Telmisartan + Hydrochlorothiazide

Oral
Hypertension

CrCl (mL/min)	Dosage
≤30	Contraindicated.

Mild to moderate: Max: 40 mg/12.5 mg once daily. Severe: Contraindicated.

May be taken with or without food.

Hypersensitivity to telmisartan, hydrochlorthiazide, or sulphonamide-derived drugs, cholestasis and biliary obstructive disorder, anuria, refractory hypokalaemia, hypercalcaemia. Severe hepatic and renal (<30 mL/min) impairment. Pregnancy and lactation. Concomitant use w/ aliskiren-containing products in patients w/ DM or renal (GFR <60 mL/min) impairment.

Patient w/ intravascular hypovolaemia, severe CHF, renal artery stenosis, primary aldosteronism, aortic and mitral stenosis, obstructive hypertrophic cardiomyopathy, DM, hypercholesterolaemia, parathyroid disease, SLE, history of bronchial asthma or gout. Mild to moderate hepatic and renal impairment.

Significant: Electrolyte distrubances (e.g. hyper- or hypokalaemia, hypochloraemic alkalosis, hypomagnesaemia, hyponatraemia, hypercalcaemia), renovascular HTN, hypotension, increased cholesterol and triglyceride levels, hyperuricaemia, gout, acute transient myopia, angle-closure glaucoma, photosensitivity, SLE activation or exacerbation, renal function deterioration, hypersensitivity reactions.
Nervous: Drowsiness, dizziness, fatigue, flu-like symptoms, insomnia, headache, migraine, anxiety, depression, syncope, paraesthesia.
CV: Chest pain, tachycardia, flushing, arrhythmia.
GI: Diarrhoea, dry mouth, nausea, taste disturbances, flatulence, abdominal pain, constipation, dyspepsia, vomiting, gastritis.
Resp: Upper resp tract infection, sinusitis, pharyngitis, cough, bronchitis, dyspnoea.
Hepatic: Jaundince, abnormal liver function.
Genitourinary: Increased BUN and serum creatinine.
Endocrine: Dyslipidaemia, impotence, hyperglycaemia, glycosuria.
Musculoskeletal: Back pain, muscle pain and cramps, increased creatine phosphokinase.
Ophthalmologic: Blurred vision.
Dermatologic: Urticaria, erythema, pruritus, rash, hyperhidrosis.
Potentially Fatal: Rarely, angioedema.

PO: D

This drug may cause dizziness or drowsiness, if affected, do not drive or operate machinery.

Monitor BP, serum electrolytes, BUN, creatinine, wt, input and output, and renal function. Monitor for signs of angioedema.

Symptoms: Hypotension, tachycardia, dizziness, bradycardia, vomiting, increased serum creatinine, acute renal failure, electrolyte depletion (e.g. hypokalaemia, hypochloraemia), hypovolaemia, nausea, somnolence. Management: Symptomatic and supportive treatment. Employ gastric lavage and induce emesis. Admin of activated charcoal may be useful. Treat hypotension w/ salt and volume replacements. Monitor serum electrolytes and creatinine levels frequently.

May increase serum lithium levels and toxicity. Increased risk of hyperkalaemia w/ K-sparing diuretics, K supplements, K-containing salt substitutes, ACE inhibitors, and cyclosporin. May decrease effect of pressor amines. Reduced antihypertensive effect w/ NSAIDs. Telmisartan may increase the hypotensive effect of other antihypertensive agents. Telmisartan may increase peak plasma and trough concentrations of digoxin. Potentiated hypokalaemic effect of hydrochlorothiazide when concomitantly used w/ corticosteroids, ACTH, amphotericin, carbenoxolone, salicylic acid derivatives, and other kaliuretic diuretics. Thiazide-induced hypokalaemia or hypomagnesaemia favours the onset of digitalis-induced arrhythmia. Impaired absorption of hydrochlorothiazide in the presence of anionic exchange resins (e.g. cholestyramine, colestipol). Hydrochlorothiazide may potentiate the effect of nondepolarising skeletal muscle relaxant (e.g. tubocurarine). Thiazides may enhance the hyperglycaemic effect of β-blockers and diazoxide. May increase the risk of adverse effects of amantadine. Thiazides may reduce the excretion of cytotoxic agents (e.g. cyclophosphamide, methotrexate) and potentiate their myelosuppressive effects. Increased bioavailability of thiazides w/ anticholinergic agents (e.g. atropine, biperiden). Hydrochlorthiazide enhances hypercalcaemic effect of Ca-containing medicinal products.
Potentially Fatal: Increased risk of hypotension, hyperkalaemia, and decreased renal function (e.g. acute renal failure) when concomitantly used w/ aliskiren esp in patients w/ DM or renal impairment.

Diminished antihypertensive effect w/ yohimbine. Potentiated orthostatic hypotensive effect w/ alcohol.

May cause false-negative aldosterone/renin ratio (ARR) and may also cause false-positive analytic result w/ anti-doping test. Hydrochlorothiazide may interfere w/ parathyroid function test and decrease serum iodine w/out signs of thyroid disturbances.

Description: Telmisartan is a nonpeptide benzimidazole derivative that blocks the vasoconstrictor and aldosterone-secreting effects of angiotensin II by selectively binding to AT₁ receptors. Hydrochlorothiazide is a diuretic acting mainly at the beginning of the distal tubules. It increases the excretion of Na and Cl ions, and consequently of water, by reducing electrolyte reabsorption from the renal tubules.
Pharmacokinetics:
Absorption: Telmisartan: Rapidly absorbed from the GI tract. Bioavailability: 42% (40 mg); 58% (160 mg). Time to peak plasma concentration: 0.5-1 hr. Hydrochlorothiazide: Well absorbed from the GI tract. Bioavailability: 65-75%. Time to peak plasma concentration: Approx 1-5 hr.
Distribution: Telmisartan: Volume of distribution: 500 L. Plasma protein binding: >99.5%, primarily to albumin and α₁-acid glycoprotein. Hydrochlorothiazide: Crosses the placenta and enters breast milk. Volume of distribution: 0.83-1.14 L/kg. Plasma protein-binding: Approx 40-68%.
Metabolism: Telmisartan: Metabolised in the liver via conjugation to the inactive metabolites, acyl glucuronide.
Excretion: Telmisartan: Via faeces, 97% mainly as unchanged drug. Terminal elimination half-life: 24 hr. Hydrochlorothiazide: Via urine, ≥61% as unchanged drug. Elimination half-life: Approx 6-15 hr.

Source: National Center for Biotechnology Information. PubChem Database. Telmisartan, CID=65999, https://pubchem.ncbi.nlm.nih.gov/compound/Telmisartan (accessed on Jan. 23, 2020)

Source: National Center for Biotechnology Information. PubChem Compound Summary for CID 3639, Hydrochlorothiazide. https://pubchem.ncbi.nlm.nih.gov/compound/3639. Accessed Aug. 25, 2022.

Store between 20-25°C. Protect from moisture.

Angiotensin II Antagonists / Diuretics

C09DA07 - telmisartan and diuretics ; Belongs to the class of angiotensin II receptor blockers (ARBs) in combination with diuretics. Used in the treatment of cardiovascular disease.

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