Evaluation of a fixed combination of timolol maleate, hydrochlorothiazide and amiloride hydrochloride in the treatment of hypertension: A long-term multicentre trial

The effect of a single daily dose of timolol, hydrochlorothiazide and amiloride hydrochloride in fixed combination (Moducren; MDS) in patients with mild to moderate essential hypertension was tested during 1978 in an open study covering 10 weeks per patient. This was subsequently extended to cover a total of 50 weeks per patient, and the results are compared. Of the patients studied during phase 1, 91,5% responded with a fall in diastolic blood pressure of 10 mmHg or more. This figure decreased to 87,5% during phase 2, but none the less remained satisfactory. A single daily dose of one tablet or less of the trial preparation proved effective in the majority of patients (75%). Adverse effects were infrequent and usually of a minor nature.

Combination of timolol maleate, hydrochlorothiazide and amiloride hydrochloride in the treatment of hypertension: A multicentre trial

The effect of a single dose of timolol, hydrochlorothiazide and amiloride in fixed combination (Moducren; MSD) in patients with mild to moderate essential hypertension was tested in an open study during 1978. Ninety-one and a half per cent of the patients studied responded with a fall in diastolic blood pressure of 20 mmHg or more. In 72% a single daily tablet of the combined preparation was sufficient to achieve and maintain control. Patient compliance was excellent and adverse reactions were generally of a minor nature.

Moduretic-induced metabolic acidosis and hyperkalaemia

A patient who developed significant metabolic acidosis and severe hyperkalaemia while taking Moduretic (amiloride and hydrochlorothiazide) is reported. During the period of hyperkalaemia (maximum potassium 7-6 mmol/l) the patient's whole body potassium content was normal. His acid-base balance and serum potassium returned to normal some 10 days after stopping the drug. The possible mechanism of acidosis and hyperkalaemia in this patient is discussed.

Effects of amiloride on arterial pressure and renal function

Amiloride was administered to 13 male patients with mild essential hypertension and normal renal function. It effectively reduced supine and standing arterial pressures. The antihypertensive response was associated with a significant decrease in renal inulin clearance and a rise in plasma creatinine concentration, although both values at the end of seven weeks of therapy remained within normal limits. Serum potassium concentrations rose but did not reach hyperkalemic levels. Amiloride did not increase blood levels of glucose, uric acid, lipids, calcium, or urea nitrogen. We conclude that amiloride is an effective antihypertensive and antikaliuretic agents for patients with mild hypertension and normal renal function.

Plasma potassium levels in hypertensive patients receiving fixed-combination diuretic therapy

Among 54 patients attending a hospital hypertension clinic and receiving the fixed-combination diuretic Moduretic (hydrochlorothiazide 50 mg, amiloride 5 mg), there was a 44.4% incidence of hypokalaemia. The mean drop in plasma potassium level was 0.69 mmol/L (P less than 0.0001), the mean low level being 2.81 mmol/L. Seventy-four per cent of falls occurred within 52 weeks of the start of therapy, 19.5 weeks being the average period between a normal and a low plasma potassium level. There was no difference in the fall in potassium level between male and female subjects, and beta-blockers were not obviously protective, although there was a statistically significant smaller fall in potassium level in females treated with them. The clinical significance of the unexpected hypokalaemia is uncertain; but even with fixed-combination diuretics, it remains necessary to monitor the plasma potassium level regularly in order to avoid complicating situations. The results of the present study would cast doubt on the efficacy of 5 mg of amiloride with 50 mg of hydrochlorothiazide in fixed-combination form in preventing hypokalaemia in this clinical situation.

Amiloride, spironolactone, and potassium chloride in thiazide-treated hypertensive patients

Dose-response curves for amiloride and spironolactone were defined in 15 hypertensive patients treated with bendroflumethiazide (bendrofluazide). The relative potency amiloride:spironolactone in correcting hypokalemia was 2.8:1, an estimate significantly lower than the 5:1 potency currently accepted. The relative potency for reduction of plasma sodium was 3.9:1 (amiloride:spironolactone). Amiloride was disproportionately potent in lowering serum bicarbonate, and the data do not suggest that these drugs elevate plasma potassium simply by correcting metabolic alkalosis. Changes in blood pressure were confounded by the presence of carryover effect between treatment phases. Both drugs increased plasma angiotension II and aldosterone, but the rise in aldosterone with spironolactone was smaller than expected from concurrent plasma angiotension II and potassium concentrations. This was consistent with a partial block of aldosterone biosynthesis by spironolactone. The activity of spironolactone did not require the presence of hyperaldosteronism. In a smaller study potassium chloride induced a significant log dose-response on plasma potassium, but the effect was small in absolute terms. At least 64 mmole potassium chloride was needed to match the effect of 20 mg amiloride or 56 mg spironolactone.

Total body potassium and long-term treatment with amiloride HCL and/or hydrochlorothiazide

The potassium sparing effect of 5 mg of amiloride (A) given either alone, or in combination with 50 mg of hydrochlorothiazide (HCTH) was evaluated in 23 patients with essential hypertension on a daily diet containing 70 mEq of K and 130 mEq of Na. Two studies were carried out. In the first, patients received HCTH alone (2 months) followed by A alone (2 months) and the two combined (6 months). The results of this study demonstrate that A is capable of correcting and preventing the loss of serum and total body potassium (TBK) and of reducing the increase of serum uric acid induced by HCTH. In the second study, each patient received from the beginning A + HCTH for 12 months; no statistically significant changes for serum and total body potassium and for serum uric acid appeared in any patient after six and twelve months. This study proves that A is capable of clinical potassium sparing effect in hypertensives and that this effect is a long lasting one.

Severe hyperkalaemia with Moduretic

Three patients with impaired renal function suffered complications of hyperkalaemia within 10 days of beginning therapy with hydrochlorothiazide and amiloride combination (Moduretic). The possible relationship between hyperkalaemia and this diuretic is discussed.

[Results of a national therapeutic trial in 10,000 hypertensive patients conducted by 2000 general practitioners (author's transl)]

Multicenter study in 10294 hypertensive patients conducted by 2000 G.P.'s throughout France. This trial permitted to compare the effectiveness and tolerance of 3 types of antihypertensive therapy: a beta-blocker, a diuretic and a central antihypertensive agent. It also permitted to study a certain number of socio-epidemiological characteristics in that patient population, in particular with regard to cardio-vascular risk factors.

Concomitant administration of timolol and hydrochlorothiazide/amiloride in hypertensive patients. Results of a titration study

In an open dose titration study we evaluated the antihypertensive effect of the concomitant administration of timolol and hydrochlorothiazide/amiloride, administered on a b.i.d. basis. Twenty-eight out of 39 patients completed the study. Supine and standing systolic and diastolic blood pressures and pulse rate were significantly lower at the end of the titration period than at the end of the diuretic period.

[Controlled clinical research on the potassium-retaining action of various diuretic drugs]

The potassium-retaining action was evaluated in its kaliemic reflexes, in two diuretic associations composed respectively of hydrochlorothiazide + spironolactone and hydrochlorothiazide + amiloride. The potassium intraerythrocytic levels were also determined as well as the natriuresis, the natremia and the daily diuresis. Researches carried out on a group of patients affected by congestive heart failure showed that, the diuretic efficacy being equal, the association of hydrochlorothiazide + spironolactone does not significantly interfere, at the various posologic levels, with the potassium balance. On the contrary, in this regard, the associaiton of amiloride + hydrochlorothiazide appeared to be less manageable because therapeutic dosages showed a tendency to hyperdaliemia.