amlodipine + hydrochlorothiazide + olmesartan medoxomil: clinical use

Prescribing considerations

• Confirm licensed add-on or substitution criteria and assessment on individual components.
• Correct clinically significant volume or sodium depletion before initiation.
• Use caution with renal artery stenosis, heart failure, diabetes, gout or hyperuricaemia, impaired glucose tolerance, hepatic impairment, valvular obstruction, lupus, previous photosensitivity and previous skin cancer.
• Review concurrent medicines for renin–angiotensin system duplication, nephrotoxicity, potassium effects, CYP3A4 interactions and electrolyte-dependent arrhythmia risk.
• Hydrochlorothiazide exposure is associated with cumulative non-melanoma skin-cancer risk; advise sun protection and assessment of suspicious lesions.
• Investigate severe chronic diarrhoea and weight loss for olmesartan-associated sprue-like enteropathy.

Contraindications and cautions

• Hypersensitivity to an active ingredient, dihydropyridines, sulfonamide-derived substances or an excipient
• Severe renal impairment
• Refractory hypokalaemia, hypercalcaemia or hyponatraemia, or symptomatic hyperuricaemia
• Severe hepatic insufficiency, cholestasis or biliary obstruction
• Second or third trimester of pregnancy
• Aliskiren use in diabetes or renal impairment
• Shock, severe hypotension or significant left-ventricular outflow obstruction
• Haemodynamically unstable heart failure following acute myocardial infarction

Monitoring

• Blood pressure and symptoms of postural or excessive hypotension
• Renal function, sodium and potassium before treatment and after clinically relevant changes
• Consider magnesium, calcium, uric acid and glucose according to comorbidities and clinical findings
• Fluid status and renal function when NSAIDs or other nephrotoxic medicines are introduced
• Skin for new or changing lesions and photosensitivity reactions
• Persistent gastrointestinal symptoms, particularly chronic diarrhoea and weight loss

Clinical pharmacology

Olmesartan medoxomil is a prodrug converted to the selective AT1-receptor antagonist olmesartan. Amlodipine is a vessel-selective dihydropyridine L-type calcium-channel blocker. Hydrochlorothiazide increases renal sodium and chloride excretion. Food does not materially affect bioavailability of the fixed combination.

Formulation and product differences

• The product consists of film-coated tablets; colour, shape, size and debossing differ between strengths.
• Tablets should be swallowed rather than chewed.
• The formulation is essentially sodium-free.