSE

We applied a novel combined connectivity mapping and pharmacoepidemiological approach to identify medications that alter breast cancer risk.

METHODS

The connectivity mapping process identified 6 potentially cancer-causing (meloxicam, azithromycin, rizatriptan, citalopram, rosiglitazone, and verapamil) and 4 potentially cancer-preventing (bendroflumethiazide, sertraline, fluvastatin, and budesonide) medications that were suitable for pharmacoepidemiological investigation. Within the UK Clinical Practice Research Datalink, we matched 45,147 breast cancer cases to 45,147 controls based on age, year, and general practice. Medication use was determined from electronic prescribing records. We used conditional logistic regression to calculate odds ratios (ORs) for the association between medication use and cancer risk after adjustment for comorbidities, lifestyle factors, deprivation, and other medication use.

RESULTS

Bendroflumethiazide was associated with increased breast cancer risk (OR: 1.11; 95% CI: 1.06, 1.15); however the connectivity mapping exercise predicted that this medication would reduce risk. There were no statistically significant associations for any of the other candidate medications, with ever use ORs ranging from 0.93 (95% CI: 0.78, 1.11) for azithromycin to 1.16 (95% CI: 0.99, 1.37) for verapamil.

CONCLUSIONS

In this instance, our combined connectivity mapping and pharmacoepidemiological approach did not identify any additional medications that were substantially associated with breast cancer risk. This could be due to limitations in the connectivity mapping, such as implausible dosage requirements, or the pharmacoepidemiology, such as residual confounding.

[Rhabdomyolysis caused by thiazid-induced hypokalaemia]

This case report presents a 38-year-old woman who developed rhabdomyolysis following severe hypokalaemia due to a thiazid diuretic. Rhabdomyolysis is a severe condition with an incidence of 28% in hypokalaemic patients. It should be considered to measure concentrations of S-myoglobin and S-creatine kinase in severe cases of hypokalaemia. Thiazid diuretics can cause severe hypokalaemia with life-threatening complications and monitoring of S-potassium is advised during therapy.

Hyponatraemia due to a thiazide diuretic. A case report

The time course of profound hyponatraemia has been followed in a patient who developed this condition after 6 week's treatment with a thiazide diuretic, bendroflumethiazide. The case is related to the syndrome of inappropriate secretion of antidiuretic hormone.

Low-dose antihypertensive treatment with a thiazide diuretic is not diabetogenic. A 10-year controlled trial with bendroflumethiazide

Blood pressure (BP) and metabolic variables were determined initially and after 1, 2, 4, 6 and 10 years' treatment in two groups of hypertensive men (n = 53 each) randomized to bendroflumethiazide 2.5-5 mg/day or propranolol 160-320 mg daily. There was no significant differences in BP or metabolic variables between the two groups at entry. BP was reduced to the same degree by both treatments. Five men in the propranolol group and one man in the thiazide group developed clinically overt diabetes during follow-up. Fasting blood sugar increased slightly but significantly though equally in both groups. Oral glucose tolerance was initially impaired to the same degree in both groups but improved significantly during treatment with both drugs. Fasting insulin increased slightly but to the same degree. While serum potassium decreased significantly in the thiazide group, the total body potassium was unchanged in this group. In the propranolol group, serum potassium rose, while total body potassium decreased significantly. Serum urate increased in both groups, though slightly more during thiazide treatment. One case of gout was found in each group. There was no difference in serum lipids between the two groups. The finding in this long-term trial indicate that in middle-aged men with mild to moderate hypertension a low-dose thiazide diuretic like bendroflumethiazide is as effective and safe an antihypertensive agent as the beta-blocker propranolol is and that it does not induce diabetes. The total clinical picture favors the retention of thiazide diuretics as a first choice drug in hypertension.

Incidence and importance of metabolic side-effects during antihypertensive therapy

Three long-term, randomised trials examining antihypertensive treatment with either diuretics or beta-blockers are in progress. On the basis of these, the following conclusions may be drawn regarding metabolic side-effects. Diuretics decrease whereas beta-blockers increase serum potassium. Neither drug has any obvious influence on total body potassium. Serum urate increases on both drugs but more so in those taking diuretics. Serum triglycerides increase while total serum cholesterol is unchanged in both treatments. It is still a matter of controversy whether there is a decrease in glucose tolerance and an increase in the incidence of diabetes in patients on diuretics. The possible negative influence of metabolic side-effects on morbidity and mortality may limit the beneficial effects of blood pressure reduction, especially in patients with low pressures before treatment. Thus, it seems crucial to minimise theses side-effects. Since they are dose-related for both diuretics and beta-blockers, the use of low doses and, if needed, combination treatment is preferable.

Ventricular dysrhythmias in middle-aged hypertensive men treated either with a diuretic agent or a beta-blocker

The purpose of this study was to identify the frequency of cardiac dysrhythmias in two similar groups of hypertensive middle-aged males (age 45-66). They had previously been randomized either to a diuretic treatment (n = 42), or a beta-blocking agent (n = 41). A 24-hour ambulatory Holter monitoring, and serum potassium, was obtained in all patients, serum magnesium was measured in 35 patients. The mean number of ventricular premature beats (VPBs) and the frequency of complex arrhythmias (19 vs. 5) was significantly higher in the diuretic group (p less than 0.01). The serum potassium was significantly lower (p less than 0.001) in the diuretic group, and there was a significant (p less than 0.005) inverse correlation between the number of VPBs and the serum potassium in all treated patients. The patients with complex arrhythmias were older (p less than 0.01) than the remainder of the patients. No correlation between serum magnesium and VPBs or complex arrhythmias was found. This study demonstrates increased frequency of VPBs in older hypertensive males, treated with diuretics, and that hypokalaemia predisposes to increased cardiac arrhythmias. We conclude that in older mildly hypertensive men hypokalaemia should be avoided.

