Modamide

Potassium- conserving agent;diuretic.

Although Modamide Hydrochloride may be used alone, its principal indication is as concurrent therapy with thiazides or more potent diuretics in order to conserve potassium during periods of vigorous diuresis and during long-term maintenance therapy.

In congestive heart failure, Modamide Hydrochloride may be effective alone, but its principal indication is for concomitant use in patients receiving thiazides or more potent diuretic agents.

In hypertension, it is used as an adjunct to prolonged therapy with thiazides and similar agents to prevent potassium depletion.

In hepatic cirrhosis with ascites, Modamide Hydrochloride usually provides adequate diuresis, with diminished potassium loss and less risk of metabolic alkalosis, when used alone. It may be used with more potent diuretics when a greater diuresis is required while maintaining a more balanced serum electrolyte pattern.

Adults

Modamide Hydrochloride alone.The initial dosage is 10 mg (as a single dose or 5mg twice a day). The total daily dose should not exceed 20mg (4 tablets) per day. After diuresis has been achieved, the dosage may be reduced by 5mg increments to the least amount required.

Modamide Hydrochloride with other diuretic therapy

When Modamide is used with a diuretic which is given on an intermittent basis, it should be given at the same time as the diuretic.

Hypertension

Usually half 'Modamide' tablet (2.5mg) given once a day together with the usual antihypertensive dosage of the thiazide concurrently employed. If necessary, increase to 5mg (one 'Modamide' tablet) given once a day or in divided doses.

Congestive heart failure

Initially half 'Modamide' tablet (2.5mg) a day together with the usual dosage of the diuretic concurrently employed, subsequently adjusted if required, but not exceeding two 'Modamide' tablets (10mg) a day. Optimal dosage is determined by diuretic response and the plasma potassium level. Once an initial diuresis has been achieved, reduction in dosage may be attempted for maintenance therapy. Maintenance therapy may be on an intermittent basis.

Hepatic cirrhosis with ascites

Treatment should be started with a low dose of Modamide, i.e. 5mg (1 tablet), plus a low dosage of the other diuretic agent. If necessary, dosage of both agents may be increased gradually until there is effective diuresis.

The dosage of Modamide should not exceed two 'Modamide' tablets (10 mg) a day. Maintenance dosages may be lower than those required to initiate diuresis; reduction in the daily dosage should therefore be attempted when the patient's weight is stabilised. Gradual weight reduction in cirrhotic patients is especially desirable to reduce the likelihood of untoward reactions associated with diuretic therapy.

Elderly

The elderly are more susceptible to electrolyte imbalance and are more likely to experience hyperkalaemia since renal reserve may be reduced. The dosage should be carefully adjusted according to renal function, blood electrolytes and diuretic response.

Children:

The use of Modamide in children under 18 years of age is not recommended as safety and efficacy have not been established.

Hyperkalaemia (plasma potassium over 5.5mmol/l), other potassium conserving agents or potassium supplements (see precautions); Addison's disease; anuria, acute renal failure, severe progressive renal disease, diabetic nephropathy (see Precautions); prior sensitivity to this product. Safety for use in children is not established. See also 'Use in pregnancy' and 'Use in the breast feeding mother'.

Diabetes Mellitus: To minimise the risk of hyperkalaemia in known or suspected diabetic patients, the status of renal function should be determined before initiating therapy. Modamide hydrochloride should be discontinued for at least three days before a glucose tolerance test.

Metabolic or Respiratory Acidosis: Potassium-conserving therapy should be initiated only with caution in severely ill patients in whom metabolic or respiratory acidosis may occur, e.g. patients with cardiopulmonary disease or decompensated diabetes.

Shifts in acid-base balance alter the balance of extracellular-intracellular potassium and the development of acidosis may be associated with rapid increases in plasma potassium.

Hyperkalaemia: This has been observed in patients receiving Modamide Hydrochloride, alone or with other diuretics, These patients should be observed carefully for clinical, laboratory and ECG evidence of hyperkalaemia.

Some deaths have been reported in this group of patients, Hyperkalaemia has been noted particularly in the elderly and in hospital patients with hepatic cirrhosis or cardiac oedema who have known renal involvement who were seriously ill, or were undergoing vigorous diuretic therapy.

Neither potassium-conserving agents nor a diet rich in potassium should be used with Modamide except in severe and/or refractory cases of hypokalaemia, If the combination is used, plasma potassium levels must be continuously monitored.

