Losartan Potassium/Hydrochlorothiazide 50mg /12.5mg Tablets
rr
Summary of Product Characteristics of Losartan potassium and Hydrochlorothiazide 50mg/12.5mg
Tablets
l
1. NAME OF THE MEDICINAL PRODUCT
Losartan potassium and Hydrochlorothiaizde 50mg/12.5mg Tablets.
2. QUALITATIVE AND QUANTITATIVE COMPOSITION
The active ingredients are losartan potassium and hydrochlorothiazide.
Each Losartan potassium and Hydrochlorothiazide 50mg/12.5mg Tablet contains 45.8 mg of Losartan, present as 50 mg of Losartan Potassium, and 12.5 mg Hydrochlorothiazide.
The tablets contain Lactose anhydrous.
For a full list of excipients, see section 6.1.
3. PHARMACEUTICAL FORM
Tablet.
Losartan potassium and Hydrochlorothiazide 50mg/12.5mg Tablets are, Yellow, capsule shaped, biconvex, film-coated tablets, debossed with ‘50’ on one side and plain on the other side
4. CLINICAL PARTICULARS
4.1 Therapeutic indications
For the treatment of hypertension in patients whose blood pressure is not adequately controlled on hydrochlorothiazide or losartan monotherapy.
In hypertensive patients with left ventricular hypertrophy a reduced risk of stroke was demonstrated with losartan administered usually in combination with HCTZ. The data do not support the use of losartan for this indication in black patients (see section 4.4 Special warnings and Precautions for Use-Race and section 5.1 Pharmacodynamic Properties, LIFE study, Race.
4.2 Posology and method of administration
Where possible titration with the individual components (i.e. losartan and hydrochlorothiazide) is recommended.
When clinically appropriate direct change from monotherapy to the fixed combinations may be considered in patients whose blood pressure is not adequately controlled.
The usual starting and maintenance dose is 1 tablet once daily for most patients. For patients who do not respond adequately, the dosage may be increased to 2 tablets once daily. The maximum dose is 2 tablets once daily. In general, the antihypertensive effect is attained within three weeks after initiation of therapy.
Reduction in the risk of stroke in hypertensive patients with left ventricular hypertrophy
The usual starting dose is 50 mg of losartan once daily. If goal blood pressure is not reached with losartan 50 mg, therapy should be titrated using a combination of losartan and a low dose of hydrochlorothiazide (12.5 mg) and, if needed the dose should then be increased to losartan 100 mg/hydrochlorothiazide 12.5 mg once daily. If necessary, the dose should be increased to losartan lOOrng/ hydrochlorothiazide 25 mg daily.
Use in the elderly. Patients over 75 years: Presently there is limited clinical experience in this group. Any therapy involving the angiotensin II antagonist, losartan, should be initiated with 25 mg losartan in these patients.
Use in renal impairment: No initial dosage adjustment is necessary in patients with mild renal impairment (i.e. creatinine clearance 20-50 ml/min). Losartan
potassium and Hydrochlorothiaizde is not recommended for patients with moderate to severe renal impairment (i.e. creatinine clearance <20 ml/min) or patients on dialysis.
Use in patients with intravascular volume depletion: Losartan potassium and Hydrochlorothiaizde should not be initiated in patients who are intravascularly volume depleted (e.g. those treated with high-dose diuretics).
Use in hepatic impairment: Losartan potassium and Hydrochlorothiaizde is not recommended for patients with hepatic impairment.
Concomitant therapy: Losartan potassium and Hydrochlorothiaizde may be administered with other antihypertensive agents.
Losartan potassium and Hydrochlorothiaizde may be administered with or without food.
Use in children: Safety and efficacy in children have not been established.
4.3 Contraindications
Losartan potassium and Hydrochlorothiaizde tablet is contra-indicated in pregnancy (see 4.6 'Pregnancy and lactation'), in patients who are hypersensitive to any component of this product, in patients with anuria, and in patients who are hypersensitive to other sulphonamide-derived drugs.
4.4 Special warnings and precautions for use
Losartan and hydrochlorothiazide combination tablet
Hypersensitivity: Angioedema See 4.8 'Undesirable effects'.
Hepatic and renal impairment: Losartan potassium and Hydrochlorothiaizde is not recommended for patients with hepatic impairment or moderate to severe renal impairment (creatinine clearance <20 ml/min). (See 4.2 'Posology and method of administration'.)