Antihypertensive effect and side-effects of bendroflumethiazide and propranolol

The antihypertensive effect and side-effects during 12 months' treatment with bendroflumethiazide and propranolol have been compared in two randomly selected, equally large groups (n= 53) of previously untreated male hypertensives. Systolic BP above 170 or diastolic BP above 105 mmHg on two occasions were defined as hypertension. The same BP reduction was achieved in both groups. During the 12 months' treatment one subject on bendroflumethiazide developed diabetes mellitus and one on propranolol developed cardiac decompensation. None developed gout. Contrary to what had been presumed, glucose tolerance improved during 12 months' treatment with both agents, while there were no changes in fasting blood sugar, insulin or triglyceride concentrations. No changes were found in serum potassium or total body potassium during 12 months' bendroflumethiazide treatment, while serum potassium increased during treatment with propranolol. Uric acid increased slightly during treatment with both agents. Prolongation of the follow-up to 24 months did not change any of the findings regarding metabolic changes during treatment. The frequency of subjective side-effects decreased to the same extent during treatment with both drugs. It is concluded that bendroflumethiazide and propranolol are equally useful as antihypertensive agents and that the risk of impariment of glucose metabolism and potassium balance seems to be very slight during treatment with bendroflumethiazide in mild hypertension.

Comparison of effects of combined ACE inhibitor and low-dose thiazide diuretic with ACE inhibitor alone on insulin action in patients with hypertension and Type 2 diabetes: a double-blind crossover study

AIMS

To establish the safety in terms of insulin sensitivity of a low dose thiazide/ACE inhibitor combination.

METHODS

We examined the effects on insulin sensitivity of captopril either alone or in combination with low-dose bendroflumethiazide (1.25 mg) in 15 hypertensive Type 2 diabetic patients. Insulin action was assessed using an isoglycaemic hyperinsulinaemic clamp in a double-blind, randomised, crossover study after a 6-week placebo run-in and following two 12-week treatment periods with captopril (C) (100 mg) alone or in combination with bendroflumethiazide (CB) (1.25 mg).

RESULTS

Blood pressure was lower following CB compare to C (138/83 vs. 144/85 mmHg; P < 0.05) and both were lower than baseline (153/92 mmHg; P < 0.01). CB resulted in a significant increase in fasting plasma glucose compared to C (9.6 +/- 2.6 vs. 8.5 +/- 1.6 mmol/l; P < 0.05). Exogenous glucose infusion rates required to maintain isoglycaemia during hyperinsulinaemia were lower after CB compared to C (25.1 +/- 13.3 vs. 34.2 +/- 16.8 micromol/kg/min; P < 0.01) as were isotopically determined glucose utilisation rates (29.0 +/- 12.4 vs. 36.6 +/- 17.3 micromol/kg/min; P < 0.05). There was no significant difference in fasting endogenous glucose production between treatments (CB 9.3 +/- 3.3 vs. C 8.6 +/- 1.6 micromol/kg/min), nor between suppression following insulin (CB 4.0 +/- 2.1 vs. C 4.3 +/- 3.1 micromol/kg/min).

CONCLUSIONS

Combination of low-dose bendroflumethiazide with captopril lowered blood pressure but resulted in deleterious effects on insulin action compared to captopril alone.

Flecainide cardiotoxicity precipitated by electrolyte imbalance. Caution with thiazide diuretics

A man presented with recurrent syncope, weakness and fatigue. His ECG showed marked QRS widening and he had gross hyponatraemia and hypokalaemia. His medications included bendroflumethiazide (long term) and flecainide (started 2 months previously). This presentation was consistent with flacainide cardiotoxicity exacerbated by electrolyte disturbance. The syncopal episodes probably represented life-threatening arrhythmias. The ECG and symptoms resolved completely once the electrolytes were corrected. Increased cardiotoxicity with hypokalaemia is documented, but not widely recognised. Hyponatraemia-induced flecainide cardiotoxicity has not been documented. The clinical effects of flecainide are due to use-dependent block of sodium channels. There are reports that support the use of hypertonic sodium salts to reverse flecainide toxicity via antagonism at the receptor. By this rationale, hyponatraemia would lead to Flecainide toxicity. Flecainide has been shown to reduce salt absorption in animal bowel. It is possible that in combination with bendroflumethiazide it acted synergistically to produce profound electrolyte disturbance. Flecainide cardiotoxicity has a significant mortality and can present non-specifically. Thus, early recognition is essential. This case demonstrates the importance of strict electrolyte control in patients who are on flecainide. We would discourage concomitant use of flecainide and bendroflumethiazide.

Thiazide diuretic prescription and electrolyte abnormalities in primary care

AIMS

Thiazide diuretics have a number of well-documented metabolic adverse effects. The aim of this study was to estimate the frequency of hyponatraemia and hypokalaemia amongst patients taking a thiazide diuretic in primary care.

METHODS

A computerized search of the electronic prescribing and laboratory records of six UK general practices was performed. Of the 32 218 adult patients identified, 3773 had received at least one prescription for a thiazide between the years 1990 and 2002.

