Telmisartan

Oral
Hypertension
Adult: Initially, 40 mg once daily, may be adjusted to 20-80 mg once daily according to clinical response. Max: 80 mg once daily.
Renal impairment: Severe or on haemodialysis: Initially, 20 mg once daily.
Hepatic impairment: Mild to moderate: Max: 40 mg once daily. Severe: Contraindicated.

Oral
Cardiovascular risk reduction
Adult: 80 mg once daily.
Renal impairment: Severe or on haemodialysis: Initially, 20 mg once daily.
Hepatic impairment: Mild to moderate: Max: 40 mg once daily. Severe: Contraindicated.

May be taken with or without food.

Biliary obstructive disorders. Concomitant use with aliskiren in patient with diabetes mellitus or renal impairment (GFR<60 mL/min/1.73 m²). Severe hepatic impairment. Pregnancy.

Patient with aortic or mitral stenosis, obstructive hypertrophic cardiomyopathy, ischaemic cardiopathy, unstented unilateral or bilateral renal artery stenosis; ascites due to cirrhosis, refractory ascites, Patients undergoing major surgery or during anaesthesia. Black race. Mild to moderate hepatic and renal impairment. Lactation. Patient Counselling This drug may cause dizziness or drowsiness, if affected, do not drive or operate machinery. Monitoring Parameters Monitor blood pressure regularly; serum creatinine, electrolyte levels e.g. serum K, and BUN. Assess pregnancy status and signs of angioedema.

Significant: Hypotension, orthostatic hypotension, bradycardia, angina pectoris, tachycardia, hypertension, peripheral oedema, intermittent claudication, increased serum creatinine. Rarely, hypoglycaemia, interstitial lung disease. Blood and lymphatic system disorders: Anaemia, eosinophilia, thrombocytopenia. Cardiac disorders: Chest pain, palpitation, dyspnoea. Ear and labyrinth disorders: Tinnitus, vertigo. Eye disorders: Visual disturbance, conjunctivitis. Gastrointestinal disorders: Diarrhoea, abdominal pain, dyspepsia, flatulence, nausea, vomiting. General disorders and administration site conditions: Fatigue, asthenia, influenza-like illness. Hepatobiliary disorders: Abnormal hepatic function. Investigations: Elevated serum uric acid, increased blood creatine phosphokinase. Musculoskeletal and connective tissue disorders: Back pain, myalgia, arthralgia. Nervous system disorders: Dizziness, headache, somnolence. Psychiatric disorders: Insomnia, depression, anxiety. Renal and urinary disorders: UTI, cystitis. Respiratory, thoracic and mediastinal disorders: Upper respiratory tract infection, sinusitis, pharyngitis, cough. Skin and subcutaneous tissue disorders: Rash, pruritus, hyperhidrosis, dermatitis. Vascular disorders: Syncope, flushing.
Potentially Fatal: Hyperkalaemia, renal function deterioration characterised by oliguria, progressive azotaemia, and acute renal failure. Rarely, angioedema, toxic skin eruption, sepsis.

Symptoms: Hypotension, tachycardia, dizziness, bradycardia, elevated serum creatinine and acute renal failure. Management: Symptomatic and supportive treatment. May consider administration of activated charcoal, induce emesis, or perform gastric lavage following ingestion. If severe hypotension occurs, place the patient in supine position then administer 0.9% NaCl IV infusion to expand fluid volume.

Increased risk of hypotension with high doses of diuretics (e.g. furosemide, hydrochlorothiazide) and other antihypertensives. May elevate plasma concentrations of digoxin. Increased risk of hyperkalaemia with K-sparing diuretics (e.g. spironolactone, eplerenone, triamterene, amiloride), K supplements or K-containing salt substitutes; ACE inhibitors, heparin, immunosuppressants (e.g. ciclosporin, tacrolimus), trimethoprim. May reduce antihypertensive effect and deteriorate renal function with aspirin, NSAIDs including selective COX-2 inhibitors. May increase serum lithium levels and toxicity. Decreased antihypertensive effect with systemic corticosteroids.
Potentially Fatal: Dual blockade of the renin-angiotensin-aldosterone system (RAAS) by concomitant use with ACE inhibitors or aliskiren may cause an increased risk of hypotension, hyperkalaemia and impaired renal function (esp in patient with diabetes mellitus or renal impairment).

May slightly decrease bioavailability with food.

May result to false-negative aldosterone/renin ratio (ARR).

Telmisartan, a nonpeptide tetrazole derivative, is an angiotensin II type 1 (AT₁) receptor antagonist producing its BP lowering effects by selectively blocking the binding of angiotensin II to AT₁ receptors, thereby reducing angiotensin II-induced vasoconstriction aldosterone-secretion and Na reabsorption.
Onset: 1-2 hours.
Duration: Up to 24 hours.
Absorption: Rapidly absorbed from the gastrointestinal tract. Slightly reduced bioavailability with food. Absolute bioavailability: Dose-dependent: Approx 42% (40-mg dose); approx 58% (160-mg dose). Time to peak plasma concentration: Approx 0.5-1 hour.
Distribution: Volume of distribution: Approx 500 L. Plasma protein binding: >99.5% mainly to albumin and α₁-acid glycoprotein.
Metabolism: Undergoes hepatic first-pass metabolism via conjugation with glucuronic acid to form inactive acyl glucuronide metabolite.
Excretion: Entirely via faeces (97% as unchanged drug); urine (<1%). Terminal elimination half-life: Approx 24 hours.

Oral: Store at 25°C. Protect from light and moisture.

Angiotensin II Antagonists

C09CA07 - telmisartan ; Belongs to the class of angiotensin II antagonists. Used in the treatment of cardiovascular disease.