Losartan
......
Renal function impairment. As a consequence of inhibiting the renin-angiotensin-aldosterone system, changes in renal function, including renal failure, have been reported (in particular, in patients whose renal function is dependent on the renin-angiotensin-aldosterone system, such as those with severe cardiac insufficiency or pre-existing renal dysfunction).
As with other drugs that affect the renin-angiotensin-aldosterone system, increases in blood urea and serum creatinine have also been reported in patients with bilateral renal artery stenosis or stenosis of the artery to a solitary kidney; these changes in renal function may be reversible upon discontinuation of therapy.
r
Caution is required in patients with significant renal disease and renal transplant recipients as there have been reports of anaemia developing in such patients treated with Losartan potassium.
Hydrochlorothiazide
Hypotension and electrolyte/fluid imbalance: As with all antihypertensive therapy, symptomatic hypotension may occur in some patients. This was rarely seen in uncomplicated hypertensive patients, but was more likely in the presence of fluid depletion or electrolyte imbalance. Periodic determination of serum electrolytes should be performed at appropriate intervals, as in any patients receiving diuretics.
Metabolic and endocrine effects
Thiazide therapy may impair glucose tolerance. Dosage adjustment of antidiabetic agents, including insulin, may be required (see 4.5 'Interaction with other medicinal productsand other forms of interaction').
Thiazides may decrease urinary calcium excretion and may cause intermittent and slight elevation of serum calcium. Marked hypercalcaemia may be evidence of hidden hyperparathyroidism. Thiazides should be discontinued before carrying out tests for parathyroid function.
Increases in cholesterol and triglyceride levels may be associated with thiazide diuretic therapy.
Thiazide therapy may precipitate hyperuricaemia and/or gout in certain patients. Because losartan decreases uric acid, losartan in combination with hydrochlorothiazide attenuates the diuretic-induced hyperuricaemia.
Other
In patients receiving thiazides, hypersensitivity reactions may occur with or without a history of allergy or bronchial asthma. Exacerbation or activation of systemic lupus erythematosus has been reported with the use of thiazides.
The use of Losartan potassium in patients with haemodynamically significant obstructive valvular disease and cardiomyopathy has not been adequately studied.
Race (Blackpatients):
There is no evidence that losartan reduces the risk of stroke in black hypertensive patients with LVH (see section 5.1 Pharmacodynamic Properties, LIFE Study Race).
4.5 Interaction with other medicinal products and other forms of Interaction
Losartan
In clinical pharmacokinetic trials no drug interactions of clinical significance have been identified with hydrochlorothiazide, digoxin, warfarin, cimetidine, phenobarbital (phenobarbitone), (see Hydrochlorothiazide', Alcohol, barbiturates, or narcotics below) ketoconazole and erythromycin. Rifampicin and fluconazole have been reported to reduce levels of active metabolite. The clinical consequences of these interactions have not been evaluated.
As with other drugs that block angiotensin II or its effects, concomitant use of other drugs, which retain potassium or may increase potassium levels (e.g. potassium-sparing diuretics, potassium supplements, or salt substitutes containing potassium) may lead to increases in serum potassium. Co-medication is not advisable.
As with other antihypertensive agents, the antihypertensive effect of losartan may be attenuated by non-steroidal anti-inflammatory drugs such as indomethacin.
Hydroch loroth iazide
When given concurrently, the following drugs may interact with thiazide diuretics:
Alcohol, barbiturates, or narcotics—potentiation of orthostatic hypotension may occur.
Antidiabetic drugs (oral agents and insulin)—dosage adjustment of the antidiabetic drug may be required.
Other antihypertensive drugs—there may be an additive effect.
Cholestyramine and colestipol resins—absorption of hydrochlorothiazide is impaired in the presence of anionic exchange resins. Single doses of either cholestyramine or colestipol resins bind the hydrochlorothiazide and reduce its absorption from the gastro-intestinal tract by up to 85% and 43%, respectively.
Corticosteroids, ACTH—there may be intensified electrolyte depletion, particularly hypokalaemia.
Pressor amines (e.g. adrenaline)—possible decreased response to pressor amines, but not sufficient to preclude their use.