RESULTS

Detailed prescribing data were available for 2942 patients of whom 951 (32.3%) had a recorded check of their electrolytes. One hundred and ninety-six (20.6%) had a sodium and/or potassium concentration below the normal range. The sodium distribution had a negative skew (-1.8) and in 130 (13.7%) patients was within the hyponatraemic range. Hypokalaemia was less common, occurring in 79 (8.5%) patients. Hyponatraemia was significantly associated with increased age; the odds ratio for developing hyponatraemia in patients over 70 years was 3.87 compared with those of < or = 70 years. Hypokalaemia was significantly associated with increased thiazide dose.

CONCLUSIONS

Prescription of a thiazide diuretic in primary care is associated with a high frequency of hyponatraemia and hypokalaemia. Thiazides should be prescribed at low dose and the risk of hyponatraemia, especially in the elderly, should be considered and monitored for when prescribing these agents.

Cyclooxygenase inhibition causes marked impairment of renal function in elderly subjects treated with diuretics and ACE-inhibitors

BACKGROUND

Treatment with angiotensin-converting enzyme (ACE)-inhibitors is known to cause an initial reduction in glomerular filtration rate (GFR) in patients with congestive heart failure. The long-term beneficial effects of ACE-inhibitors in these patients can be counteracted by cyclooxygenase-inhibitors.

AIMS

To quantify the negative renal effects of the cyclooxygenase-inhibitor diclofenac in elderly healthy subjects and to assess how treatment with an ACE-inhibitor, after activation of the renin-angiotensin system, influences these renal effects.

METHODS

Fourteen elderly, healthy subjects received oral diclofenac and placebo in a double-blind cross-over fashion. The study was divided in two parts; in part one, subjects received no pre-treatment and in part two, the subjects were given pre-treatment with bendroflumethiazide and enalapril in order to activate the renin-angiotensin system.

RESULTS

Diclofenac induced significant (p<0.05) decreases in GFR, urine flow, excretion rates of sodium and potassium, electrolyte clearance, osmolality clearance and free water clearance both with and without renin-angiotensin system activation. Least square means (95% CI) of all observations during the first 6 h after dosing showed that diclofenac caused a reduction in GFR from 71 (64-78) to 59 (52-66) ml/min. After pre-treatment, diclofenac further reduced GFR from 60 (52-67) to 48 (40-55) ml/min. After diclofenac administration, urine flow fell from 7.4 (6.4-8.3) to 5.1 (4.2-6.1) ml/min, after pre-treatment, diclofenac gave a further reduction from 4.1 (3.1-5.1) to 2.2 (1.3-3.2) ml/min. More than half of the reductions were caused by the pre-treatment.

CONCLUSION

Renal function in elderly, healthy subjects is impaired after acute intake of diclofenac. This impairment is observed both with and without activation of the renin-angiotensin system and ACE-inhibitor treatment but is more pronounced after pre-treatment.

Efficacy and Safety of 24 Weeks of Therapy with Bendroflumethiazide 1.25???mg/day or 2.5???mg/day and Potassium Chloride Compared with Enalapril 10???mg/day and Amlodipine 5???mg/day in Patients with Mild to Moderate Primary Hypertension

BACKGROUND

The efficacy and safety of therapy with low-dose bendroflumethiazide 1.25 mg/day or 2.5 mg/day and potassium chloride was compared with that of enalapril 10 mg/day and amlodipine 5 mg/day in patients with mild to moderate primary hypertension.

STUDY DESIGN

This was a multicentre study in general practice with patients randomised in a double-blind fashion and on open-label treatment. After a washout phase that lasted 4-6 weeks, 312 patients with a diastolic blood pressure of between 100 and 115 mm Hg were randomised in a double-blind fashion to treatment with either bendroflumethiazide 1.25 mg/day and potassium chloride (n = 117), bendroflumethiazide 2.5 mg/day and potassium chloride (n = 60), amlodipine 5 mg/day (n = 61) or enalapril 10 mg/day (n = 60), all given once daily (numbers in parentheses indicate the intention-to-treat population, with a total of 298 patients). The primary efficacy parameter was the reduction in diastolic blood pressure. Effects on systolic blood pressure, heart rate, biochemical variables, adverse events and quality of life were studied as secondary efficacy parameters.

RESULTS

All treatments reduced diastolic blood pressure significantly; reductions were as follows: 6.8 mm Hg with bendroflumethiazide 1.25 mg/day, 9.1 mm Hg with bendroflumethiazide 2.5 mg/day, 10.8 mm Hg with amlodipine 5 mg/day and 6.8 mm Hg with enalapril 10 mg/day. The reduction in diastolic blood pressure on amlodipine was significantly greater than on bendroflumethiazide 1.25 mg/day and enalapril 10 mg/day (p = 0.013). The percentage of patients achieving a diastolic blood pressure of < 95 mm Hg was 34% (SD 4.4) with bendroflumethiazide 1.25 mg/day, 48% (SD 6.5) with bendroflumethiazide 2.5 mg/day (p = 0.075 vs bendroflumethiazide 1.25 mg/day), 57% (SD 6.3) with amlodipine 5 mg/day (p = 0.004 vs bendroflumethiazide 1.25 mg/day) and 41% (SD 6.4) with enalapril 10 mg/day (p = 0.41 vs bendroflumethiazide 1.25 mg/day) [mean reductions]. The effect on systolic blood pressure was similar with all treatments. No clinically significant changes occurred in heart rate, serum potassium, blood glucose, serum urate or serum cholesterol levels. The incidences of adverse events were similar in the low-dose bendroflumethiazide groups, with significantly higher incidences in the enalapril and amlodipine groups. Quality of life was similar in the different treatment groups, but the study had limited power to detect any difference in this parameter.