Impaired renal function: Patients with increases in blood urea over 10 mmol/l, serum creatinine over 130 µmol/l, or with diabetes mellitus, should not receive Modamide Hydrochloride without careful frequent monitoring of serum electrolytes and blood urea levels. In renal impairment, use of a potassium-conserving agent may result in rapid development of hyperkalaemia.

Treatment of Hyperkalaemia

If hyperkalaemia occurs, Modamide hydrochloride should be discontinued immediately and, if necessary, active measures taken to reduce the plasma potassium level.

Electrolyte imbalance and Reversible blood urea increases: Hyponatraemia and hypochloraemia may occur when Modamide Hydrochloride is used with other diuretics. Reversible increases in blood urea levels have been reported accompanying vigorous diuresis, especially when diuretics were used in seriously ill patients, such as those with hepatic cirrhosis with ascites and metabolic alkalosis, or those with resistant oedema. Careful monitoring of serum electrolytes and blood urea levels should therefore be carried out when Modamide is given with other diuretics to such patients.

Cirrhotic patients: Oral diuretic therapy is more frequently accompanied by side effects in patients with hepatic cirrhosis with or without ascites, because these patients are intolerant of acute shifts in electrolyte balance, and because they often already have hypokalaemia as a result of associated aldosteronism.

In patients with pre-existing severe liver disease, hepatic encephalopathy manifested by tremors, confusion, coma and increased jaundice, has been reported in association with diuretics, including Modamide hydrochloride.

Reduced mental alertness may impair ability to drive or operate dangerous machinery.

Modamide Hydrochloride is normally well tolerated, although minor side effects are reported relatively frequently. Except for hyperkalaemia, significant side effects are infrequent. Nausea, anorexia, abdominal pain, flatulence and mild skin rashes have been reported and are probably related to Modamide: but other side effects are generally associated with diuresis, or with the underlying disease being treated.

Body as a whole: Headache, weakness, fatigue, back pain, chest pain, neck/shoulder ache, pain in extremities.

Cardiovascular: Angina pectoris, orthostatic hypotension, arrhythmias, palpitation, one patient with a partial heart block developed complete heart block.

Digestive: Anorexia, nausea, vomiting, diarrhoea, constipation, abdominal pain, GI bleeding, jaundice, thirst, dyspepsia, flatulence.

Metabolism and nutrition disorders

Elevated plasma potassium levels above 5.5mmol/l, hyponatraemia. Serum uric acid levels may rise during treatment with Modamide and acute attacks of gout may be precipitated.

Integumentary : Pruritus, rash, dryness of mouth, alopecia.

Musculoskeletal: Muscle cramps, joint pain, Serum uric acid levels may rise during treatment with Modamide and acute attacks of gout may be precipitated.

Nervous: Dizziness, vertigo, paraesthesia, tremors, encephalopathy.

Psychiatric: Nervousness, mental confusion, insomnia, decreased libido, depression, somnolence.

Respiratory : Cough, dyspnoea.

Special senses: Nasal congestion, visual disturbances, increased intra ocular pressure, tinnitus.

Urogenital: Impotence, polyuria, dysuria, bladder spasms, frequency of micturition.

Reactions in which no causal relationship could be established were activation of probable pre-existing peptic ulcer, aplastic anaemia, neutropenia and abnormal liver function tests. In a few cirrhotic patients, jaundice associated with the underlying disease had deepened, but the drug relationship is uncertain.

Reporting of suspected adverse reactions

Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme; website: www.mhra.gov.uk/yellowcard

No data are available; and it is not known whether the drug is dialysable.

The most likely signs and symptoms are dehydration and electrolyte imbalance which should be treated by established procedures. Therapy should be discontinued and the patient observed closely. No specific antidote is available. If ingestion is recent, emesis should be induced or gastric lavage should be performed.

Treatment is symptomatic and supportive. If hyperkalaemia occurs, active measures should be taken to reduce plasma potassium levels.

The plasma half life of Modamide is about six hours.

Pharmacotherapeutic group: Other Potassium sparing agents,

ATC code: C03DB01

Modamide hydrochloride is a diuretic.

Absorption

Modamide is incompletely absorbed from the gastrointestinal tract.

Distribution

Peak serum concentrations are achieved about 3-4 hours after administration by mouth.

Elimination

It is excreted unchanged in the urine. Modamide has been estimated to have a serum halflife of about 6 hours.

None stated

Not applicable