Skeletal muscle relaxants, non-depolarising (e.g. tubocurarine)—possible increased responsiveness to the muscle relaxant.
Lithium—diuretic agents reduce the renal clearance of lithium and add a high risk of lithium toxicity. Therefore, concomitant use is not recommended. Refer to the prescribing information for lithium preparations before use of such preparations.
Non-steroidal anti-inflammatory drugs—in some patients, the administration of a non-steroidal anti-inflammatory agent can reduce the diuretic, natriuretic, and antihypertensive effects of diuretics.
Drug/laboratory test interactions
Because of their effects on calcium metabolism, thiazides may interfere with tests for parathyroid function (see 4.4 'Special warnings and precautions for use').
4.6 Pregnancy and lactation
Use during pregnancy
Although there is no experience with the use of Losartan potassium and Hydrochlorothiaizde in pregnant women, animal studies with losartan potassium have demonstrated foetal and neonatal injury and death, the mechanism of which is believed to be pharmacologically mediated through effects on the renin-angiotensin system.
In humans, foetal renal perfusion, which is dependent upon the development of the renin-angiotensin system, begins in the second trimester; thus, risk to the foetus increases if Losartan potassium and Hydrochlorothiaizde is administered during the second or third trimesters of pregnancy.
Thiazides cross the placental barrier and appear in cord blood. The routine use of diuretics in otherwise healthy pregnant women is not recommended and exposes mother and foetus to unnecessary hazard, including foetal or neonatal jaundice, thrombocytopenia and possibly other adverse reactions which have occurred in the adult. Diuretics do not prevent development of toxaemia of pregnancy and there is no satisfactory evidence that they are useful in the treatment of toxaemia.
When used in pregnancy during the second and third trimesters, drugs that act directly on the renin-angiotensin system can cause injury and even death to the developing foetus. When pregnancy is detected, Losartan potassium and Hydrochlorothiaizde should be discontinued as soon as possible.
Use during lactation
It is not known whether losartan is excreted in human milk. Significant levels of losartan and the active metabolite were shown to be present in rat milk. Thiazides appear in human milk. Because of the potential for adverse effects on the breastfeeding infant, a decision should be made whether to discontinue breast-feeding or discontinue the drug, taking into account the importance of the drug to the mother.
4.7 Effects on ability to drive and use machines
There are no data to suggest that Losartan potassium and Hydrochlorothiaizde affects the ability to drive and use machines.
4.8 Undesirable effects
In clinical trials with the combination tablet of losartan and hydrochlorothiazide, no adverse experiences peculiar to this combination drug have been observed. Adverse experiences have been limited to those that were reported previously with losartan potassium and/or hydrochlorothiazide. The overall incidence of adverse experiences reported with the combination was comparable to placebo. The percentage of discontinuations of therapy was also comparable to placebo. For the most part, adverse experiences have been mild and transient in nature and have not required discontinuation of therapy.
In controlled clinical trials for essential hypertension, dizziness was the only adverse experience reported as drug related that occurred with an incidence greater than placebo in 1% or more of patients treated with losartan potassium-hydrochlorothiazide .
In a controlled trial in hypertensive patients with left ventricular hypertrophy, losartan used usually with hydrochlorothiazide was generally well tolerated. The most common drug-related side effects were dizziness, asthenia/fatigue, and vertigo.
The following adverse reactions have been reported in post-marketing experience: Hypersensitivity
Anaphylactic reactions, angioedema including swelling of the larynx and glottis causing airway obstruction and/or swelling of the face, lips, pharynx, and/or tongue has been reported rarely in patients treated with losartan; some of these patients previously experienced angioedema with other drugs including ACE inhibitors. Vasculitis including Henoch-Schonlein purpura, has been reported rarely with losartan.
Gastro-intestinal: Hepatitis has been reported rarely in patients treated with losartan, diarrhoea.
Respiratory. Cough has been reported with losartan.
Skin: Urticaria
Additional side effects that have been seen with one of the individual components and may be potential side effects with Losartan potassium and Hydrochlorothiaizde are the following:
Losartan
Dose-related orthostatic effects, liver function abnormalities, myalgia, migraine, rash, anaemia, pruritus.