CONCLUSION

The present study has confirmed, in a general practice population, that low-dose bendroflumethiazide (bendroflumethiazide 1.25-2.5 mg/day) in combination with potassium chloride is a well tolerated and efficacious first-line treatment for patients with mild to moderate essential hypertension.

Effects of furosemide and bendroflumethiazide on saliva flow rate and composition

Aim of this study was to evaluate the effect on saliva flow rate and composition and on perceived xerostomia. The study used a Latin square design, all subjects being once daily (at 7.00 a.m.) taking the bendroflumethiazide (2.5 mg), furosemide (40 mg), or placebo, in a randomised order. Each treatment period of 7 days was separated by wash-out periods of 14 days. Unstimulated and paraffin chewing stimulated whole saliva, and 3% citric acid stimulated parotid and submandibular-sublingual secretion were collected twice daily, at 7.30 a.m., with the patients in a fasting condition (morning values), and at 10.30 a.m., about 2 h after intake of a standard breakfast (lunchtime values), on day 0 (baseline), day 1 (acute treatment), and day 7 (chronic treatment). Saliva flow rates were measured and all four secretions were analysed for the concentration of sodium, potassium, chloride, and total protein. Xerostomia was assessed by means of a Visual Analogue Scale. Statistical analysis used the Wilcoxon signed rank test. For flow rate, only that of submandibular-sublingual secretion was affected, significantly so in the morning during chronic treatment with both drugs. In resting whole saliva the output of both sodium and chloride tended to decrease especially during treatment with bendroflumethiazide, while in submandibular-sublingual secretion the output of all the electrolytes was decreased, especially for potassium and chloride and during treatment with furosemide. Further, xerostomia tended to increase during treatment with furosemide, statistically significant at lunchtime during chronic treatment. In conclusion, this study has demonstrated a modest effect on salivary flow rate and a more pronounced effect on saliva composition, especially in submandibular-sublingual secretion during treatment of healthy volunteers with therapeutic doses of two different diuretics, encouraging clinical studies in hypertensive patients and basic research as to the presence of a thiazide sensitive Na-Cl cotransporter in human salivary glands.

A case of hypertension and hyperkalaemia

A52-year-old man was referred urgently to hospital by his GP because he had hyperkalaemia (7.3 mmol/litre; normal range 3.5–5.0 mmol/litre). Two months previously he was diagnosed as having diabetes mellitus when he was admitted to hospital with diabetic ketoacidosis. At that time his plasma sodium was 126 mmol/litre (normal range 133–147 mmol/litre), potassium 2.7 mmol/litre, urea 18 mmol/litre (normal range 2.5–7.5 mmol/litre) and creatinine 159 μmmol/litre (normal range 60–120 μmol/litre). Bendrofluazide, nifedipine and atenolol were stopped. Six weeks later he felt unwell, visited his doctor, and was found to be hypertensive. He was started on lisinopril 5 mg once daily. Ten days later he was still hypertensive, and lisinopril was increased to 10 mg once daily and routine plasma urea and electrolytes were measured.

His past medical history includes a Colles' fracture in 1992. At this time, hypertension and hyperkalaemia were noted and investigated. He was diagnosed as having Gordon's syndrome. Three of his daughters and two of his granddaughters were also found to have the syndrome. His father had been hypertensive and died suddenly at the age of 40 years. His uncle had also died suddenly at the age of 33 years.

On examination his height was 1.60 m, body mass index (BMI) was 30 kg/m2 and blood pressure was 168/75 mmHg. Heart, chest, abdominal, and neurological examination were normal. The electrocardiogram did not show manifestations of hyperkalaemia.

The hyperkalaemia was treated with insulin/glucose infusion. Lisinopril was stopped and bendrofluazide was started with normalization of plasma potassium level and blood pressure.

Effects of thiazide- and loop-diuretics, alone or in combination, on calcitropic hormones and biochemical bone markers: a randomized controlled study

OBJECTIVE

Diuretics are commonly used drugs that in addition to their effect on the cardiovascular system also affect calcium homeostasis and bone metabolism. We evaluated the effects of loop diuretics (LD) and thiazide diuretics (TD) on calcitropic hormones and biochemical bone markers.

DESIGN

A total of 50 postmenopausal women were randomized to 7 days of treatment with either the TD bendroflumethiazide, the LD bumetanide, bendroflumethiazide plus bumetanide, or placebo. Blood and urine (24 h) were sampled on each day. Statistical inferences were made versus the concomitant changes in the placebo group.

RESULTS

Bendroflumethiazide increased the tubular reabsorption of calcium (TRCa) (+0.46 +/- 0.11%, P=0.009), plasma levels of parathyroid hormones (PTH) (+24 +/- 10%, P=0.06), and 1,25(OH)2D (+12 +/- 6%, P=0.03). Bumetanide decreased the TRCa (-0.5 +/- 0.1%, P=0.01) and increased plasma PTH and 1,25(OH)2D levels (+27 +/- 9%, P=0.02 and +36 +/- 12%, P=0.006, respectively). Treatment with either of the drugs did not alter plasma calcium, osteocalcin, bone alkaline phosphatase (bone-ALP) or urinary NTx/creatinine ratio. However, treatment with both drugs caused an increased plasma calcium level (+2.7 +/- 1.0%, P=0.007) and decreased plasma levels of bone-ALP (-21 +/- 3%, P=0.001), osteocalcin (-6 +/- 3%, P=0.03), and urinary NTx/creatinine ratio (-39 +/- 6%, P=0.001).

CONCLUSION

Calcium homeostasis and bone metabolism are to a major degree influenced by diuretic treatment. Surprisingly, LD and TD exerted a similar effect on calcitropic hormones despite their opposite effects on the renal calcium excretion. In clinical practice, treatment with diuretics has to be considered as a cause of parathyroid stimulation.

Diuretic complications

BACKGROUND

Diuretics are widely used and generally safe, but like any therapeutic agents, they may cause side effects.

METHODS

A review of recent literature pertaining to diuretic usage was performed, with emphasis on specific reports of side effects. Reports of large-scale hypertension trials employing diuretics were also examined for descriptions of diuretic-related complications.

RESULTS

All diuretics promote excretion of sodium. Depending upon the site and mode of action, some diuretics increase excretion of potassium, chloride, calcium, bicarbonate, or magnesium. Some can reduce renal excretion of electrolyte-free water, calcium, potassium, or protons. Consequently, electrolyte and acid-base disorders commonly accompany diuretic use. Except for the mildly natriuretic collecting duct agents, which are used mainly to limit potassium excretion, all diuretics can cause volume depletion with prerenal azotemia. Loop agents and distal convoluted tubule agents, such as the thiazides, produce hypokalemic, hypochloremic, metabolic alkalosis that responds to potassium chloride replacement. Carbonic anhydrase inhibitors produce less hypokalemia and volume depletion but commonly induce metabolic acidosis that is often symptomatic. The potassium-sparing agents also limit proton excretion, and spironolactone may produce metabolic acidosis. Hyperkalemia is a leading complication of the potassium-sparing agents, especially in patients with an underlying tendency for hyperkalemia. Thiazide diuretics, in particular, have been linked to glucose intolerance, which may be an effect of hypokalemia rather than the diuretic itself. Whether diuretic-induced hypokalemia increases cardiovascular risk is controversial. Loop agents and thiazides may lead to hyponatremia, which, in the case of thiazides, may cause permanent neurologic damage. Dose-related reversible or irreversible ototoxicity may complicate treatment with loop agents. Nephrocalcinosis, nephrolithiasis, hypomagnesemia, and hyperuricemia can potentially complicate treatment with some diuretic agents. Reported idiosyncratic reactions to diuretics include interstitial nephritis, noncardiogenic pulmonary edema, pancreatitis, and myalgias.

CONCLUSIONS

Potential side effects of a diuretic can often be anticipated from its mode of action on the kidney. These complications may be mitigated with careful monitoring, dosage adjustment, and replacement of electrolyte losses. Other side effects are idiosyncratic and cannot be prevented.

Impact of antihypertensive treatment on quality of life: comparison between bisoprolol and bendrofluazide

OBJECTIVES

To compare quality of life with the selective beta1-blocker bisoprolol and the thiazide diuretic bendrofluazide in patients with mild to moderate hypertension.

DESIGN AND SETTING

Multi centric, randomised, double-blind, two-way crossover study carried out at six general practice centres.

SUBJECTS

Eighty-one patients with newly diagnosed or previously treated hypertension, who had a mean diastolic blood pressure (BP) of 95-120 mm Hg after receiving placebo for 4-6 weeks.

INTERVENTIONS

In random order, patients received bisoprolol (5 mg once daily) or bendrofluazide (2. 5 mg once daily) for 8 weeks.

MAIN OUTCOME MEASURES

Quality of life and antihypertensive effect.

RESULTS

Decrease in systolic/diastolic BP did not differ between bisoprolol (10 +/- 2/13 +/- 1 mm Hg) and bendrofluazide (9 +/- 2/11 +/- 1 mm Hg). Between bisoprolol and bendrofluazide neither in the intention-to-treat nor in the efficacy analysis any difference was found in quality of life variables, such as Health Status Index, somatic symptoms, anxiety, depression, total psychiatric morbidity, cognitive symptoms and hostility score. Compared to baseline the Health Status Index improved (P < 0.05) during bisoprolol. None of the other investigated quality of life variables changed compared to baseline. No patients dropped out during bisoprolol or bendrofluazide treatment. Although, the total number of reported adverse events appeared lower during bendrofluazide than during bisoprolol treatment, it is unclear whether drug related adverse events also differ between the two drugs.

CONCLUSIONS

At equipotent antihypertensive dosages, the effect of an 8-week treatment on quality of life does not differ between the selective beta1-blocker bisoprolol and the thiazide diuretic bendrofluazide.

Lichen planus associated with milia

The formation of milia is well recognized in both bullous and inflammatory dermatoses. There are several reports of milia developing in a rare variant of lichen planus pilaris known as lichen planus follicularis tumidus (LPFT), but the association of milia with other types of lichen planus (LP) has not been documented in the literature. We report five patients who developed milia during the course of either drug-induced or idiopathic LP and one in whom milia developed in a lichenoid tattoo reaction. Milia were noted to occur transiently during the resolving phase of LP. Most cases were severe enough to warrant treatment with systemic steroids. The association of milia with LP is not restricted to the rare clinical variant LPFT. We speculate that a severe lichenoid reaction with basal layer degeneration may precipitate the formation of milia in some cases of LP.