Hydrochlorothiazide
Anorexia, gastric irritation, nausea, vomiting, cramping, diarrhoea, constipation, jaundice (intrahepatic cholestatic jaundice), pancreatitis, sialoadenitis, vertigo, paraesthesiae, headache, xanthopsia, leucopenia, agranulocytosis, thrombocytopenia, aplastic anaemia, haemolytic anaemia, purpura, photosensitivity, fever, necrotising angiitis, respiratory distress (including pneumonitis and pulmonary oedema), anaphylactic reactions, toxic epidermal necrolysis, hyperglycaemia, glycosuria, hyperuricaemia, electrolyte imbalance (including hyponatraemia and hypokalaemia), renal dysfunction, interstitial nephritis, renal failure, muscle spasm, weakness, restlessness, transient blurred vision.
Laboratory test findings
In controlled clinical trials, clinically important changes in standard laboratory parameters were rarely associated with administration of losartan potassium -hydrochlorothiazide. Hyperkalaemia (serum potassium>5.5 mmol/1) occurred in 0.7% of patients, but in these trials discontinuation of losartan potassium-hydrochlorothiazide due to hyperkalaemia was not necessary. Serum potassium should be monitored, particularly in the elderly and patients with renal impairment. Elevations of ALT occurred rarely and usually resolved upon discontinuation of therapy.
S'
4.9 Overdose
No specific information is available on the treatment of overdosage with Losartan potassium and Hydrochlorothiaizde. Treatment is symptomatic and supportive. Therapy with Losartan potassium and Hydrochlorothiaizde should be discontinued and the patient observed closely. Suggested measures include induction of emesis if ingestion is recent, and correction of dehydration, electrolyte imbalance, hepatic coma, and hypotension by established procedures.
Losartan
Limited data are available in regard to overdosage in humans. The most likely manifestation of overdosage would be hypotension and tachycardia; bradycardia could occur from parasympathetic (vagal) stimulation. If symptomatic hypotension should occur, supportive treatment should be instituted.
Neither losartan nor the active metabolite can be removed by haemodialysis. Hydrochlorothiazide
The most common signs and symptoms observed are those caused by electrolyte depletion (hypokalaemia, hypochloraemia, hyponatraemia) and dehydration resulting from excessive diuresis. If digitalis has also been administered, hypokalaemia may accentuate cardiac arrhythmias.
The degree to which hydrochlorothiazide is removed by haemodialysis has not been established.
5. PHARMACOLOGICAL PROPERTIES
5.1 Pharmacodynamic properties
Losartan and hydrochlorothiazide combination tablet
The components of Losartan potassium and Hydrochlorothiaizde have been shown to have an additive effect on blood-pressure reduction, reducing blood pressure to a greater degree than either component alone. This effect is thought to be a result of the complimentary actions of both components. Further, as a result of its diuretic effect, hydrochlorothiazide increases plasma-renin activity, increases aldosterone secretion, decreases serum potassium, and increases the levels of angiotensin II. Administration of losartan blocks all the physiologically
relevant actions of angiotensin II and through inhibition of aldosterone could tend to attenuate the potassium loss associated with the diuretic.
Losartan has been shown to have a mild and transient uricosuric effect. Hydrochlorothiazide has been shown to cause modest increases in uric acid; the combination of losartan and hydrochlorothiazide tends to attenuate the diuretic-induced hyperuricaemia.
The antihypertensive effect of Losartan potassium and Hydrochlorothiaizde is sustained for a 24-hour period. In clinical studies of at least one year's duration, the antihypertensive effect was maintained with continued therapy. Despite the significant decrease in blood pressure, administration of Losartan potassium and Hydrochlorothiaizde had no clinically significant effect on heart rate. In clinical trials, after 12 weeks of therapy with losartan 50 mg/hydrochlorothiazide 12.5 mg, trough sitting diastolic blood pressure was reduced by an average of up to 13.2 mm Hg.
Losartan potassium and Hydrochlorothiaizde is effective in reducing blood pressure in males and females, blacks and non-blacks, and in younger (<65 years) and older (^ 65 years) patients and is effective in all degrees of hypertension.
Losartan
Losartan is an oral, specific angiotensin-II receptor (type ATi) antagonist. Angiotensin II binds to the ATi receptor found in many tissues (e.g. vascular smooth muscle, adrenal gland, kidneys, and the heart) and elicits several important biological actions, including vasoconstriction and the release of aldosterone. Angiotensin II also stimulates smooth-muscle proliferation. Based on binding and pharmacological bioassays, angiotensin II binds selectively to the ATi receptor. In vitro and in vivo, both losartan and its pharmacologically active carboxylic acid metabolite (E-3174) block all physiologically relevant actions of angiotensin II, regardless of the source or route of synthesis.