A randomised double-blind study comparing nifedipine GITS 20 mg and bendrofluazide 2.5 mg administered once daily in mild-to-moderate hypertension

A multicentre, randomised, double-blind, parallel group comparison of nifedipine GITS 20 mg (Adalat LA) once daily and bendrofluazide 2.5 mg once daily in patients with mild-to-moderate hypertension was conducted. Two hundred patients with a diastolic blood pressure (BP) in the range 95 to 109 mm Hg were randomised to active treatment for 6 weeks. For the per-protocol efficacy population, both treatments resulted in clinically significant mean reductions of trough diastolic BP (nifedipine GITS -8.9 mm Hg, bendrofluazide -7.9 mm Hg) and systolic BP (nifedipine GITS -10.4 mm Hg, bendrofluazide -10.5 mm Hg). The study demonstrated that nifedipine GITS was 'at least equivalent' to bendrofluazide in the reduction of trough diastolic BP (one-sided upper 95% confidence limit, 0.5 mm Hg), where inequivalence had been pre-defined as a difference in mean diastolic BP of > or =5 mm Hg. Both drugs were well tolerated, the overall incidence of adverse events in the nifedipine GITS treatment group being 34.0% (34/100) and in the bendrofluazide treatment group being 29.0% (29/100). The commonest events (incidence > or =5%) were headache, constipation, 'flu syndrome and vasodilatation with nifedipine GITS and headache and nausea with bendrofluazide. An increased incidence of elevations of plasma urea and glucose was observed in patients treated with bendrofluazide (9.6% and 30.4% respectively) compared to those treated with nifedipine GITS (3.1% and 18.8% respectively). Nifedipine GITS 20 mg once daily is 'at least equivalent' to bendrofluazide 2.5 mg once daily in reduction of blood pressure in patients with mild-to-moderate hypertension.

Effects of combination therapy with an angiotensin converting enzyme inhibitor and thiazide diuretic on insulin action in essential hypertension

OBJECTIVE

To determine whether combination of an angiotensin converting enzyme inhibitor with a high dose of thiazide diuretic avoids adverse metabolic consequences of thiazide diuretics.

DESIGN

Double-blind randomized crossover study of two 12-week treatment periods with captopril (up to 100 mg/day) either alone or in combination with 5 mg bendrofluazide given after a 6-week placebo run-in period. Treatment periods were separated by a 6-week placebo washout period.

SETTING

Outpatient clinics in greater Belfast.

PATIENTS

Fifteen white non-diabetic essential hypertensives (seven male) aged < 65 years recruited from general practices in greater Belfast.

MAIN OUTCOME MEASURES

Systolic and diastolic blood pressures and peripheral and hepatic insulin action.

RESULTS

Two patients failed to complete the study. Blood pressure was lowered (139/89+/-18/7 mmHg combination versus 160/97+/-21/7 mmHg captopril; P < 0.001). Fasting insulin level was raised (7.9+/-3.6 mU/l combination versus 6.2+/-3.2 mU/l baseline; P < 0.001). There were no differences between treatments for glucose, urate, cholesterol and triglyceride levels. Serum potassium level was lowered (3.8+/-0.4 mmol/l combination versus 4.2+/-0.4 mmol/l captopril, P < 0.05). Postabsorptive endogenous glucose production was raised (10.8+/-1.7 micromol/kg per min combination versus 10.0+/-1.5 micromol/kg per min captopril; P < 0.01) and was greater than baseline (9.7+/-2.1 micromol/kg per min, P < 0.05). Suppression of glucose production by insulin was similar with both treatments. Exogenous glucose infusion rates required to maintain euglycaemia did not differ (32.4+/-7.6 micromol/kg per min captopril, 32.7+/-6.2 micromol/kg per min combination, 31.5+/-7.2 micromol/kg per min baseline).

CONCLUSIONS

Combination therapy increased glucose production (compared with captopril alone), indicating hepatic insulin resistance. It cannot be assumed that combined preparations with angiotensin converting enzyme inhibitors will ameliorate adverse effects of high doses of thiazide diuretics on insulin action.

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.

Lithium toxicity

We report a case of severe lithium toxicity precipitated by a thiazide diuretic and compounded by an angiotensin converting enzyme inhibitor. There was severe vasodilatation refractory to noradrenaline.

Central effects of the diuretic, bendrofluazide

1. Central effects of the diuretic, bendrofluazide (2.5, 5 and 10 mg) were studied in 12 healthy volunteers. Two placebos and an active control drug, oxazepam (15 mg), were included. Single doses were administered double-blind at 10.00 h. The effects of drugs on performance and subjective feelings were assessed before and from 1.5-2.5 and 3.5-4.5 h after ingestion, and recording of the electrical activity of the brain (EEG) and body sway carried out. 2. Performance was assessed using digit symbol substitution, continuous attention, letter cancellation, choice reaction time, finger tapping, immediate and short-term memory, together with critical flicker fusion and two flash fusion. Subjects assessed their mood and well-being on a series of 12 visual analogue scales. The EEG was recorded with eyes open while the subjects carried out a mental arithmetic task, and with eyes closed, when they were required to relax. Body sway was recorded with eyes open and with eyes closed. 3. Bendrofluazide (10 mg) increased the number of errors at letter cancellation and reduced the rate of finger tapping (P < 0.05), while oxazepam increased the number of errors and reduced accuracy at continuous attention (P < 0.01), and increased the number of involuntary rest pauses during tapping (P < 0.05). 4. There were no effects of drugs on subjective assessment of mood. 5. No changes in the electrical activity of the brain were observed with bendrofluazide. In recordings with eyes open, oxazepam reduced delta (0.5-3 Hz), theta (3.5-7 Hz) and alpha 2 (10.5-13 Hz) while increasing beta 1 (13.5-21 Hz) activity.(ABSTRACT TRUNCATED AT 250 WORDS)

A double-blind trial of captopril or bendrofluazide in newly diagnosed senile hypertension

Hypertension is a major risk factor for stroke and heart disease in the elderly. Eighty-one hypertensive subjects with mild cognitive impairement, aged over 70 years, were drawn from a community screening programme and randomized to either 12.5 mg captopril twice daily or 2.5 mg bendrofluazide daily in a double-blind trial. Subjects were excluded if they had previously received antihypertensive treatment. The mean blood pressure was reduced from 193/101 mmHg to 154/87 mmHg by captopril and from 188/102 mmHg to 151/89 mmHg by bendrofluazide after 24 weeks; there was no significant difference between the two drugs. Seven subjects withdrew due to adverse events. Adverse events occurred more frequently during the 2-week placebo phase than during active treatment with either drug. The only significant detrimental changes in pre-existing conditions were in 3 subjects (2 captopril, 1 bendrofluazide) who were noted to have worsening of their cataracts. One subject on captopril and 4 subjects on bendrofluazide became hypokalaemic. The trial results support the use of captopril as an alternative to bendrofluazide as a first-line antihypertensive agent in the community for elderly people, but large studies are required to measure accurately effects on significant morbidity and mortality.

Central effects of combined bendrofluazide and atenolol administration. A single dose study in normal subjects

Twelve normal male subjects received single oral doses of atenolol 100 mg (AT), bendrofluazide 5 mg (BFZ), combined atenolol 100 mg and bendrofluazide 5 mg (AT/BFZ), diazepam 5 mg (Dz), or one of two matching placebos, on each of 6 study days. Tests of psychomotor performance [digit symbol substitution (DSST), letter cancellation (LCT), continuous attention, choice reaction time (CRT), finger tapping, short-term memory, body sway], physiological measurements [critical flicker fusion (CFF), two-flash fusion (2FF)] and subjective assessments using visual analogue scales (VAS), were performed at 2 and 4 hours post-ingestion. Dz (active control) significantly worsened VAS scores at 2 h (+0.68) and reduced DSST scores at both 2 h (-15.0) and 4 h (-11.0). AT and BFZ given alone, each produced significant worsening of VAS at 2 h [AT +1.0; BFZ +1.38], but had no significant effects on performance. In combination however, AT/BFZ at 4 h produced significant impairment of DSST scores (-10.4), reduced finger tapping (-16.5) and increased involuntary rest pauses (+16.5). Despite these effects, no change in VAS scores occurred. In summary, we have demonstrated significant impairment of psychomotor performance in normal subjects with the AT/BFZ combination, which was not evident with the single agents and which occurred in the absence of a change in subjective awareness. These central effects may have important clinical implications for patients taking combined antihypertensive medication.

Hypertensive Old People in Edinburgh (HOPE) Study: electrocardiographic changes after captopril or bendrofluazide treatment

Hypertension is a major risk factor for stroke and heart disease in elderly people. Eighty hypertensive subjects with mild cognitive impairment, aged over 70 years were drawn from a community screening programme and randomized to either captopril 12.5 mg twice daily or bendrofluazide 2.5 mg daily in a double-blind trial. Subjects were excluded if they had previously received antihypertensive treatment or had significant cardiac disease. Electrocardiograms (ECG) were recorded and scored at baseline and after 12 and 24 weeks of treatment. Mean blood pressure fell significantly and equally in both treatment groups. Most ECG variables remained unchanged throughout the trial but a significant reduction in QRS duration from 0.08 to 0.07 seconds was observed with captopril at 12 weeks (p = 0.004) and 24 weeks (p = 0.002). Subjects on captopril also exhibited a significant improvement in overall ECG classification at 12 weeks (p < 0.05), although this was not sustained at 24 weeks (p = 0.076). Captopril is a suitable alternative to bendrofluazide as an antihypertensive drug for elderly people with regard to ECG detected cardiac complications.

Thiazide-induced kidney damage with circulating antibodies against myeloperoxidase and cardiolipin

A 79-year-old man developed a renal insufficiency while on thiazide. Extrarenal symptoms were absent. Screening for antibodies revealed high titre for anti-myeloperoxidase and anti-cardiolipin antibodies, but no other antibodies were present. After withdrawal of the drug the progression of renal insufficiency ceased. Four months later the both antibodies had disappeared. We conclude, that antibodies against granulocytes will become a valuable diagnostic tool in diagnosing drug-induced vasculitis.

[The combination of ACE inhibitor and thiazide may cause severe hyponatremia]

A case of a woman aged 79 years presenting severe hyponatraemia is described. The patient was not dehydrated and the urine was hypertonic. There was no history of renal, hepatic or cardiac disorders. Some weeks previously she had been treated with lisinopril and bendroflumethiazide on account of arterial hypertension. After withdrawal of the drugs and intensive therapy the patient recovered rapidly. The combination of an ACE-inhibitor and a thiazide drug may lead to serious disturbances in body fluid compartments and serum electrolytes. The need for frequent control of serum electrolytes is emphasized.

Oral mucosal friction and subjective perception of dry mouth in relation to salivary secretion

Assessment of oral mucosal friction and subjective perception of dry mouth was performed during treatment with thiazide diuretic bendroflumethiazide (2.5 mg o.d.) or placebo in a randomized, double-blind, cross-over study (2 x 2 wk) in 34 healthy volunteers. Treatment with bendroflumethiazide was associated with a 10% reduction in the stimulated whole saliva secretion rate and a 15% reduction in the salivary sodium concentration, as compared with placebo. Oral mucosal friction was concomitantly measured on the buccal mucosa and on the mucosa of the lower lip by means of a newly developed sliding friction device. In addition, a questionnaire was used to evaluate how the treatment was subjectively perceived with regard to symptoms of dry mouth. Mucosal friction of the lower lip increased significantly during treatment with bendroflumethiazide, as compared with placebo. When the test subjects, regardless of pharmacologic treatment, were divided into groups according to subjective perception of dry mouth, the dry mouth group showed significantly lower resting and stimulated flow rate and higher mucosal friction in comparison to the nondry group. When, in addition, pharmacologic treatment was also considered, the differences between the dry and the nondry group were restricted to resting whole saliva flow rate and mucosal friction during bendroflumethiazide treatment. It is concluded that resting whole saliva flow rate is the best predictive factor for evaluating subjectively perceived dry mouth. However, the sensitivity of the developed sliding friction device is capable of detecting minor changes in salivary secretion rate. In addition, measurements of oral mucosal friction may serve as an easily available method to complement sialometry when evaluating, for example, drug-induced dryness of the mouth.