During losartan administration, removal of angiotensin-II negative feedback on renin secretion leads to increased plasma-renin activity. Increases in plasma-renin activity lead to increases in angiotensin II in plasma. Even with these increases, antihypertensive activity and suppression of plasma-aldosterone concentration are maintained, indicating effective angiotensin-II receptor blockade.
Losartan binds selectively to the ATi receptor and does not bind to or block other hormone receptors or ion channels important in cardiovascular regulation. Furthermore, losartan does not inhibit ACE (kininase II), the enzyme that degrades bradykinin. Consequently, effects not directly related to blocking the ATi receptor, such as the potentiation of bradykinin-mediated effects or the generation of oedema (losartan 1.7%, placebo 1.9%), are not associated with losartan.
Losartan has been shown to block responses to angiotensin I and angiotensin II without affecting responses to bradykinin, a finding which is consistent with the specific mechanism of action of losartan. In contrast, ACE inhibitors have been shown to block responses to angiotensin I and enhance responses to bradykinin without altering the response to angiotensin II, thus providing a pharmacodynamic distinction between losartan and ACE inhibitors.
A study was carried out which was specifically designed to assess the incidence of cough in patients treated with losartan as compared to patients treated with ACE inhibitors. In this study, the incidence of cough reported by patients receiving losartan or hydrochlorothiazide was similar and was significantly less than in patients treated with an ACE inhibitor. In addition, in an overall analysis of 16 double-blind clinical trials in 4,131 patients, the incidence of spontaneously reported cough in patients treated with losartan was similar (3.1%) to that of patients treated with placebo (2.6%) or hydrochlorothiazide (4.1%), whereas the incidence with ACE inhibitors was 8.8%.
iL
In non-diabetic hypertensive patients with proteinuria, the administration of losartan potassium significantly reduces proteinuria, fractional excretion of albumin and IgG. Losartan maintains glomerular filtration rate and reduces filtration fraction. Generally, losartan causes a decrease in serum uric acid (usually <24 micro mol/l), which was persistent in chronic therapy.
Losartan has no effect on autonomic reflexes and no sustained effect on plasma nor adrenaline.
In clinical studies, once-daily administration of losartan to patients with mild to moderate essential hypertension produced statistically significant reductions in systolic and diastolic blood pressure; in clinical studies of up to one year the antihypertensive effect was maintained. Measurement of blood pressure at trough (24 hours post-dose) relative to peak (5-6 hours post-dose) demonstrated relatively smooth blood pressure reduction over 24 hours. The antihypertensive effect paralleled the natural diurnal rhythms. Blood-pressure reduction at the end of the dosing interval was approximately 70-80% of the effect seen 5-6 hours post-dose. Discontinuation of losartan in hypertensive patients did not result in an abrupt rebound of blood pressure. Despite the significant decrease in blood pressure, administration of losartan had no clinically significant effect on heart rate.
In a study comparing losartan 50 mg with the once-daily administration of enalapril 20 mg, the antihypertensive responses were shown to be similar in both treatment groups. The efficacy of once-daily administration of losartan 50-100 mg in hypertension has also been found to be comparable to once-daily administration of atenolol 50-100 mg. In older hypertensives (^65 years), the effect of administration of losartan 50-100 mg once daily has been reported to be equivalent to felodopine extended-release 5-10 mg after 12 weeks of therapy.
Losartan is equally effective in males and females and in younger (<65 years) and older (>65 years) hypertensives. Although losartan is antihypertensive in all races, as with other drugs that affect the renin-angiotensin system, black hypertensive patients have a smaller average response to losartan monotherapy than non-black patients.
When given together with thiazide-type diuretics, the blood-pressure lowering effects of losartan are approximately additive.
LIFE Study
The Losartan Intervention For Endpoint reduction in hypertension (LIFE) study was a randomised, triple-blind, active-controlled study in 9193 hypertensive patients aged 55 to 80 years with ECG-documented left ventricular hypertrophy. Patients were randomised to once daily Losartan potassium 50 mg or atenolol 50 mg. If goal blood pressure (<140/90 mmHg) was not reached, hydrochlorothiazide (12.5 mg) was added first and, if needed, the dose of Losartan potassium or atenolol was then increased to 100 mg once daily. Other antihypertensives (e.g., increase in dose of hydrochlorothiazide therapy to 25 mg or addition of other diuretic therapy, calcium channel blockers, alpha blockers, or centrally acting agents, but not ACE inhibitors, angiotensin II antagonists or beta-blockers) were added if necessary to reach the goal blood pressure. In efforts to control blood pressure, the patients in both arms of the LIFE study were coadministered hydrochlorothiazide the majority of time they were on study drug (73.9% and 72.4% of days in the losartan and atenolol arms respectively). The mean length of follow up was 4.8 years.
The primary endpoint was the composite of cardiovascular morbidity and mortality as measured by a reduction in the combined incidence of cardiovascular death, stroke and myocardial infarction. Blood pressure was significantly lowered to similar levels in the two groups. Treatment with Losartan potassium resulted in
a 13.0% risk reduction (p=0.021, 95 % confidence interval 0.77-0.98) compared with atenolol for patients reaching the primary composite endpoint. This was mainly attributable to a reduction of the incidence of stroke. Treatment with Losartan potassium reduced the risk of stroke by 25% relative to atenolol (p=0.001 95% confidence interval 0.63-0.89). The rates of cardiovascular death and myocardial infarction were not significantly different between the treatment groups.
Race: There were 533 black patients in the study. In this group, treatment with Losartan potassium resulted in a 67% increase in risk compared with atenolol for the primary composite endpoint (p=0.033, 95% confidence interval 1.04-2.66) and a 118% increase relative to atenolol in the risk of stroke (p=0.030, 95% confidence interval 1.08-4.40).
Hydroch loroth iazide
The mechanism of the antihypertensive effect of thiazides is unknown. Thiazides do not usually affect normal blood pressure.
Hydrochlorothiazide is a diuretic and antihypertensive. It affects the distal renal tubular mechanism of electrolyte reabsorption. Hydrochlorothiazide increases excretion of sodium and chloride in approximately equivalent amounts. Natriuresis may be accompanied by some loss of potassium and bicarbonate.
After oral use, diuresis begins within 2 hours, peaks in about 4 hours and lasts about 6 to 12 hours.
\
5.2 Pharmacokinetic properties
Absorption
Losartan:
Following oral administration, losartan is well absorbed and undergoes first-pass metabolism, forming an active carboxylic acid metabolite and other inactive metabolites. The systemic bioavailability of losartan tablets is approximately 33%. Mean peak concentrations of losartan and its active metabolite are reached in 1 hour and in 3-4 hours, respectively. There was no clinically significant effect on the plasma-concentration profile of losartan when the drug was administered with a standardised meal.
Distribution
Losartan:
Both losartan and its active metabolite are ^ 99% bound to plasma proteins, primarily albumin. The volume of distribution of losartan is 34 litres. Studies in rats indicate that losartan crosses the blood-brain barrier poorly, if at all.
Hydrochlorothiazide:
Hydrochlorothiazide crosses the placental but not the blood-brain barrier and is excreted in breast milk.
Biotransformation
Losartan:
About 14% of an intravenously or orally administered dose of losartan is converted to its active metabolite. Following oral and intravenous administration of 14C-labelled losartan potassium, circulating plasma radioactivity primarily is
attributed to losartan and its active metabolite. Minimal conversion of losartan to its active metabolite was seen in about 1% of individuals studied.
In addition to the active metabolite, inactive metabolites are formed, including two major metabolites formed by hydroxylation of the butyl side chain and a minor metabolite, an N-2 tetrazole glucuronide.
Elimination
Losartan:
Plasma clearance of losartan and its active metabolite is about 600 ml/min and 50 ml/min, respectively. Renal clearance of losartan and its active metabolite is about 74 ml/min and 26 ml/min, respectively. When losartan is administered orally, about 4% of the dose is excreted unchanged in the urine, and about 6% of the dose is excreted in the urine as active metabolite. The pharmacokinetics of losartan and its active metabolite are linear with oral losartan potassium doses up to 200 mg.