Aging and susceptibility to drug-induced orthostatic hypotension

OBJECTIVE

To test the hypothesis that the short-term effect of transbuccal nitroglycerin (glyceryl trinitrate, 0.0625 to 1.5 mg) on orthostatic cardiovascular responses would predict the effect of a diuretic (5 mg bendroflumethiazide daily for 1 week), particularly in elderly subjects who may be at higher risk for orthostatic hypotension.

METHODS

This was a randomized crossover study. Participants were 17 elderly (age range, 63 to 84 years) and 15 younger (age range, 19 to 35 years) healthy ambulant volunteers. Interventions and measures of outcome included blood pressure (BP; in millimeters of mercury) and heart rate (HR; in beats per minute) changes with standing, which were measured before administration of medication and after each drug treatment.

RESULTS

Subjects in the elderly and younger groups had different BP and HR changes (mean percentage change) at 1 minute after standing in all three study phases (unmedicated, elderly: BP, -4%/+1%; HR, +12%; young: BP, +2%/+12%; HR, +27%; p = 0.06 for BP, p less than 0.01 for HR; bendroflumethiazide, elderly: BP, -9%/-3%; HR, +17%; young: BP, +1%/+11%; HR, +33%; p less than 0.05 for all; nitroglycerin (0.25 mg), elderly: BP, -15%/-12%; HR, +21%; young: BP, -6%/+7%; HR, +38%; p less than 0.05 for all). The incremental orthostatic effects of the two drugs were similar in the two age groups and were positively correlated (r = 0.65, p less than 0.001) in individual subjects.

CONCLUSIONS

Individual susceptibility to drug-induced orthostatic hypotension depends on a combination of the age-related unmedicated orthostatic response and the additional drug effect, which is independent of age. The BP response to standing after administration of nitroglycerin may be useful in predicting the effect of other drugs known to influence orthostatic BP control.

A double-blind crossover study of the effect of concomitant diuretic therapy in hypertensive patients treated with amlodipine

Twelve patients with essential hypertension who were already on treatment with the long-acting calcium antagonist amlodipine (5 mg once daily) were entered into a double-blind, randomized crossover study of the addition of one month's treatment with either bendrofluazide (5 mg once daily) or matching placebo. The addition of bendrofluazide did not cause any statistically significant fall in the supine blood pressure compared to treatment with placebo (147.6/90.1 +/- 4.8/2.8 v 150.8/92.6 +/- 4.3/2.3 mm Hg, respectively). Plasma potassium was significantly lower on bendrofluazide as compared to placebo (3.11 +/- 0.14 v 3.62v +/- 0.13 mmol/L, P less than .001) and 10 of 12 patients had a fall in plasma potassium while on diuretic. The results of this study suggest that a thiazide diuretic has little additive effect on blood pressure in patients already on the long-acting dihydropyridine amlodipine, and may cause hypokalemia.

Hypokalemic and ECG sequelae of combined beta-agonist/diuretic therapy. Protection by conventional doses of spironolactone but not triamterene

Salbutamol (Albuterol) and diuretics are commonly prescribed together in patients with airflow obstruction and are associated with electrocardiographic effects. We have now investigated whether the use of potassium-sparing drugs might prevent the ECG sequelae of such combined therapy. Ten healthy subjects received seven days of randomized treatments with: placebo, bendrofluazide (5 mg), bendrofluazide plus triamterene 50 mg (conventional dose), or triamterene 200 mg (high dose), and bendrofluazide plus spironolactone (100 mg). Potassium and ECG responses to inhaled salbutamol, 2 mg, were measured after each treatment period. The T-wave flattening in response to bendrofluazide and salbutamol (0.24[CI, 0.19 to 0.29]mV) was attenuated by the addition of triamterene, 200 mg (0.33[CI, 0.28 to 0.37]mV; p less than 0.05) and spironolactone 100 mg (0.42[CI, 0.37 to 0.47]mV; p less than 0.01), but not by triamterene 50 mg (0.25[CI, 0.20 to 0.30]mV). Spironolactone and high dose triamterene also diminished the frequency of U waves and ST depression. The ECG effects mirrored hypokalemic responses which were also blunted by high dose (p less than 0.01) but not low dose triamterene, as well as by spironolactone (p less than 0.001). Thus, the use of high dose triamterene and spironolactone protected against the hypokalemic and ECG sequelae of combined beta-agonist/diuretic therapy, whereas a conventional dose of triamterene had no effect. These findings may be important in the prevention of a potentially dangerous interaction in susceptible patients taking this combination of drugs.

Grinspan's syndrome: a drug-induced phenomenon?

Three cases of apparently drug-induced Grinspan's syndrome involving the triad of oral lichen planus, diabetes mellitus, and hypertension are reported. Because drug therapy for diabetes mellitus and hypertension is capable of producing lichenoid reactions of the oral mucosa, the question arises as to whether Grinspan's syndrome is an iatrogenically induced syndrome.