Following oral administration, plasma concentrations of losartan and its active metabolite decline polyexponentially with a terminal half-life of about 2 hours and 6-9 hours, respectively. During once-daily dosing with 100 mg, neither losartan nor its active metabolite accumulates significantly in plasma.
Both biliary and urinary excretion contribute to the elimination of losartan and its metabolites. Following an oral dose of 14C-labelled losartan in man, about 35% of radioactivity is recovered in the urine and 58% in the faeces.
Hydrochlorothiazide:
Hydrochlorothiazide is not metabolised but is eliminated rapidly by the kidney. When plasma levels have been followed for at least 24 hours, the plasma half-life has been observed to vary between 5.6 and 14.8 hours. At least 61% of the oral dose is eliminated unchanged within 24 hours.
Characteristics in Patients
Losartan and hydrochlorothiazide combination tablet:
The plasma concentrations of losartan and its active metabolite and the absorption of hydrochlorothiazide in elderly hypertensives are not significantly different from those in young hypertensives.
Losartan:
Following oral administration in patients with mild to moderate alcoholic cirrhosis of the liver, plasma concentrations of losartan and its active metabolite were, respectively, 5-fold and 1.7-fold greater than those seen in young male volunteers.
Neither losartan nor the active metabolite can be removed by haemodialysis.
5.3 Preclinical safety data
The toxic potential of losartan potassium and hydrochlorothiazide was evaluated in repeated-dose oral toxicity studies for up to six months in rats and dogs. There were no findings that would preclude administration to man at the therapeutic dosage level.
There was no evidence of direct genotoxicity in studies conducted with the losartan and hydrochlorothiazide combination.
Losartan potassium and hydrochlorothiazide administration had no effect on the reproductive performance or fertility in male rats at dosage levels of up to 135 mg/kg/day losartan in combination with 33.75 mg/kg/day hydrochlorothiazide. These dosage levels provided respective plasma concentrations (AUC) for losartan, the active metabolite and hydrochlorothiazide that were approximately 260-, 120-, and 50-fold greater than those achieved in man with 50 mg losartan
potassium in combination with 12.5 mg hydrochlorothiazide. In female rats, however, the coadministration of losartan potassium and hydrochlorothiazide (10/2.5 mg/kg/day) induced a slight but statistically significant decrease in fecundity and fertility indices. Compared to plasma concentrations in man (see above) these dosage levels provided respective increases in plasma concentration (AUC) for losartan, the active metabolite, and hydrochlorothiazide of approximately 15-, 4-, and 5-fold.
There was no evidence of teratogenicity in rats or rabbits treated with losartan potassium and hydrochlorothiazide combination. Foetal toxicity in rats, as evidenced by a slight increase in supernumerary ribs in the Fi generation, was observed when females were treated prior to and throughout gestation. As observed in studies with losartan alone, adverse foetal and neonatal effects, including decreased bodyweight, mortality and/or renal toxicity, also occurred when pregnant rats were treated with losartan potassium and hydrochlorothiazide combination during late gestation and/or lactation.
6. PHARMACEUTICAL PARTICULARS
6.1 List of excipients
Core:
Lactose anhydrous Cellulose Microcrystalline Starch Pregelatinised Silica, Colloidal anhydrous Magnesium Stearate Coating:
Hypromellose Hydroxypropylcellulose Titanium dioxide Iron oxide yellow
6.2 Incompatibilities
Not known.
6.3 Shelf-life
24 months.
6.4 Special precautions for storage
Do not store above 30°C. Store in original package
6.5 Nature and contents of container
Blister pack of triplex opaque white PVC (250 microns) /PE (25 microns) /PVDC (90 microns) and 25 microns Aluminum lidding foil, which is further packed in cartons.
Blister pack of 140 microns cold forming ALU/ALU as the base and 30 microns hard tampered Aluminium foil as the lidding, which is further packed in cartons.
Packs of 28 tablets.
6.6 Special requirements for disposal
No special requirements.
7. MARKETING AUTHORISATION HOLDER
Lupin (Europe) Limited
Suite 1, Victoria Court, Bexton Road
Knutsford
Cheshire WA16 OPF United Kingdom
8. MARKETING AUTHORISATION NUMBER
PL 20092/0048
9. DATE OF FIRST AUTHORISATION/RENEWAL OF THE AUTHORISATION
10. DATE OF (PARTIAL) REVISION OF THE TEXT